Adding upstream version 0.10.5.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/cmd/generator/main.go

@@ -0,0 +1,319 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"text/template"
+)
+
+type opType struct {
+	Op   string
+	Code string
+}
+
+func createOpType(op, code string) opType {
+	return opType{
+		Op:   op,
+		Code: code,
+	}
+}
+
+func _main() error {
+	tmpl, err := template.New("").Parse(`// Code generated by internal/cmd/generator. DO NOT EDIT!
+package encoder
+
+import (
+  "strings"
+)
+
+type CodeType int
+
+const (
+{{- range $index, $type := .CodeTypes }}
+  Code{{ $type }} CodeType = {{ $index }}
+{{- end }}
+)
+
+var opTypeStrings = [{{ .OpLen }}]string{
+{{- range $type := .OpTypes }}
+    "{{ $type.Op }}",
+{{- end }}
+}
+
+type OpType uint16
+
+const (
+{{- range $index, $type := .OpTypes }}
+  Op{{ $type.Op }} OpType = {{ $index }}
+{{- end }}
+)
+
+func (t OpType) String() string {
+  if int(t) >= {{ .OpLen }} {
+    return ""
+  }
+  return opTypeStrings[int(t)]
+}
+
+func (t OpType) CodeType() CodeType {
+  if strings.Contains(t.String(), "Struct") {
+    if strings.Contains(t.String(), "End") {
+      return CodeStructEnd
+    }
+    return CodeStructField
+  }
+  switch t {
+  case OpArray, OpArrayPtr:
+    return CodeArrayHead
+  case OpArrayElem:
+    return CodeArrayElem
+  case OpSlice, OpSlicePtr:
+    return CodeSliceHead
+  case OpSliceElem:
+    return CodeSliceElem
+  case OpMap, OpMapPtr:
+    return CodeMapHead
+  case OpMapKey:
+    return CodeMapKey
+  case OpMapValue:
+    return CodeMapValue
+  case OpMapEnd:
+    return CodeMapEnd
+  }
+
+  return CodeOp
+}
+
+func (t OpType) HeadToPtrHead() OpType {
+  if strings.Index(t.String(), "PtrHead") > 0 {
+    return t
+  }
+
+  idx := strings.Index(t.String(), "Head")
+  if idx == -1 {
+    return t
+  }
+  suffix := "PtrHead"+t.String()[idx+len("Head"):]
+
+  const toPtrOffset = 2
+  if strings.Contains(OpType(int(t) + toPtrOffset).String(), suffix) {
+    return OpType(int(t) + toPtrOffset)
+  }
+  return t
+}
+
+func (t OpType) HeadToOmitEmptyHead() OpType {
+  const toOmitEmptyOffset = 1
+  if strings.Contains(OpType(int(t) + toOmitEmptyOffset).String(), "OmitEmpty") {
+    return OpType(int(t) + toOmitEmptyOffset)
+  }
+
+  return t
+}
+
+func (t OpType) PtrHeadToHead() OpType {
+  idx := strings.Index(t.String(), "PtrHead")
+  if idx == -1 {
+    return t
+  }
+  suffix := t.String()[idx+len("Ptr"):]
+
+  const toPtrOffset = 2
+  if strings.Contains(OpType(int(t) - toPtrOffset).String(), suffix) {
+    return OpType(int(t) - toPtrOffset)
+  }
+  return t
+}
+
+func (t OpType) FieldToEnd() OpType {
+  idx := strings.Index(t.String(), "Field")
+  if idx == -1 {
+    return t
+  }
+  suffix := t.String()[idx+len("Field"):]
+  if suffix == "" || suffix == "OmitEmpty" {
+    return t
+  }
+  const toEndOffset = 2
+  if strings.Contains(OpType(int(t) + toEndOffset).String(), "End"+suffix) {
+    return OpType(int(t) + toEndOffset)
+  }
+  return t
+}
+
+func (t OpType) FieldToOmitEmptyField() OpType {
+  const toOmitEmptyOffset = 1
+  if strings.Contains(OpType(int(t) + toOmitEmptyOffset).String(), "OmitEmpty") {
+    return OpType(int(t) + toOmitEmptyOffset)
+  }
+  return t
+}
+`)
+	if err != nil {
+		return err
+	}
+	codeTypes := []string{
+		"Op",
+		"ArrayHead",
+		"ArrayElem",
+		"SliceHead",
+		"SliceElem",
+		"MapHead",
+		"MapKey",
+		"MapValue",
+		"MapEnd",
+		"Recursive",
+		"StructField",
+		"StructEnd",
+	}
+	primitiveTypes := []string{
+		"int", "uint", "float32", "float64", "bool", "string", "bytes", "number",
+		"array", "map", "slice", "struct", "MarshalJSON", "MarshalText",
+		"intString", "uintString", "float32String", "float64String", "boolString", "stringString", "numberString",
+		"intPtr", "uintPtr", "float32Ptr", "float64Ptr", "boolPtr", "stringPtr", "bytesPtr", "numberPtr",
+		"arrayPtr", "mapPtr", "slicePtr", "marshalJSONPtr", "marshalTextPtr", "interfacePtr",
+		"intPtrString", "uintPtrString", "float32PtrString", "float64PtrString", "boolPtrString", "stringPtrString", "numberPtrString",
+	}
+	primitiveTypesUpper := []string{}
+	for _, typ := range primitiveTypes {
+		primitiveTypesUpper = append(primitiveTypesUpper, strings.ToUpper(string(typ[0]))+typ[1:])
+	}
+	opTypes := []opType{
+		createOpType("End", "Op"),
+		createOpType("Interface", "Op"),
+		createOpType("Ptr", "Op"),
+		createOpType("SliceElem", "SliceElem"),
+		createOpType("SliceEnd", "Op"),
+		createOpType("ArrayElem", "ArrayElem"),
+		createOpType("ArrayEnd", "Op"),
+		createOpType("MapKey", "MapKey"),
+		createOpType("MapValue", "MapValue"),
+		createOpType("MapEnd", "Op"),
+		createOpType("Recursive", "Op"),
+		createOpType("RecursivePtr", "Op"),
+		createOpType("RecursiveEnd", "Op"),
+		createOpType("InterfaceEnd", "Op"),
+	}
+	for _, typ := range primitiveTypesUpper {
+		typ := typ
+		opTypes = append(opTypes, createOpType(typ, "Op"))
+	}
+	for _, typ := range append(primitiveTypesUpper, "") {
+		for _, ptrOrNot := range []string{"", "Ptr"} {
+			for _, opt := range []string{"", "OmitEmpty"} {
+				ptrOrNot := ptrOrNot
+				opt := opt
+				typ := typ
+
+				op := fmt.Sprintf(
+					"Struct%sHead%s%s",
+					ptrOrNot,
+					opt,
+					typ,
+				)
+				opTypes = append(opTypes, opType{
+					Op:   op,
+					Code: "StructField",
+				})
+			}
+		}
+	}
+	for _, typ := range append(primitiveTypesUpper, "") {
+		for _, opt := range []string{"", "OmitEmpty"} {
+			opt := opt
+			typ := typ
+
+			op := fmt.Sprintf(
+				"StructField%s%s",
+				opt,
+				typ,
+			)
+			opTypes = append(opTypes, opType{
+				Op:   op,
+				Code: "StructField",
+			})
+		}
+		for _, opt := range []string{"", "OmitEmpty"} {
+			opt := opt
+			typ := typ
+
+			op := fmt.Sprintf(
+				"StructEnd%s%s",
+				opt,
+				typ,
+			)
+			opTypes = append(opTypes, opType{
+				Op:   op,
+				Code: "StructEnd",
+			})
+		}
+	}
+	var b bytes.Buffer
+	if err := tmpl.Execute(&b, struct {
+		CodeTypes []string
+		OpTypes   []opType
+		OpLen     int
+	}{
+		CodeTypes: codeTypes,
+		OpTypes:   opTypes,
+		OpLen:     len(opTypes),
+	}); err != nil {
+		return err
+	}
+	path := filepath.Join(repoRoot(), "internal", "encoder", "optype.go")
+	buf, err := format.Source(b.Bytes())
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(path, buf, 0644)
+}
+
+func generateVM() error {
+	file, err := os.ReadFile("vm.go.tmpl")
+	if err != nil {
+		return err
+	}
+	fset := token.NewFileSet()
+	f, err := parser.ParseFile(fset, "", string(file), parser.ParseComments)
+	if err != nil {
+		return err
+	}
+	for _, pkg := range []string{"vm", "vm_indent", "vm_color", "vm_color_indent"} {
+		f.Name.Name = pkg
+		var buf bytes.Buffer
+		printer.Fprint(&buf, fset, f)
+		path := filepath.Join(repoRoot(), "internal", "encoder", pkg, "vm.go")
+		source, err := format.Source(buf.Bytes())
+		if err != nil {
+			return err
+		}
+		if err := os.WriteFile(path, source, 0644); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func repoRoot() string {
+	_, file, _, _ := runtime.Caller(0)
+	relativePathFromRepoRoot := filepath.Join("internal", "cmd", "generator")
+	return strings.TrimSuffix(filepath.Dir(file), relativePathFromRepoRoot)
+}
+
+//go:generate go run main.go
+func main() {
+	if err := generateVM(); err != nil {
+		panic(err)
+	}
+	if err := _main(); err != nil {
+		panic(err)
+	}
+}

internal/decoder/anonymous_field.go

@@ -0,0 +1,41 @@
+package decoder
+
+import (
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type anonymousFieldDecoder struct {
+	structType *runtime.Type
+	offset     uintptr
+	dec        Decoder
+}
+
+func newAnonymousFieldDecoder(structType *runtime.Type, offset uintptr, dec Decoder) *anonymousFieldDecoder {
+	return &anonymousFieldDecoder{
+		structType: structType,
+		offset:     offset,
+		dec:        dec,
+	}
+}
+
+func (d *anonymousFieldDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	if *(*unsafe.Pointer)(p) == nil {
+		*(*unsafe.Pointer)(p) = unsafe_New(d.structType)
+	}
+	p = *(*unsafe.Pointer)(p)
+	return d.dec.DecodeStream(s, depth, unsafe.Pointer(uintptr(p)+d.offset))
+}
+
+func (d *anonymousFieldDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	if *(*unsafe.Pointer)(p) == nil {
+		*(*unsafe.Pointer)(p) = unsafe_New(d.structType)
+	}
+	p = *(*unsafe.Pointer)(p)
+	return d.dec.Decode(ctx, cursor, depth, unsafe.Pointer(uintptr(p)+d.offset))
+}
+
+func (d *anonymousFieldDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return d.dec.DecodePath(ctx, cursor, depth)
+}

internal/decoder/array.go

@@ -0,0 +1,176 @@
+package decoder
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type arrayDecoder struct {
+	elemType     *runtime.Type
+	size         uintptr
+	valueDecoder Decoder
+	alen         int
+	structName   string
+	fieldName    string
+	zeroValue    unsafe.Pointer
+}
+
+func newArrayDecoder(dec Decoder, elemType *runtime.Type, alen int, structName, fieldName string) *arrayDecoder {
+	// workaround to avoid checkptr errors. cannot use `*(*unsafe.Pointer)(unsafe_New(elemType))` directly.
+	zeroValuePtr := unsafe_New(elemType)
+	zeroValue := **(**unsafe.Pointer)(unsafe.Pointer(&zeroValuePtr))
+	return &arrayDecoder{
+		valueDecoder: dec,
+		elemType:     elemType,
+		size:         elemType.Size(),
+		alen:         alen,
+		structName:   structName,
+		fieldName:    fieldName,
+		zeroValue:    zeroValue,
+	}
+}
+
+func (d *arrayDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+	}
+
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			return nil
+		case '[':
+			idx := 0
+			s.cursor++
+			if s.skipWhiteSpace() == ']' {
+				for idx < d.alen {
+					*(*unsafe.Pointer)(unsafe.Pointer(uintptr(p) + uintptr(idx)*d.size)) = d.zeroValue
+					idx++
+				}
+				s.cursor++
+				return nil
+			}
+			for {
+				if idx < d.alen {
+					if err := d.valueDecoder.DecodeStream(s, depth, unsafe.Pointer(uintptr(p)+uintptr(idx)*d.size)); err != nil {
+						return err
+					}
+				} else {
+					if err := s.skipValue(depth); err != nil {
+						return err
+					}
+				}
+				idx++
+				switch s.skipWhiteSpace() {
+				case ']':
+					for idx < d.alen {
+						*(*unsafe.Pointer)(unsafe.Pointer(uintptr(p) + uintptr(idx)*d.size)) = d.zeroValue
+						idx++
+					}
+					s.cursor++
+					return nil
+				case ',':
+					s.cursor++
+					continue
+				case nul:
+					if s.read() {
+						s.cursor++
+						continue
+					}
+					goto ERROR
+				default:
+					goto ERROR
+				}
+			}
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto ERROR
+		default:
+			goto ERROR
+		}
+		s.cursor++
+	}
+ERROR:
+	return errors.ErrUnexpectedEndOfJSON("array", s.totalOffset())
+}
+
+func (d *arrayDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 4
+			return cursor, nil
+		case '[':
+			idx := 0
+			cursor++
+			cursor = skipWhiteSpace(buf, cursor)
+			if buf[cursor] == ']' {
+				for idx < d.alen {
+					*(*unsafe.Pointer)(unsafe.Pointer(uintptr(p) + uintptr(idx)*d.size)) = d.zeroValue
+					idx++
+				}
+				cursor++
+				return cursor, nil
+			}
+			for {
+				if idx < d.alen {
+					c, err := d.valueDecoder.Decode(ctx, cursor, depth, unsafe.Pointer(uintptr(p)+uintptr(idx)*d.size))
+					if err != nil {
+						return 0, err
+					}
+					cursor = c
+				} else {
+					c, err := skipValue(buf, cursor, depth)
+					if err != nil {
+						return 0, err
+					}
+					cursor = c
+				}
+				idx++
+				cursor = skipWhiteSpace(buf, cursor)
+				switch buf[cursor] {
+				case ']':
+					for idx < d.alen {
+						*(*unsafe.Pointer)(unsafe.Pointer(uintptr(p) + uintptr(idx)*d.size)) = d.zeroValue
+						idx++
+					}
+					cursor++
+					return cursor, nil
+				case ',':
+					cursor++
+					continue
+				default:
+					return 0, errors.ErrInvalidCharacter(buf[cursor], "array", cursor)
+				}
+			}
+		default:
+			return 0, errors.ErrUnexpectedEndOfJSON("array", cursor)
+		}
+	}
+}
+
+func (d *arrayDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: array decoder does not support decode path")
+}

internal/decoder/assign.go

@@ -0,0 +1,438 @@
+package decoder
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+var (
+	nilValue = reflect.ValueOf(nil)
+)
+
+func AssignValue(src, dst reflect.Value) error {
+	if dst.Type().Kind() != reflect.Ptr {
+		return fmt.Errorf("invalid dst type. required pointer type: %T", dst.Type())
+	}
+	casted, err := castValue(dst.Elem().Type(), src)
+	if err != nil {
+		return err
+	}
+	dst.Elem().Set(casted)
+	return nil
+}
+
+func castValue(t reflect.Type, v reflect.Value) (reflect.Value, error) {
+	switch t.Kind() {
+	case reflect.Int:
+		vv, err := castInt(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(int(vv.Int())), nil
+	case reflect.Int8:
+		vv, err := castInt(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(int8(vv.Int())), nil
+	case reflect.Int16:
+		vv, err := castInt(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(int16(vv.Int())), nil
+	case reflect.Int32:
+		vv, err := castInt(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(int32(vv.Int())), nil
+	case reflect.Int64:
+		return castInt(v)
+	case reflect.Uint:
+		vv, err := castUint(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(uint(vv.Uint())), nil
+	case reflect.Uint8:
+		vv, err := castUint(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(uint8(vv.Uint())), nil
+	case reflect.Uint16:
+		vv, err := castUint(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(uint16(vv.Uint())), nil
+	case reflect.Uint32:
+		vv, err := castUint(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(uint32(vv.Uint())), nil
+	case reflect.Uint64:
+		return castUint(v)
+	case reflect.Uintptr:
+		vv, err := castUint(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(uintptr(vv.Uint())), nil
+	case reflect.String:
+		return castString(v)
+	case reflect.Bool:
+		return castBool(v)
+	case reflect.Float32:
+		vv, err := castFloat(v)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(float32(vv.Float())), nil
+	case reflect.Float64:
+		return castFloat(v)
+	case reflect.Array:
+		return castArray(t, v)
+	case reflect.Slice:
+		return castSlice(t, v)
+	case reflect.Map:
+		return castMap(t, v)
+	case reflect.Struct:
+		return castStruct(t, v)
+	}
+	return v, nil
+}
+
+func castInt(v reflect.Value) (reflect.Value, error) {
+	switch v.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v, nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return reflect.ValueOf(int64(v.Uint())), nil
+	case reflect.String:
+		i64, err := strconv.ParseInt(v.String(), 10, 64)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(i64), nil
+	case reflect.Bool:
+		if v.Bool() {
+			return reflect.ValueOf(int64(1)), nil
+		}
+		return reflect.ValueOf(int64(0)), nil
+	case reflect.Float32, reflect.Float64:
+		return reflect.ValueOf(int64(v.Float())), nil
+	case reflect.Array:
+		if v.Len() > 0 {
+			return castInt(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to int64 from empty array")
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castInt(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to int64 from empty slice")
+	case reflect.Interface:
+		return castInt(reflect.ValueOf(v.Interface()))
+	case reflect.Map:
+		return nilValue, fmt.Errorf("failed to cast to int64 from map")
+	case reflect.Struct:
+		return nilValue, fmt.Errorf("failed to cast to int64 from struct")
+	case reflect.Ptr:
+		return castInt(v.Elem())
+	}
+	return nilValue, fmt.Errorf("failed to cast to int64 from %s", v.Type().Kind())
+}
+
+func castUint(v reflect.Value) (reflect.Value, error) {
+	switch v.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return reflect.ValueOf(uint64(v.Int())), nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v, nil
+	case reflect.String:
+		u64, err := strconv.ParseUint(v.String(), 10, 64)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(u64), nil
+	case reflect.Bool:
+		if v.Bool() {
+			return reflect.ValueOf(uint64(1)), nil
+		}
+		return reflect.ValueOf(uint64(0)), nil
+	case reflect.Float32, reflect.Float64:
+		return reflect.ValueOf(uint64(v.Float())), nil
+	case reflect.Array:
+		if v.Len() > 0 {
+			return castUint(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to uint64 from empty array")
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castUint(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to uint64 from empty slice")
+	case reflect.Interface:
+		return castUint(reflect.ValueOf(v.Interface()))
+	case reflect.Map:
+		return nilValue, fmt.Errorf("failed to cast to uint64 from map")
+	case reflect.Struct:
+		return nilValue, fmt.Errorf("failed to cast to uint64 from struct")
+	case reflect.Ptr:
+		return castUint(v.Elem())
+	}
+	return nilValue, fmt.Errorf("failed to cast to uint64 from %s", v.Type().Kind())
+}
+
+func castString(v reflect.Value) (reflect.Value, error) {
+	switch v.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return reflect.ValueOf(fmt.Sprint(v.Int())), nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return reflect.ValueOf(fmt.Sprint(v.Uint())), nil
+	case reflect.String:
+		return v, nil
+	case reflect.Bool:
+		if v.Bool() {
+			return reflect.ValueOf("true"), nil
+		}
+		return reflect.ValueOf("false"), nil
+	case reflect.Float32, reflect.Float64:
+		return reflect.ValueOf(fmt.Sprint(v.Float())), nil
+	case reflect.Array:
+		if v.Len() > 0 {
+			return castString(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to string from empty array")
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castString(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to string from empty slice")
+	case reflect.Interface:
+		return castString(reflect.ValueOf(v.Interface()))
+	case reflect.Map:
+		return nilValue, fmt.Errorf("failed to cast to string from map")
+	case reflect.Struct:
+		return nilValue, fmt.Errorf("failed to cast to string from struct")
+	case reflect.Ptr:
+		return castString(v.Elem())
+	}
+	return nilValue, fmt.Errorf("failed to cast to string from %s", v.Type().Kind())
+}
+
+func castBool(v reflect.Value) (reflect.Value, error) {
+	switch v.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		switch v.Int() {
+		case 0:
+			return reflect.ValueOf(false), nil
+		case 1:
+			return reflect.ValueOf(true), nil
+		}
+		return nilValue, fmt.Errorf("failed to cast to bool from %d", v.Int())
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch v.Uint() {
+		case 0:
+			return reflect.ValueOf(false), nil
+		case 1:
+			return reflect.ValueOf(true), nil
+		}
+		return nilValue, fmt.Errorf("failed to cast to bool from %d", v.Uint())
+	case reflect.String:
+		b, err := strconv.ParseBool(v.String())
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(b), nil
+	case reflect.Bool:
+		return v, nil
+	case reflect.Float32, reflect.Float64:
+		switch v.Float() {
+		case 0:
+			return reflect.ValueOf(false), nil
+		case 1:
+			return reflect.ValueOf(true), nil
+		}
+		return nilValue, fmt.Errorf("failed to cast to bool from %f", v.Float())
+	case reflect.Array:
+		if v.Len() > 0 {
+			return castBool(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to string from empty array")
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castBool(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to string from empty slice")
+	case reflect.Interface:
+		return castBool(reflect.ValueOf(v.Interface()))
+	case reflect.Map:
+		return nilValue, fmt.Errorf("failed to cast to string from map")
+	case reflect.Struct:
+		return nilValue, fmt.Errorf("failed to cast to string from struct")
+	case reflect.Ptr:
+		return castBool(v.Elem())
+	}
+	return nilValue, fmt.Errorf("failed to cast to bool from %s", v.Type().Kind())
+}
+
+func castFloat(v reflect.Value) (reflect.Value, error) {
+	switch v.Type().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return reflect.ValueOf(float64(v.Int())), nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return reflect.ValueOf(float64(v.Uint())), nil
+	case reflect.String:
+		f64, err := strconv.ParseFloat(v.String(), 64)
+		if err != nil {
+			return nilValue, err
+		}
+		return reflect.ValueOf(f64), nil
+	case reflect.Bool:
+		if v.Bool() {
+			return reflect.ValueOf(float64(1)), nil
+		}
+		return reflect.ValueOf(float64(0)), nil
+	case reflect.Float32, reflect.Float64:
+		return v, nil
+	case reflect.Array:
+		if v.Len() > 0 {
+			return castFloat(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to float64 from empty array")
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castFloat(v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to float64 from empty slice")
+	case reflect.Interface:
+		return castFloat(reflect.ValueOf(v.Interface()))
+	case reflect.Map:
+		return nilValue, fmt.Errorf("failed to cast to float64 from map")
+	case reflect.Struct:
+		return nilValue, fmt.Errorf("failed to cast to float64 from struct")
+	case reflect.Ptr:
+		return castFloat(v.Elem())
+	}
+	return nilValue, fmt.Errorf("failed to cast to float64 from %s", v.Type().Kind())
+}
+
+func castArray(t reflect.Type, v reflect.Value) (reflect.Value, error) {
+	kind := v.Type().Kind()
+	if kind == reflect.Interface {
+		return castArray(t, reflect.ValueOf(v.Interface()))
+	}
+	if kind != reflect.Slice && kind != reflect.Array {
+		return nilValue, fmt.Errorf("failed to cast to array from %s", kind)
+	}
+	if t.Elem() == v.Type().Elem() {
+		return v, nil
+	}
+	if t.Len() != v.Len() {
+		return nilValue, fmt.Errorf("failed to cast [%d]array from slice of %d length", t.Len(), v.Len())
+	}
+	ret := reflect.New(t).Elem()
+	for i := 0; i < v.Len(); i++ {
+		vv, err := castValue(t.Elem(), v.Index(i))
+		if err != nil {
+			return nilValue, err
+		}
+		ret.Index(i).Set(vv)
+	}
+	return ret, nil
+}
+
+func castSlice(t reflect.Type, v reflect.Value) (reflect.Value, error) {
+	kind := v.Type().Kind()
+	if kind == reflect.Interface {
+		return castSlice(t, reflect.ValueOf(v.Interface()))
+	}
+	if kind != reflect.Slice && kind != reflect.Array {
+		return nilValue, fmt.Errorf("failed to cast to slice from %s", kind)
+	}
+	if t.Elem() == v.Type().Elem() {
+		return v, nil
+	}
+	ret := reflect.MakeSlice(t, v.Len(), v.Len())
+	for i := 0; i < v.Len(); i++ {
+		vv, err := castValue(t.Elem(), v.Index(i))
+		if err != nil {
+			return nilValue, err
+		}
+		ret.Index(i).Set(vv)
+	}
+	return ret, nil
+}
+
+func castMap(t reflect.Type, v reflect.Value) (reflect.Value, error) {
+	ret := reflect.MakeMap(t)
+	switch v.Type().Kind() {
+	case reflect.Map:
+		iter := v.MapRange()
+		for iter.Next() {
+			key, err := castValue(t.Key(), iter.Key())
+			if err != nil {
+				return nilValue, err
+			}
+			value, err := castValue(t.Elem(), iter.Value())
+			if err != nil {
+				return nilValue, err
+			}
+			ret.SetMapIndex(key, value)
+		}
+		return ret, nil
+	case reflect.Interface:
+		return castMap(t, reflect.ValueOf(v.Interface()))
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castMap(t, v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to map from empty slice")
+	}
+	return nilValue, fmt.Errorf("failed to cast to map from %s", v.Type().Kind())
+}
+
+func castStruct(t reflect.Type, v reflect.Value) (reflect.Value, error) {
+	ret := reflect.New(t).Elem()
+	switch v.Type().Kind() {
+	case reflect.Map:
+		iter := v.MapRange()
+		for iter.Next() {
+			key := iter.Key()
+			k, err := castString(key)
+			if err != nil {
+				return nilValue, err
+			}
+			fieldName := k.String()
+			field, ok := t.FieldByName(fieldName)
+			if ok {
+				value, err := castValue(field.Type, iter.Value())
+				if err != nil {
+					return nilValue, err
+				}
+				ret.FieldByName(fieldName).Set(value)
+			}
+		}
+		return ret, nil
+	case reflect.Struct:
+		for i := 0; i < v.Type().NumField(); i++ {
+			name := v.Type().Field(i).Name
+			ret.FieldByName(name).Set(v.FieldByName(name))
+		}
+		return ret, nil
+	case reflect.Interface:
+		return castStruct(t, reflect.ValueOf(v.Interface()))
+	case reflect.Slice:
+		if v.Len() > 0 {
+			return castStruct(t, v.Index(0))
+		}
+		return nilValue, fmt.Errorf("failed to cast to struct from empty slice")
+	default:
+		return nilValue, fmt.Errorf("failed to cast to struct from %s", v.Type().Kind())
+	}
+}

internal/decoder/bool.go

@@ -0,0 +1,83 @@
+package decoder
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type boolDecoder struct {
+	structName string
+	fieldName  string
+}
+
+func newBoolDecoder(structName, fieldName string) *boolDecoder {
+	return &boolDecoder{structName: structName, fieldName: fieldName}
+}
+
+func (d *boolDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	c := s.skipWhiteSpace()
+	for {
+		switch c {
+		case 't':
+			if err := trueBytes(s); err != nil {
+				return err
+			}
+			**(**bool)(unsafe.Pointer(&p)) = true
+			return nil
+		case 'f':
+			if err := falseBytes(s); err != nil {
+				return err
+			}
+			**(**bool)(unsafe.Pointer(&p)) = false
+			return nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			return nil
+		case nul:
+			if s.read() {
+				c = s.char()
+				continue
+			}
+			goto ERROR
+		}
+		break
+	}
+ERROR:
+	return errors.ErrUnexpectedEndOfJSON("bool", s.totalOffset())
+}
+
+func (d *boolDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	switch buf[cursor] {
+	case 't':
+		if err := validateTrue(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		**(**bool)(unsafe.Pointer(&p)) = true
+		return cursor, nil
+	case 'f':
+		if err := validateFalse(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 5
+		**(**bool)(unsafe.Pointer(&p)) = false
+		return cursor, nil
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		return cursor, nil
+	}
+	return 0, errors.ErrUnexpectedEndOfJSON("bool", cursor)
+}
+
+func (d *boolDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: bool decoder does not support decode path")
+}

internal/decoder/bytes.go

@@ -0,0 +1,118 @@
+package decoder
+
+import (
+	"encoding/base64"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type bytesDecoder struct {
+	typ           *runtime.Type
+	sliceDecoder  Decoder
+	stringDecoder *stringDecoder
+	structName    string
+	fieldName     string
+}
+
+func byteUnmarshalerSliceDecoder(typ *runtime.Type, structName string, fieldName string) Decoder {
+	var unmarshalDecoder Decoder
+	switch {
+	case runtime.PtrTo(typ).Implements(unmarshalJSONType):
+		unmarshalDecoder = newUnmarshalJSONDecoder(runtime.PtrTo(typ), structName, fieldName)
+	case runtime.PtrTo(typ).Implements(unmarshalTextType):
+		unmarshalDecoder = newUnmarshalTextDecoder(runtime.PtrTo(typ), structName, fieldName)
+	default:
+		unmarshalDecoder, _ = compileUint8(typ, structName, fieldName)
+	}
+	return newSliceDecoder(unmarshalDecoder, typ, 1, structName, fieldName)
+}
+
+func newBytesDecoder(typ *runtime.Type, structName string, fieldName string) *bytesDecoder {
+	return &bytesDecoder{
+		typ:           typ,
+		sliceDecoder:  byteUnmarshalerSliceDecoder(typ, structName, fieldName),
+		stringDecoder: newStringDecoder(structName, fieldName),
+		structName:    structName,
+		fieldName:     fieldName,
+	}
+}
+
+func (d *bytesDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamBinary(s, depth, p)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		s.reset()
+		return nil
+	}
+	decodedLen := base64.StdEncoding.DecodedLen(len(bytes))
+	buf := make([]byte, decodedLen)
+	n, err := base64.StdEncoding.Decode(buf, bytes)
+	if err != nil {
+		return err
+	}
+	*(*[]byte)(p) = buf[:n]
+	s.reset()
+	return nil
+}
+
+func (d *bytesDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.decodeBinary(ctx, cursor, depth, p)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		return c, nil
+	}
+	cursor = c
+	decodedLen := base64.StdEncoding.DecodedLen(len(bytes))
+	b := make([]byte, decodedLen)
+	n, err := base64.StdEncoding.Decode(b, bytes)
+	if err != nil {
+		return 0, err
+	}
+	*(*[]byte)(p) = b[:n]
+	return cursor, nil
+}
+
+func (d *bytesDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: []byte decoder does not support decode path")
+}
+
+func (d *bytesDecoder) decodeStreamBinary(s *Stream, depth int64, p unsafe.Pointer) ([]byte, error) {
+	c := s.skipWhiteSpace()
+	if c == '[' {
+		if d.sliceDecoder == nil {
+			return nil, &errors.UnmarshalTypeError{
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		}
+		err := d.sliceDecoder.DecodeStream(s, depth, p)
+		return nil, err
+	}
+	return d.stringDecoder.decodeStreamByte(s)
+}
+
+func (d *bytesDecoder) decodeBinary(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) ([]byte, int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	if buf[cursor] == '[' {
+		if d.sliceDecoder == nil {
+			return nil, 0, &errors.UnmarshalTypeError{
+				Type:   runtime.RType2Type(d.typ),
+				Offset: cursor,
+			}
+		}
+		c, err := d.sliceDecoder.Decode(ctx, cursor, depth, p)
+		if err != nil {
+			return nil, 0, err
+		}
+		return nil, c, nil
+	}
+	return d.stringDecoder.decodeByte(buf, cursor)
+}

internal/decoder/compile.go

@@ -0,0 +1,493 @@
+package decoder
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"unicode"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+var (
+	jsonNumberType   = reflect.TypeOf(json.Number(""))
+	typeAddr         *runtime.TypeAddr
+	cachedDecoderMap unsafe.Pointer // map[uintptr]decoder
+	cachedDecoder    []Decoder
+	initOnce         sync.Once
+)
+
+func initDecoder() {
+	initOnce.Do(func() {
+		typeAddr = runtime.AnalyzeTypeAddr()
+		if typeAddr == nil {
+			typeAddr = &runtime.TypeAddr{}
+		}
+		cachedDecoder = make([]Decoder, typeAddr.AddrRange>>typeAddr.AddrShift+1)
+	})
+}
+
+func loadDecoderMap() map[uintptr]Decoder {
+	initDecoder()
+	p := atomic.LoadPointer(&cachedDecoderMap)
+	return *(*map[uintptr]Decoder)(unsafe.Pointer(&p))
+}
+
+func storeDecoder(typ uintptr, dec Decoder, m map[uintptr]Decoder) {
+	initDecoder()
+	newDecoderMap := make(map[uintptr]Decoder, len(m)+1)
+	newDecoderMap[typ] = dec
+
+	for k, v := range m {
+		newDecoderMap[k] = v
+	}
+
+	atomic.StorePointer(&cachedDecoderMap, *(*unsafe.Pointer)(unsafe.Pointer(&newDecoderMap)))
+}
+
+func compileToGetDecoderSlowPath(typeptr uintptr, typ *runtime.Type) (Decoder, error) {
+	decoderMap := loadDecoderMap()
+	if dec, exists := decoderMap[typeptr]; exists {
+		return dec, nil
+	}
+
+	dec, err := compileHead(typ, map[uintptr]Decoder{})
+	if err != nil {
+		return nil, err
+	}
+	storeDecoder(typeptr, dec, decoderMap)
+	return dec, nil
+}
+
+func compileHead(typ *runtime.Type, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	switch {
+	case implementsUnmarshalJSONType(runtime.PtrTo(typ)):
+		return newUnmarshalJSONDecoder(runtime.PtrTo(typ), "", ""), nil
+	case runtime.PtrTo(typ).Implements(unmarshalTextType):
+		return newUnmarshalTextDecoder(runtime.PtrTo(typ), "", ""), nil
+	}
+	return compile(typ.Elem(), "", "", structTypeToDecoder)
+}
+
+func compile(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	switch {
+	case implementsUnmarshalJSONType(runtime.PtrTo(typ)):
+		return newUnmarshalJSONDecoder(runtime.PtrTo(typ), structName, fieldName), nil
+	case runtime.PtrTo(typ).Implements(unmarshalTextType):
+		return newUnmarshalTextDecoder(runtime.PtrTo(typ), structName, fieldName), nil
+	}
+
+	switch typ.Kind() {
+	case reflect.Ptr:
+		return compilePtr(typ, structName, fieldName, structTypeToDecoder)
+	case reflect.Struct:
+		return compileStruct(typ, structName, fieldName, structTypeToDecoder)
+	case reflect.Slice:
+		elem := typ.Elem()
+		if elem.Kind() == reflect.Uint8 {
+			return compileBytes(elem, structName, fieldName)
+		}
+		return compileSlice(typ, structName, fieldName, structTypeToDecoder)
+	case reflect.Array:
+		return compileArray(typ, structName, fieldName, structTypeToDecoder)
+	case reflect.Map:
+		return compileMap(typ, structName, fieldName, structTypeToDecoder)
+	case reflect.Interface:
+		return compileInterface(typ, structName, fieldName)
+	case reflect.Uintptr:
+		return compileUint(typ, structName, fieldName)
+	case reflect.Int:
+		return compileInt(typ, structName, fieldName)
+	case reflect.Int8:
+		return compileInt8(typ, structName, fieldName)
+	case reflect.Int16:
+		return compileInt16(typ, structName, fieldName)
+	case reflect.Int32:
+		return compileInt32(typ, structName, fieldName)
+	case reflect.Int64:
+		return compileInt64(typ, structName, fieldName)
+	case reflect.Uint:
+		return compileUint(typ, structName, fieldName)
+	case reflect.Uint8:
+		return compileUint8(typ, structName, fieldName)
+	case reflect.Uint16:
+		return compileUint16(typ, structName, fieldName)
+	case reflect.Uint32:
+		return compileUint32(typ, structName, fieldName)
+	case reflect.Uint64:
+		return compileUint64(typ, structName, fieldName)
+	case reflect.String:
+		return compileString(typ, structName, fieldName)
+	case reflect.Bool:
+		return compileBool(structName, fieldName)
+	case reflect.Float32:
+		return compileFloat32(structName, fieldName)
+	case reflect.Float64:
+		return compileFloat64(structName, fieldName)
+	case reflect.Func:
+		return compileFunc(typ, structName, fieldName)
+	}
+	return newInvalidDecoder(typ, structName, fieldName), nil
+}
+
+func isStringTagSupportedType(typ *runtime.Type) bool {
+	switch {
+	case implementsUnmarshalJSONType(runtime.PtrTo(typ)):
+		return false
+	case runtime.PtrTo(typ).Implements(unmarshalTextType):
+		return false
+	}
+	switch typ.Kind() {
+	case reflect.Map:
+		return false
+	case reflect.Slice:
+		return false
+	case reflect.Array:
+		return false
+	case reflect.Struct:
+		return false
+	case reflect.Interface:
+		return false
+	}
+	return true
+}
+
+func compileMapKey(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	if runtime.PtrTo(typ).Implements(unmarshalTextType) {
+		return newUnmarshalTextDecoder(runtime.PtrTo(typ), structName, fieldName), nil
+	}
+	if typ.Kind() == reflect.String {
+		return newStringDecoder(structName, fieldName), nil
+	}
+	dec, err := compile(typ, structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	for {
+		switch t := dec.(type) {
+		case *stringDecoder, *interfaceDecoder:
+			return dec, nil
+		case *boolDecoder, *intDecoder, *uintDecoder, *numberDecoder:
+			return newWrappedStringDecoder(typ, dec, structName, fieldName), nil
+		case *ptrDecoder:
+			dec = t.dec
+		default:
+			return newInvalidDecoder(typ, structName, fieldName), nil
+		}
+	}
+}
+
+func compilePtr(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	dec, err := compile(typ.Elem(), structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	return newPtrDecoder(dec, typ.Elem(), structName, fieldName), nil
+}
+
+func compileInt(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newIntDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v int64) {
+		*(*int)(p) = int(v)
+	}), nil
+}
+
+func compileInt8(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newIntDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v int64) {
+		*(*int8)(p) = int8(v)
+	}), nil
+}
+
+func compileInt16(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newIntDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v int64) {
+		*(*int16)(p) = int16(v)
+	}), nil
+}
+
+func compileInt32(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newIntDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v int64) {
+		*(*int32)(p) = int32(v)
+	}), nil
+}
+
+func compileInt64(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newIntDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v int64) {
+		*(*int64)(p) = v
+	}), nil
+}
+
+func compileUint(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newUintDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v uint64) {
+		*(*uint)(p) = uint(v)
+	}), nil
+}
+
+func compileUint8(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newUintDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v uint64) {
+		*(*uint8)(p) = uint8(v)
+	}), nil
+}
+
+func compileUint16(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newUintDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v uint64) {
+		*(*uint16)(p) = uint16(v)
+	}), nil
+}
+
+func compileUint32(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newUintDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v uint64) {
+		*(*uint32)(p) = uint32(v)
+	}), nil
+}
+
+func compileUint64(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newUintDecoder(typ, structName, fieldName, func(p unsafe.Pointer, v uint64) {
+		*(*uint64)(p) = v
+	}), nil
+}
+
+func compileFloat32(structName, fieldName string) (Decoder, error) {
+	return newFloatDecoder(structName, fieldName, func(p unsafe.Pointer, v float64) {
+		*(*float32)(p) = float32(v)
+	}), nil
+}
+
+func compileFloat64(structName, fieldName string) (Decoder, error) {
+	return newFloatDecoder(structName, fieldName, func(p unsafe.Pointer, v float64) {
+		*(*float64)(p) = v
+	}), nil
+}
+
+func compileString(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	if typ == runtime.Type2RType(jsonNumberType) {
+		return newNumberDecoder(structName, fieldName, func(p unsafe.Pointer, v json.Number) {
+			*(*json.Number)(p) = v
+		}), nil
+	}
+	return newStringDecoder(structName, fieldName), nil
+}
+
+func compileBool(structName, fieldName string) (Decoder, error) {
+	return newBoolDecoder(structName, fieldName), nil
+}
+
+func compileBytes(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newBytesDecoder(typ, structName, fieldName), nil
+}
+
+func compileSlice(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	elem := typ.Elem()
+	decoder, err := compile(elem, structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	return newSliceDecoder(decoder, elem, elem.Size(), structName, fieldName), nil
+}
+
+func compileArray(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	elem := typ.Elem()
+	decoder, err := compile(elem, structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	return newArrayDecoder(decoder, elem, typ.Len(), structName, fieldName), nil
+}
+
+func compileMap(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	keyDec, err := compileMapKey(typ.Key(), structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	valueDec, err := compile(typ.Elem(), structName, fieldName, structTypeToDecoder)
+	if err != nil {
+		return nil, err
+	}
+	return newMapDecoder(typ, typ.Key(), keyDec, typ.Elem(), valueDec, structName, fieldName), nil
+}
+
+func compileInterface(typ *runtime.Type, structName, fieldName string) (Decoder, error) {
+	return newInterfaceDecoder(typ, structName, fieldName), nil
+}
+
+func compileFunc(typ *runtime.Type, strutName, fieldName string) (Decoder, error) {
+	return newFuncDecoder(typ, strutName, fieldName), nil
+}
+
+func typeToStructTags(typ *runtime.Type) runtime.StructTags {
+	tags := runtime.StructTags{}
+	fieldNum := typ.NumField()
+	for i := 0; i < fieldNum; i++ {
+		field := typ.Field(i)
+		if runtime.IsIgnoredStructField(field) {
+			continue
+		}
+		tags = append(tags, runtime.StructTagFromField(field))
+	}
+	return tags
+}
+
+func compileStruct(typ *runtime.Type, structName, fieldName string, structTypeToDecoder map[uintptr]Decoder) (Decoder, error) {
+	fieldNum := typ.NumField()
+	fieldMap := map[string]*structFieldSet{}
+	typeptr := uintptr(unsafe.Pointer(typ))
+	if dec, exists := structTypeToDecoder[typeptr]; exists {
+		return dec, nil
+	}
+	structDec := newStructDecoder(structName, fieldName, fieldMap)
+	structTypeToDecoder[typeptr] = structDec
+	structName = typ.Name()
+	tags := typeToStructTags(typ)
+	allFields := []*structFieldSet{}
+	for i := 0; i < fieldNum; i++ {
+		field := typ.Field(i)
+		if runtime.IsIgnoredStructField(field) {
+			continue
+		}
+		isUnexportedField := unicode.IsLower([]rune(field.Name)[0])
+		tag := runtime.StructTagFromField(field)
+		dec, err := compile(runtime.Type2RType(field.Type), structName, field.Name, structTypeToDecoder)
+		if err != nil {
+			return nil, err
+		}
+		if field.Anonymous && !tag.IsTaggedKey {
+			if stDec, ok := dec.(*structDecoder); ok {
+				if runtime.Type2RType(field.Type) == typ {
+					// recursive definition
+					continue
+				}
+				for k, v := range stDec.fieldMap {
+					if tags.ExistsKey(k) {
+						continue
+					}
+					fieldSet := &structFieldSet{
+						dec:         v.dec,
+						offset:      field.Offset + v.offset,
+						isTaggedKey: v.isTaggedKey,
+						key:         k,
+						keyLen:      int64(len(k)),
+					}
+					allFields = append(allFields, fieldSet)
+				}
+			} else if pdec, ok := dec.(*ptrDecoder); ok {
+				contentDec := pdec.contentDecoder()
+				if pdec.typ == typ {
+					// recursive definition
+					continue
+				}
+				var fieldSetErr error
+				if isUnexportedField {
+					fieldSetErr = fmt.Errorf(
+						"json: cannot set embedded pointer to unexported struct: %v",
+						field.Type.Elem(),
+					)
+				}
+				if dec, ok := contentDec.(*structDecoder); ok {
+					for k, v := range dec.fieldMap {
+						if tags.ExistsKey(k) {
+							continue
+						}
+						fieldSet := &structFieldSet{
+							dec:         newAnonymousFieldDecoder(pdec.typ, v.offset, v.dec),
+							offset:      field.Offset,
+							isTaggedKey: v.isTaggedKey,
+							key:         k,
+							keyLen:      int64(len(k)),
+							err:         fieldSetErr,
+						}
+						allFields = append(allFields, fieldSet)
+					}
+				} else {
+					fieldSet := &structFieldSet{
+						dec:         pdec,
+						offset:      field.Offset,
+						isTaggedKey: tag.IsTaggedKey,
+						key:         field.Name,
+						keyLen:      int64(len(field.Name)),
+					}
+					allFields = append(allFields, fieldSet)
+				}
+			} else {
+				fieldSet := &structFieldSet{
+					dec:         dec,
+					offset:      field.Offset,
+					isTaggedKey: tag.IsTaggedKey,
+					key:         field.Name,
+					keyLen:      int64(len(field.Name)),
+				}
+				allFields = append(allFields, fieldSet)
+			}
+		} else {
+			if tag.IsString && isStringTagSupportedType(runtime.Type2RType(field.Type)) {
+				dec = newWrappedStringDecoder(runtime.Type2RType(field.Type), dec, structName, field.Name)
+			}
+			var key string
+			if tag.Key != "" {
+				key = tag.Key
+			} else {
+				key = field.Name
+			}
+			fieldSet := &structFieldSet{
+				dec:         dec,
+				offset:      field.Offset,
+				isTaggedKey: tag.IsTaggedKey,
+				key:         key,
+				keyLen:      int64(len(key)),
+			}
+			allFields = append(allFields, fieldSet)
+		}
+	}
+	for _, set := range filterDuplicatedFields(allFields) {
+		fieldMap[set.key] = set
+		lower := strings.ToLower(set.key)
+		if _, exists := fieldMap[lower]; !exists {
+			// first win
+			fieldMap[lower] = set
+		}
+	}
+	delete(structTypeToDecoder, typeptr)
+	structDec.tryOptimize()
+	return structDec, nil
+}
+
+func filterDuplicatedFields(allFields []*structFieldSet) []*structFieldSet {
+	fieldMap := map[string][]*structFieldSet{}
+	for _, field := range allFields {
+		fieldMap[field.key] = append(fieldMap[field.key], field)
+	}
+	duplicatedFieldMap := map[string]struct{}{}
+	for k, sets := range fieldMap {
+		sets = filterFieldSets(sets)
+		if len(sets) != 1 {
+			duplicatedFieldMap[k] = struct{}{}
+		}
+	}
+
+	filtered := make([]*structFieldSet, 0, len(allFields))
+	for _, field := range allFields {
+		if _, exists := duplicatedFieldMap[field.key]; exists {
+			continue
+		}
+		filtered = append(filtered, field)
+	}
+	return filtered
+}
+
+func filterFieldSets(sets []*structFieldSet) []*structFieldSet {
+	if len(sets) == 1 {
+		return sets
+	}
+	filtered := make([]*structFieldSet, 0, len(sets))
+	for _, set := range sets {
+		if set.isTaggedKey {
+			filtered = append(filtered, set)
+		}
+	}
+	return filtered
+}
+
+func implementsUnmarshalJSONType(typ *runtime.Type) bool {
+	return typ.Implements(unmarshalJSONType) || typ.Implements(unmarshalJSONContextType)
+}

internal/decoder/compile_norace.go

@@ -0,0 +1,30 @@
+//go:build !race
+// +build !race
+
+package decoder
+
+import (
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+func CompileToGetDecoder(typ *runtime.Type) (Decoder, error) {
+	initDecoder()
+	typeptr := uintptr(unsafe.Pointer(typ))
+	if typeptr > typeAddr.MaxTypeAddr {
+		return compileToGetDecoderSlowPath(typeptr, typ)
+	}
+
+	index := (typeptr - typeAddr.BaseTypeAddr) >> typeAddr.AddrShift
+	if dec := cachedDecoder[index]; dec != nil {
+		return dec, nil
+	}
+
+	dec, err := compileHead(typ, map[uintptr]Decoder{})
+	if err != nil {
+		return nil, err
+	}
+	cachedDecoder[index] = dec
+	return dec, nil
+}

internal/decoder/compile_race.go

@@ -0,0 +1,38 @@
+//go:build race
+// +build race
+
+package decoder
+
+import (
+	"sync"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+var decMu sync.RWMutex
+
+func CompileToGetDecoder(typ *runtime.Type) (Decoder, error) {
+	initDecoder()
+	typeptr := uintptr(unsafe.Pointer(typ))
+	if typeptr > typeAddr.MaxTypeAddr {
+		return compileToGetDecoderSlowPath(typeptr, typ)
+	}
+
+	index := (typeptr - typeAddr.BaseTypeAddr) >> typeAddr.AddrShift
+	decMu.RLock()
+	if dec := cachedDecoder[index]; dec != nil {
+		decMu.RUnlock()
+		return dec, nil
+	}
+	decMu.RUnlock()
+
+	dec, err := compileHead(typ, map[uintptr]Decoder{})
+	if err != nil {
+		return nil, err
+	}
+	decMu.Lock()
+	cachedDecoder[index] = dec
+	decMu.Unlock()
+	return dec, nil
+}

internal/decoder/context.go

@@ -0,0 +1,254 @@
+package decoder
+
+import (
+	"sync"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type RuntimeContext struct {
+	Buf    []byte
+	Option *Option
+}
+
+var (
+	runtimeContextPool = sync.Pool{
+		New: func() interface{} {
+			return &RuntimeContext{
+				Option: &Option{},
+			}
+		},
+	}
+)
+
+func TakeRuntimeContext() *RuntimeContext {
+	return runtimeContextPool.Get().(*RuntimeContext)
+}
+
+func ReleaseRuntimeContext(ctx *RuntimeContext) {
+	runtimeContextPool.Put(ctx)
+}
+
+var (
+	isWhiteSpace = [256]bool{}
+)
+
+func init() {
+	isWhiteSpace[' '] = true
+	isWhiteSpace['\n'] = true
+	isWhiteSpace['\t'] = true
+	isWhiteSpace['\r'] = true
+}
+
+func char(ptr unsafe.Pointer, offset int64) byte {
+	return *(*byte)(unsafe.Pointer(uintptr(ptr) + uintptr(offset)))
+}
+
+func skipWhiteSpace(buf []byte, cursor int64) int64 {
+	for isWhiteSpace[buf[cursor]] {
+		cursor++
+	}
+	return cursor
+}
+
+func skipObject(buf []byte, cursor, depth int64) (int64, error) {
+	braceCount := 1
+	for {
+		switch buf[cursor] {
+		case '{':
+			braceCount++
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+			}
+		case '}':
+			depth--
+			braceCount--
+			if braceCount == 0 {
+				return cursor + 1, nil
+			}
+		case '[':
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+			}
+		case ']':
+			depth--
+		case '"':
+			for {
+				cursor++
+				switch buf[cursor] {
+				case '\\':
+					cursor++
+					if buf[cursor] == nul {
+						return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+					}
+				case '"':
+					goto SWITCH_OUT
+				case nul:
+					return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+				}
+			}
+		case nul:
+			return 0, errors.ErrUnexpectedEndOfJSON("object of object", cursor)
+		}
+	SWITCH_OUT:
+		cursor++
+	}
+}
+
+func skipArray(buf []byte, cursor, depth int64) (int64, error) {
+	bracketCount := 1
+	for {
+		switch buf[cursor] {
+		case '[':
+			bracketCount++
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+			}
+		case ']':
+			bracketCount--
+			depth--
+			if bracketCount == 0 {
+				return cursor + 1, nil
+			}
+		case '{':
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+			}
+		case '}':
+			depth--
+		case '"':
+			for {
+				cursor++
+				switch buf[cursor] {
+				case '\\':
+					cursor++
+					if buf[cursor] == nul {
+						return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+					}
+				case '"':
+					goto SWITCH_OUT
+				case nul:
+					return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+				}
+			}
+		case nul:
+			return 0, errors.ErrUnexpectedEndOfJSON("array of object", cursor)
+		}
+	SWITCH_OUT:
+		cursor++
+	}
+}
+
+func skipValue(buf []byte, cursor, depth int64) (int64, error) {
+	for {
+		switch buf[cursor] {
+		case ' ', '\t', '\n', '\r':
+			cursor++
+			continue
+		case '{':
+			return skipObject(buf, cursor+1, depth+1)
+		case '[':
+			return skipArray(buf, cursor+1, depth+1)
+		case '"':
+			for {
+				cursor++
+				switch buf[cursor] {
+				case '\\':
+					cursor++
+					if buf[cursor] == nul {
+						return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+					}
+				case '"':
+					return cursor + 1, nil
+				case nul:
+					return 0, errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+				}
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			for {
+				cursor++
+				if floatTable[buf[cursor]] {
+					continue
+				}
+				break
+			}
+			return cursor, nil
+		case 't':
+			if err := validateTrue(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 4
+			return cursor, nil
+		case 'f':
+			if err := validateFalse(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 5
+			return cursor, nil
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 4
+			return cursor, nil
+		default:
+			return cursor, errors.ErrUnexpectedEndOfJSON("null", cursor)
+		}
+	}
+}
+
+func validateTrue(buf []byte, cursor int64) error {
+	if cursor+3 >= int64(len(buf)) {
+		return errors.ErrUnexpectedEndOfJSON("true", cursor)
+	}
+	if buf[cursor+1] != 'r' {
+		return errors.ErrInvalidCharacter(buf[cursor+1], "true", cursor)
+	}
+	if buf[cursor+2] != 'u' {
+		return errors.ErrInvalidCharacter(buf[cursor+2], "true", cursor)
+	}
+	if buf[cursor+3] != 'e' {
+		return errors.ErrInvalidCharacter(buf[cursor+3], "true", cursor)
+	}
+	return nil
+}
+
+func validateFalse(buf []byte, cursor int64) error {
+	if cursor+4 >= int64(len(buf)) {
+		return errors.ErrUnexpectedEndOfJSON("false", cursor)
+	}
+	if buf[cursor+1] != 'a' {
+		return errors.ErrInvalidCharacter(buf[cursor+1], "false", cursor)
+	}
+	if buf[cursor+2] != 'l' {
+		return errors.ErrInvalidCharacter(buf[cursor+2], "false", cursor)
+	}
+	if buf[cursor+3] != 's' {
+		return errors.ErrInvalidCharacter(buf[cursor+3], "false", cursor)
+	}
+	if buf[cursor+4] != 'e' {
+		return errors.ErrInvalidCharacter(buf[cursor+4], "false", cursor)
+	}
+	return nil
+}
+
+func validateNull(buf []byte, cursor int64) error {
+	if cursor+3 >= int64(len(buf)) {
+		return errors.ErrUnexpectedEndOfJSON("null", cursor)
+	}
+	if buf[cursor+1] != 'u' {
+		return errors.ErrInvalidCharacter(buf[cursor+1], "null", cursor)
+	}
+	if buf[cursor+2] != 'l' {
+		return errors.ErrInvalidCharacter(buf[cursor+2], "null", cursor)
+	}
+	if buf[cursor+3] != 'l' {
+		return errors.ErrInvalidCharacter(buf[cursor+3], "null", cursor)
+	}
+	return nil
+}

internal/decoder/float.go

@@ -0,0 +1,170 @@
+package decoder
+
+import (
+	"strconv"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type floatDecoder struct {
+	op         func(unsafe.Pointer, float64)
+	structName string
+	fieldName  string
+}
+
+func newFloatDecoder(structName, fieldName string, op func(unsafe.Pointer, float64)) *floatDecoder {
+	return &floatDecoder{op: op, structName: structName, fieldName: fieldName}
+}
+
+var (
+	floatTable = [256]bool{
+		'0': true,
+		'1': true,
+		'2': true,
+		'3': true,
+		'4': true,
+		'5': true,
+		'6': true,
+		'7': true,
+		'8': true,
+		'9': true,
+		'.': true,
+		'e': true,
+		'E': true,
+		'+': true,
+		'-': true,
+	}
+
+	validEndNumberChar = [256]bool{
+		nul:  true,
+		' ':  true,
+		'\t': true,
+		'\r': true,
+		'\n': true,
+		',':  true,
+		':':  true,
+		'}':  true,
+		']':  true,
+	}
+)
+
+func floatBytes(s *Stream) []byte {
+	start := s.cursor
+	for {
+		s.cursor++
+		if floatTable[s.char()] {
+			continue
+		} else if s.char() == nul {
+			if s.read() {
+				s.cursor-- // for retry current character
+				continue
+			}
+		}
+		break
+	}
+	return s.buf[start:s.cursor]
+}
+
+func (d *floatDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return floatBytes(s), nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto ERROR
+		default:
+			goto ERROR
+		}
+	}
+ERROR:
+	return nil, errors.ErrUnexpectedEndOfJSON("float", s.totalOffset())
+}
+
+func (d *floatDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := cursor
+			cursor++
+			for floatTable[buf[cursor]] {
+				cursor++
+			}
+			num := buf[start:cursor]
+			return num, cursor, nil
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return nil, cursor, nil
+		default:
+			return nil, 0, errors.ErrUnexpectedEndOfJSON("float", cursor)
+		}
+	}
+}
+
+func (d *floatDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		return nil
+	}
+	str := *(*string)(unsafe.Pointer(&bytes))
+	f64, err := strconv.ParseFloat(str, 64)
+	if err != nil {
+		return errors.ErrSyntax(err.Error(), s.totalOffset())
+	}
+	d.op(p, f64)
+	return nil
+}
+
+func (d *floatDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	bytes, c, err := d.decodeByte(buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		return c, nil
+	}
+	cursor = c
+	if !validEndNumberChar[buf[cursor]] {
+		return 0, errors.ErrUnexpectedEndOfJSON("float", cursor)
+	}
+	s := *(*string)(unsafe.Pointer(&bytes))
+	f64, err := strconv.ParseFloat(s, 64)
+	if err != nil {
+		return 0, errors.ErrSyntax(err.Error(), cursor)
+	}
+	d.op(p, f64)
+	return cursor, nil
+}
+
+func (d *floatDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	buf := ctx.Buf
+	bytes, c, err := d.decodeByte(buf, cursor)
+	if err != nil {
+		return nil, 0, err
+	}
+	if bytes == nil {
+		return [][]byte{nullbytes}, c, nil
+	}
+	return [][]byte{bytes}, c, nil
+}

internal/decoder/func.go

@@ -0,0 +1,146 @@
+package decoder
+
+import (
+	"bytes"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type funcDecoder struct {
+	typ        *runtime.Type
+	structName string
+	fieldName  string
+}
+
+func newFuncDecoder(typ *runtime.Type, structName, fieldName string) *funcDecoder {
+	fnDecoder := &funcDecoder{typ, structName, fieldName}
+	return fnDecoder
+}
+
+func (d *funcDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	s.skipWhiteSpace()
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	if len(src) > 0 {
+		switch src[0] {
+		case '"':
+			return &errors.UnmarshalTypeError{
+				Value:  "string",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case '[':
+			return &errors.UnmarshalTypeError{
+				Value:  "array",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case '{':
+			return &errors.UnmarshalTypeError{
+				Value:  "object",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return &errors.UnmarshalTypeError{
+				Value:  "number",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			*(*unsafe.Pointer)(p) = nil
+			return nil
+		case 't':
+			if err := trueBytes(s); err == nil {
+				return &errors.UnmarshalTypeError{
+					Value:  "boolean",
+					Type:   runtime.RType2Type(d.typ),
+					Offset: s.totalOffset(),
+				}
+			}
+		case 'f':
+			if err := falseBytes(s); err == nil {
+				return &errors.UnmarshalTypeError{
+					Value:  "boolean",
+					Type:   runtime.RType2Type(d.typ),
+					Offset: s.totalOffset(),
+				}
+			}
+		}
+	}
+	return errors.ErrInvalidBeginningOfValue(s.buf[s.cursor], s.totalOffset())
+}
+
+func (d *funcDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	if len(src) > 0 {
+		switch src[0] {
+		case '"':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "string",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case '[':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "array",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case '{':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "object",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "number",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case 'n':
+			if bytes.Equal(src, nullbytes) {
+				*(*unsafe.Pointer)(p) = nil
+				return end, nil
+			}
+		case 't':
+			if err := validateTrue(buf, start); err == nil {
+				return 0, &errors.UnmarshalTypeError{
+					Value:  "boolean",
+					Type:   runtime.RType2Type(d.typ),
+					Offset: start,
+				}
+			}
+		case 'f':
+			if err := validateFalse(buf, start); err == nil {
+				return 0, &errors.UnmarshalTypeError{
+					Value:  "boolean",
+					Type:   runtime.RType2Type(d.typ),
+					Offset: start,
+				}
+			}
+		}
+	}
+	return cursor, errors.ErrInvalidBeginningOfValue(buf[cursor], cursor)
+}
+
+func (d *funcDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: func decoder does not support decode path")
+}

internal/decoder/int.go

@@ -0,0 +1,246 @@
+package decoder
+
+import (
+	"fmt"
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type intDecoder struct {
+	typ        *runtime.Type
+	kind       reflect.Kind
+	op         func(unsafe.Pointer, int64)
+	structName string
+	fieldName  string
+}
+
+func newIntDecoder(typ *runtime.Type, structName, fieldName string, op func(unsafe.Pointer, int64)) *intDecoder {
+	return &intDecoder{
+		typ:        typ,
+		kind:       typ.Kind(),
+		op:         op,
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *intDecoder) typeError(buf []byte, offset int64) *errors.UnmarshalTypeError {
+	return &errors.UnmarshalTypeError{
+		Value:  fmt.Sprintf("number %s", string(buf)),
+		Type:   runtime.RType2Type(d.typ),
+		Struct: d.structName,
+		Field:  d.fieldName,
+		Offset: offset,
+	}
+}
+
+var (
+	pow10i64 = [...]int64{
+		1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09,
+		1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18,
+	}
+	pow10i64Len = len(pow10i64)
+)
+
+func (d *intDecoder) parseInt(b []byte) (int64, error) {
+	isNegative := false
+	if b[0] == '-' {
+		b = b[1:]
+		isNegative = true
+	}
+	maxDigit := len(b)
+	if maxDigit > pow10i64Len {
+		return 0, fmt.Errorf("invalid length of number")
+	}
+	sum := int64(0)
+	for i := 0; i < maxDigit; i++ {
+		c := int64(b[i]) - 48
+		digitValue := pow10i64[maxDigit-i-1]
+		sum += c * digitValue
+	}
+	if isNegative {
+		return -1 * sum, nil
+	}
+	return sum, nil
+}
+
+var (
+	numTable = [256]bool{
+		'0': true,
+		'1': true,
+		'2': true,
+		'3': true,
+		'4': true,
+		'5': true,
+		'6': true,
+		'7': true,
+		'8': true,
+		'9': true,
+	}
+)
+
+var (
+	numZeroBuf = []byte{'0'}
+)
+
+func (d *intDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case '-':
+			start := s.cursor
+			for {
+				s.cursor++
+				if numTable[s.char()] {
+					continue
+				} else if s.char() == nul {
+					if s.read() {
+						s.cursor-- // for retry current character
+						continue
+					}
+				}
+				break
+			}
+			num := s.buf[start:s.cursor]
+			if len(num) < 2 {
+				goto ERROR
+			}
+			return num, nil
+		case '0':
+			s.cursor++
+			return numZeroBuf, nil
+		case '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := s.cursor
+			for {
+				s.cursor++
+				if numTable[s.char()] {
+					continue
+				} else if s.char() == nul {
+					if s.read() {
+						s.cursor-- // for retry current character
+						continue
+					}
+				}
+				break
+			}
+			num := s.buf[start:s.cursor]
+			return num, nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto ERROR
+		default:
+			return nil, d.typeError([]byte{s.char()}, s.totalOffset())
+		}
+	}
+ERROR:
+	return nil, errors.ErrUnexpectedEndOfJSON("number(integer)", s.totalOffset())
+}
+
+func (d *intDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
+	b := (*sliceHeader)(unsafe.Pointer(&buf)).data
+	for {
+		switch char(b, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case '0':
+			cursor++
+			return numZeroBuf, cursor, nil
+		case '-', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := cursor
+			cursor++
+			for numTable[char(b, cursor)] {
+				cursor++
+			}
+			num := buf[start:cursor]
+			return num, cursor, nil
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return nil, cursor, nil
+		default:
+			return nil, 0, d.typeError([]byte{char(b, cursor)}, cursor)
+		}
+	}
+}
+
+func (d *intDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		return nil
+	}
+	i64, err := d.parseInt(bytes)
+	if err != nil {
+		return d.typeError(bytes, s.totalOffset())
+	}
+	switch d.kind {
+	case reflect.Int8:
+		if i64 < -1*(1<<7) || (1<<7) <= i64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	case reflect.Int16:
+		if i64 < -1*(1<<15) || (1<<15) <= i64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	case reflect.Int32:
+		if i64 < -1*(1<<31) || (1<<31) <= i64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	}
+	d.op(p, i64)
+	s.reset()
+	return nil
+}
+
+func (d *intDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		return c, nil
+	}
+	cursor = c
+
+	i64, err := d.parseInt(bytes)
+	if err != nil {
+		return 0, d.typeError(bytes, cursor)
+	}
+	switch d.kind {
+	case reflect.Int8:
+		if i64 < -1*(1<<7) || (1<<7) <= i64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	case reflect.Int16:
+		if i64 < -1*(1<<15) || (1<<15) <= i64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	case reflect.Int32:
+		if i64 < -1*(1<<31) || (1<<31) <= i64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	}
+	d.op(p, i64)
+	return cursor, nil
+}
+
+func (d *intDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: int decoder does not support decode path")
+}

internal/decoder/interface.go

@@ -0,0 +1,528 @@
+package decoder
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/json"
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type interfaceDecoder struct {
+	typ           *runtime.Type
+	structName    string
+	fieldName     string
+	sliceDecoder  *sliceDecoder
+	mapDecoder    *mapDecoder
+	floatDecoder  *floatDecoder
+	numberDecoder *numberDecoder
+	stringDecoder *stringDecoder
+}
+
+func newEmptyInterfaceDecoder(structName, fieldName string) *interfaceDecoder {
+	ifaceDecoder := &interfaceDecoder{
+		typ:        emptyInterfaceType,
+		structName: structName,
+		fieldName:  fieldName,
+		floatDecoder: newFloatDecoder(structName, fieldName, func(p unsafe.Pointer, v float64) {
+			*(*interface{})(p) = v
+		}),
+		numberDecoder: newNumberDecoder(structName, fieldName, func(p unsafe.Pointer, v json.Number) {
+			*(*interface{})(p) = v
+		}),
+		stringDecoder: newStringDecoder(structName, fieldName),
+	}
+	ifaceDecoder.sliceDecoder = newSliceDecoder(
+		ifaceDecoder,
+		emptyInterfaceType,
+		emptyInterfaceType.Size(),
+		structName, fieldName,
+	)
+	ifaceDecoder.mapDecoder = newMapDecoder(
+		interfaceMapType,
+		stringType,
+		ifaceDecoder.stringDecoder,
+		interfaceMapType.Elem(),
+		ifaceDecoder,
+		structName,
+		fieldName,
+	)
+	return ifaceDecoder
+}
+
+func newInterfaceDecoder(typ *runtime.Type, structName, fieldName string) *interfaceDecoder {
+	emptyIfaceDecoder := newEmptyInterfaceDecoder(structName, fieldName)
+	stringDecoder := newStringDecoder(structName, fieldName)
+	return &interfaceDecoder{
+		typ:        typ,
+		structName: structName,
+		fieldName:  fieldName,
+		sliceDecoder: newSliceDecoder(
+			emptyIfaceDecoder,
+			emptyInterfaceType,
+			emptyInterfaceType.Size(),
+			structName, fieldName,
+		),
+		mapDecoder: newMapDecoder(
+			interfaceMapType,
+			stringType,
+			stringDecoder,
+			interfaceMapType.Elem(),
+			emptyIfaceDecoder,
+			structName,
+			fieldName,
+		),
+		floatDecoder: newFloatDecoder(structName, fieldName, func(p unsafe.Pointer, v float64) {
+			*(*interface{})(p) = v
+		}),
+		numberDecoder: newNumberDecoder(structName, fieldName, func(p unsafe.Pointer, v json.Number) {
+			*(*interface{})(p) = v
+		}),
+		stringDecoder: stringDecoder,
+	}
+}
+
+func (d *interfaceDecoder) numDecoder(s *Stream) Decoder {
+	if s.UseNumber {
+		return d.numberDecoder
+	}
+	return d.floatDecoder
+}
+
+var (
+	emptyInterfaceType = runtime.Type2RType(reflect.TypeOf((*interface{})(nil)).Elem())
+	EmptyInterfaceType = emptyInterfaceType
+	interfaceMapType   = runtime.Type2RType(
+		reflect.TypeOf((*map[string]interface{})(nil)).Elem(),
+	)
+	stringType = runtime.Type2RType(
+		reflect.TypeOf(""),
+	)
+)
+
+func decodeStreamUnmarshaler(s *Stream, depth int64, unmarshaler json.Unmarshaler) error {
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalJSON(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func decodeStreamUnmarshalerContext(s *Stream, depth int64, unmarshaler unmarshalerContext) error {
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalJSON(s.Option.Context, dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func decodeUnmarshaler(buf []byte, cursor, depth int64, unmarshaler json.Unmarshaler) (int64, error) {
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalJSON(dst); err != nil {
+		return 0, err
+	}
+	return end, nil
+}
+
+func decodeUnmarshalerContext(ctx *RuntimeContext, buf []byte, cursor, depth int64, unmarshaler unmarshalerContext) (int64, error) {
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalJSON(ctx.Option.Context, dst); err != nil {
+		return 0, err
+	}
+	return end, nil
+}
+
+func decodeStreamTextUnmarshaler(s *Stream, depth int64, unmarshaler encoding.TextUnmarshaler, p unsafe.Pointer) error {
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	if bytes.Equal(src, nullbytes) {
+		*(*unsafe.Pointer)(p) = nil
+		return nil
+	}
+
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if err := unmarshaler.UnmarshalText(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func decodeTextUnmarshaler(buf []byte, cursor, depth int64, unmarshaler encoding.TextUnmarshaler, p unsafe.Pointer) (int64, error) {
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	if bytes.Equal(src, nullbytes) {
+		*(*unsafe.Pointer)(p) = nil
+		return end, nil
+	}
+	if s, ok := unquoteBytes(src); ok {
+		src = s
+	}
+	if err := unmarshaler.UnmarshalText(src); err != nil {
+		return 0, err
+	}
+	return end, nil
+}
+
+func (d *interfaceDecoder) decodeStreamEmptyInterface(s *Stream, depth int64, p unsafe.Pointer) error {
+	c := s.skipWhiteSpace()
+	for {
+		switch c {
+		case '{':
+			var v map[string]interface{}
+			ptr := unsafe.Pointer(&v)
+			if err := d.mapDecoder.DecodeStream(s, depth, ptr); err != nil {
+				return err
+			}
+			*(*interface{})(p) = v
+			return nil
+		case '[':
+			var v []interface{}
+			ptr := unsafe.Pointer(&v)
+			if err := d.sliceDecoder.DecodeStream(s, depth, ptr); err != nil {
+				return err
+			}
+			*(*interface{})(p) = v
+			return nil
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return d.numDecoder(s).DecodeStream(s, depth, p)
+		case '"':
+			s.cursor++
+			start := s.cursor
+			for {
+				switch s.char() {
+				case '\\':
+					if _, err := decodeEscapeString(s, nil); err != nil {
+						return err
+					}
+				case '"':
+					literal := s.buf[start:s.cursor]
+					s.cursor++
+					*(*interface{})(p) = string(literal)
+					return nil
+				case nul:
+					if s.read() {
+						continue
+					}
+					return errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+				}
+				s.cursor++
+			}
+		case 't':
+			if err := trueBytes(s); err != nil {
+				return err
+			}
+			**(**interface{})(unsafe.Pointer(&p)) = true
+			return nil
+		case 'f':
+			if err := falseBytes(s); err != nil {
+				return err
+			}
+			**(**interface{})(unsafe.Pointer(&p)) = false
+			return nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			*(*interface{})(p) = nil
+			return nil
+		case nul:
+			if s.read() {
+				c = s.char()
+				continue
+			}
+		}
+		break
+	}
+	return errors.ErrInvalidBeginningOfValue(c, s.totalOffset())
+}
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+func (d *interfaceDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	runtimeInterfaceValue := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: p,
+	}))
+	rv := reflect.ValueOf(runtimeInterfaceValue)
+	if rv.NumMethod() > 0 && rv.CanInterface() {
+		if u, ok := rv.Interface().(unmarshalerContext); ok {
+			return decodeStreamUnmarshalerContext(s, depth, u)
+		}
+		if u, ok := rv.Interface().(json.Unmarshaler); ok {
+			return decodeStreamUnmarshaler(s, depth, u)
+		}
+		if u, ok := rv.Interface().(encoding.TextUnmarshaler); ok {
+			return decodeStreamTextUnmarshaler(s, depth, u, p)
+		}
+		if s.skipWhiteSpace() == 'n' {
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			*(*interface{})(p) = nil
+			return nil
+		}
+		return d.errUnmarshalType(rv.Type(), s.totalOffset())
+	}
+	iface := rv.Interface()
+	ifaceHeader := (*emptyInterface)(unsafe.Pointer(&iface))
+	typ := ifaceHeader.typ
+	if ifaceHeader.ptr == nil || d.typ == typ || typ == nil {
+		// concrete type is empty interface
+		return d.decodeStreamEmptyInterface(s, depth, p)
+	}
+	if typ.Kind() == reflect.Ptr && typ.Elem() == d.typ || typ.Kind() != reflect.Ptr {
+		return d.decodeStreamEmptyInterface(s, depth, p)
+	}
+	if s.skipWhiteSpace() == 'n' {
+		if err := nullBytes(s); err != nil {
+			return err
+		}
+		*(*interface{})(p) = nil
+		return nil
+	}
+	decoder, err := CompileToGetDecoder(typ)
+	if err != nil {
+		return err
+	}
+	return decoder.DecodeStream(s, depth, ifaceHeader.ptr)
+}
+
+func (d *interfaceDecoder) errUnmarshalType(typ reflect.Type, offset int64) *errors.UnmarshalTypeError {
+	return &errors.UnmarshalTypeError{
+		Value:  typ.String(),
+		Type:   typ,
+		Offset: offset,
+		Struct: d.structName,
+		Field:  d.fieldName,
+	}
+}
+
+func (d *interfaceDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	runtimeInterfaceValue := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: p,
+	}))
+	rv := reflect.ValueOf(runtimeInterfaceValue)
+	if rv.NumMethod() > 0 && rv.CanInterface() {
+		if u, ok := rv.Interface().(unmarshalerContext); ok {
+			return decodeUnmarshalerContext(ctx, buf, cursor, depth, u)
+		}
+		if u, ok := rv.Interface().(json.Unmarshaler); ok {
+			return decodeUnmarshaler(buf, cursor, depth, u)
+		}
+		if u, ok := rv.Interface().(encoding.TextUnmarshaler); ok {
+			return decodeTextUnmarshaler(buf, cursor, depth, u, p)
+		}
+		cursor = skipWhiteSpace(buf, cursor)
+		if buf[cursor] == 'n' {
+			if err := validateNull(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 4
+			**(**interface{})(unsafe.Pointer(&p)) = nil
+			return cursor, nil
+		}
+		return 0, d.errUnmarshalType(rv.Type(), cursor)
+	}
+
+	iface := rv.Interface()
+	ifaceHeader := (*emptyInterface)(unsafe.Pointer(&iface))
+	typ := ifaceHeader.typ
+	if ifaceHeader.ptr == nil || d.typ == typ || typ == nil {
+		// concrete type is empty interface
+		return d.decodeEmptyInterface(ctx, cursor, depth, p)
+	}
+	if typ.Kind() == reflect.Ptr && typ.Elem() == d.typ || typ.Kind() != reflect.Ptr {
+		return d.decodeEmptyInterface(ctx, cursor, depth, p)
+	}
+	cursor = skipWhiteSpace(buf, cursor)
+	if buf[cursor] == 'n' {
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		**(**interface{})(unsafe.Pointer(&p)) = nil
+		return cursor, nil
+	}
+	decoder, err := CompileToGetDecoder(typ)
+	if err != nil {
+		return 0, err
+	}
+	return decoder.Decode(ctx, cursor, depth, ifaceHeader.ptr)
+}
+
+func (d *interfaceDecoder) decodeEmptyInterface(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	switch buf[cursor] {
+	case '{':
+		var v map[string]interface{}
+		ptr := unsafe.Pointer(&v)
+		cursor, err := d.mapDecoder.Decode(ctx, cursor, depth, ptr)
+		if err != nil {
+			return 0, err
+		}
+		**(**interface{})(unsafe.Pointer(&p)) = v
+		return cursor, nil
+	case '[':
+		var v []interface{}
+		ptr := unsafe.Pointer(&v)
+		cursor, err := d.sliceDecoder.Decode(ctx, cursor, depth, ptr)
+		if err != nil {
+			return 0, err
+		}
+		**(**interface{})(unsafe.Pointer(&p)) = v
+		return cursor, nil
+	case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+		return d.floatDecoder.Decode(ctx, cursor, depth, p)
+	case '"':
+		var v string
+		ptr := unsafe.Pointer(&v)
+		cursor, err := d.stringDecoder.Decode(ctx, cursor, depth, ptr)
+		if err != nil {
+			return 0, err
+		}
+		**(**interface{})(unsafe.Pointer(&p)) = v
+		return cursor, nil
+	case 't':
+		if err := validateTrue(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		**(**interface{})(unsafe.Pointer(&p)) = true
+		return cursor, nil
+	case 'f':
+		if err := validateFalse(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 5
+		**(**interface{})(unsafe.Pointer(&p)) = false
+		return cursor, nil
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		**(**interface{})(unsafe.Pointer(&p)) = nil
+		return cursor, nil
+	}
+	return cursor, errors.ErrInvalidBeginningOfValue(buf[cursor], cursor)
+}
+
+func NewPathDecoder() Decoder {
+	ifaceDecoder := &interfaceDecoder{
+		typ:        emptyInterfaceType,
+		structName: "",
+		fieldName:  "",
+		floatDecoder: newFloatDecoder("", "", func(p unsafe.Pointer, v float64) {
+			*(*interface{})(p) = v
+		}),
+		numberDecoder: newNumberDecoder("", "", func(p unsafe.Pointer, v json.Number) {
+			*(*interface{})(p) = v
+		}),
+		stringDecoder: newStringDecoder("", ""),
+	}
+	ifaceDecoder.sliceDecoder = newSliceDecoder(
+		ifaceDecoder,
+		emptyInterfaceType,
+		emptyInterfaceType.Size(),
+		"", "",
+	)
+	ifaceDecoder.mapDecoder = newMapDecoder(
+		interfaceMapType,
+		stringType,
+		ifaceDecoder.stringDecoder,
+		interfaceMapType.Elem(),
+		ifaceDecoder,
+		"", "",
+	)
+	return ifaceDecoder
+}
+
+var (
+	truebytes  = []byte("true")
+	falsebytes = []byte("false")
+)
+
+func (d *interfaceDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	switch buf[cursor] {
+	case '{':
+		return d.mapDecoder.DecodePath(ctx, cursor, depth)
+	case '[':
+		return d.sliceDecoder.DecodePath(ctx, cursor, depth)
+	case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+		return d.floatDecoder.DecodePath(ctx, cursor, depth)
+	case '"':
+		return d.stringDecoder.DecodePath(ctx, cursor, depth)
+	case 't':
+		if err := validateTrue(buf, cursor); err != nil {
+			return nil, 0, err
+		}
+		cursor += 4
+		return [][]byte{truebytes}, cursor, nil
+	case 'f':
+		if err := validateFalse(buf, cursor); err != nil {
+			return nil, 0, err
+		}
+		cursor += 5
+		return [][]byte{falsebytes}, cursor, nil
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return nil, 0, err
+		}
+		cursor += 4
+		return [][]byte{nullbytes}, cursor, nil
+	}
+	return nil, cursor, errors.ErrInvalidBeginningOfValue(buf[cursor], cursor)
+}

internal/decoder/invalid.go

@@ -0,0 +1,55 @@
+package decoder
+
+import (
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type invalidDecoder struct {
+	typ        *runtime.Type
+	kind       reflect.Kind
+	structName string
+	fieldName  string
+}
+
+func newInvalidDecoder(typ *runtime.Type, structName, fieldName string) *invalidDecoder {
+	return &invalidDecoder{
+		typ:        typ,
+		kind:       typ.Kind(),
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *invalidDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	return &errors.UnmarshalTypeError{
+		Value:  "object",
+		Type:   runtime.RType2Type(d.typ),
+		Offset: s.totalOffset(),
+		Struct: d.structName,
+		Field:  d.fieldName,
+	}
+}
+
+func (d *invalidDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	return 0, &errors.UnmarshalTypeError{
+		Value:  "object",
+		Type:   runtime.RType2Type(d.typ),
+		Offset: cursor,
+		Struct: d.structName,
+		Field:  d.fieldName,
+	}
+}
+
+func (d *invalidDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, &errors.UnmarshalTypeError{
+		Value:  "object",
+		Type:   runtime.RType2Type(d.typ),
+		Offset: cursor,
+		Struct: d.structName,
+		Field:  d.fieldName,
+	}
+}

internal/decoder/map.go

@@ -0,0 +1,280 @@
+package decoder
+
+import (
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type mapDecoder struct {
+	mapType                 *runtime.Type
+	keyType                 *runtime.Type
+	valueType               *runtime.Type
+	canUseAssignFaststrType bool
+	keyDecoder              Decoder
+	valueDecoder            Decoder
+	structName              string
+	fieldName               string
+}
+
+func newMapDecoder(mapType *runtime.Type, keyType *runtime.Type, keyDec Decoder, valueType *runtime.Type, valueDec Decoder, structName, fieldName string) *mapDecoder {
+	return &mapDecoder{
+		mapType:                 mapType,
+		keyDecoder:              keyDec,
+		keyType:                 keyType,
+		canUseAssignFaststrType: canUseAssignFaststrType(keyType, valueType),
+		valueType:               valueType,
+		valueDecoder:            valueDec,
+		structName:              structName,
+		fieldName:               fieldName,
+	}
+}
+
+const (
+	mapMaxElemSize = 128
+)
+
+// See detail: https://github.com/goccy/go-json/pull/283
+func canUseAssignFaststrType(key *runtime.Type, value *runtime.Type) bool {
+	indirectElem := value.Size() > mapMaxElemSize
+	if indirectElem {
+		return false
+	}
+	return key.Kind() == reflect.String
+}
+
+//go:linkname makemap reflect.makemap
+func makemap(*runtime.Type, int) unsafe.Pointer
+
+//nolint:golint
+//go:linkname mapassign_faststr runtime.mapassign_faststr
+//go:noescape
+func mapassign_faststr(t *runtime.Type, m unsafe.Pointer, s string) unsafe.Pointer
+
+//go:linkname mapassign reflect.mapassign
+//go:noescape
+func mapassign(t *runtime.Type, m unsafe.Pointer, k, v unsafe.Pointer)
+
+func (d *mapDecoder) mapassign(t *runtime.Type, m, k, v unsafe.Pointer) {
+	if d.canUseAssignFaststrType {
+		mapV := mapassign_faststr(t, m, *(*string)(k))
+		typedmemmove(d.valueType, mapV, v)
+	} else {
+		mapassign(t, m, k, v)
+	}
+}
+
+func (d *mapDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+	}
+
+	switch s.skipWhiteSpace() {
+	case 'n':
+		if err := nullBytes(s); err != nil {
+			return err
+		}
+		**(**unsafe.Pointer)(unsafe.Pointer(&p)) = nil
+		return nil
+	case '{':
+	default:
+		return errors.ErrExpected("{ character for map value", s.totalOffset())
+	}
+	mapValue := *(*unsafe.Pointer)(p)
+	if mapValue == nil {
+		mapValue = makemap(d.mapType, 0)
+	}
+	s.cursor++
+	if s.skipWhiteSpace() == '}' {
+		*(*unsafe.Pointer)(p) = mapValue
+		s.cursor++
+		return nil
+	}
+	for {
+		k := unsafe_New(d.keyType)
+		if err := d.keyDecoder.DecodeStream(s, depth, k); err != nil {
+			return err
+		}
+		s.skipWhiteSpace()
+		if !s.equalChar(':') {
+			return errors.ErrExpected("colon after object key", s.totalOffset())
+		}
+		s.cursor++
+		v := unsafe_New(d.valueType)
+		if err := d.valueDecoder.DecodeStream(s, depth, v); err != nil {
+			return err
+		}
+		d.mapassign(d.mapType, mapValue, k, v)
+		s.skipWhiteSpace()
+		if s.equalChar('}') {
+			**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
+			s.cursor++
+			return nil
+		}
+		if !s.equalChar(',') {
+			return errors.ErrExpected("comma after object value", s.totalOffset())
+		}
+		s.cursor++
+	}
+}
+
+func (d *mapDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+
+	cursor = skipWhiteSpace(buf, cursor)
+	buflen := int64(len(buf))
+	if buflen < 2 {
+		return 0, errors.ErrExpected("{} for map", cursor)
+	}
+	switch buf[cursor] {
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		**(**unsafe.Pointer)(unsafe.Pointer(&p)) = nil
+		return cursor, nil
+	case '{':
+	default:
+		return 0, errors.ErrExpected("{ character for map value", cursor)
+	}
+	cursor++
+	cursor = skipWhiteSpace(buf, cursor)
+	mapValue := *(*unsafe.Pointer)(p)
+	if mapValue == nil {
+		mapValue = makemap(d.mapType, 0)
+	}
+	if buf[cursor] == '}' {
+		**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
+		cursor++
+		return cursor, nil
+	}
+	for {
+		k := unsafe_New(d.keyType)
+		keyCursor, err := d.keyDecoder.Decode(ctx, cursor, depth, k)
+		if err != nil {
+			return 0, err
+		}
+		cursor = skipWhiteSpace(buf, keyCursor)
+		if buf[cursor] != ':' {
+			return 0, errors.ErrExpected("colon after object key", cursor)
+		}
+		cursor++
+		v := unsafe_New(d.valueType)
+		valueCursor, err := d.valueDecoder.Decode(ctx, cursor, depth, v)
+		if err != nil {
+			return 0, err
+		}
+		d.mapassign(d.mapType, mapValue, k, v)
+		cursor = skipWhiteSpace(buf, valueCursor)
+		if buf[cursor] == '}' {
+			**(**unsafe.Pointer)(unsafe.Pointer(&p)) = mapValue
+			cursor++
+			return cursor, nil
+		}
+		if buf[cursor] != ',' {
+			return 0, errors.ErrExpected("comma after object value", cursor)
+		}
+		cursor++
+	}
+}
+
+func (d *mapDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return nil, 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+
+	cursor = skipWhiteSpace(buf, cursor)
+	buflen := int64(len(buf))
+	if buflen < 2 {
+		return nil, 0, errors.ErrExpected("{} for map", cursor)
+	}
+	switch buf[cursor] {
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return nil, 0, err
+		}
+		cursor += 4
+		return [][]byte{nullbytes}, cursor, nil
+	case '{':
+	default:
+		return nil, 0, errors.ErrExpected("{ character for map value", cursor)
+	}
+	cursor++
+	cursor = skipWhiteSpace(buf, cursor)
+	if buf[cursor] == '}' {
+		cursor++
+		return nil, cursor, nil
+	}
+	keyDecoder, ok := d.keyDecoder.(*stringDecoder)
+	if !ok {
+		return nil, 0, &errors.UnmarshalTypeError{
+			Value:  "string",
+			Type:   reflect.TypeOf(""),
+			Offset: cursor,
+			Struct: d.structName,
+			Field:  d.fieldName,
+		}
+	}
+	ret := [][]byte{}
+	for {
+		key, keyCursor, err := keyDecoder.decodeByte(buf, cursor)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(buf, keyCursor)
+		if buf[cursor] != ':' {
+			return nil, 0, errors.ErrExpected("colon after object key", cursor)
+		}
+		cursor++
+		child, found, err := ctx.Option.Path.Field(string(key))
+		if err != nil {
+			return nil, 0, err
+		}
+		if found {
+			if child != nil {
+				oldPath := ctx.Option.Path.node
+				ctx.Option.Path.node = child
+				paths, c, err := d.valueDecoder.DecodePath(ctx, cursor, depth)
+				if err != nil {
+					return nil, 0, err
+				}
+				ctx.Option.Path.node = oldPath
+				ret = append(ret, paths...)
+				cursor = c
+			} else {
+				start := cursor
+				end, err := skipValue(buf, cursor, depth)
+				if err != nil {
+					return nil, 0, err
+				}
+				ret = append(ret, buf[start:end])
+				cursor = end
+			}
+		} else {
+			c, err := skipValue(buf, cursor, depth)
+			if err != nil {
+				return nil, 0, err
+			}
+			cursor = c
+		}
+		cursor = skipWhiteSpace(buf, cursor)
+		if buf[cursor] == '}' {
+			cursor++
+			return ret, cursor, nil
+		}
+		if buf[cursor] != ',' {
+			return nil, 0, errors.ErrExpected("comma after object value", cursor)
+		}
+		cursor++
+	}
+}

internal/decoder/number.go

@@ -0,0 +1,123 @@
+package decoder
+
+import (
+	"encoding/json"
+	"strconv"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type numberDecoder struct {
+	stringDecoder *stringDecoder
+	op            func(unsafe.Pointer, json.Number)
+	structName    string
+	fieldName     string
+}
+
+func newNumberDecoder(structName, fieldName string, op func(unsafe.Pointer, json.Number)) *numberDecoder {
+	return &numberDecoder{
+		stringDecoder: newStringDecoder(structName, fieldName),
+		op:            op,
+		structName:    structName,
+		fieldName:     fieldName,
+	}
+}
+
+func (d *numberDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if _, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&bytes)), 64); err != nil {
+		return errors.ErrSyntax(err.Error(), s.totalOffset())
+	}
+	d.op(p, json.Number(string(bytes)))
+	s.reset()
+	return nil
+}
+
+func (d *numberDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if _, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&bytes)), 64); err != nil {
+		return 0, errors.ErrSyntax(err.Error(), c)
+	}
+	cursor = c
+	s := *(*string)(unsafe.Pointer(&bytes))
+	d.op(p, json.Number(s))
+	return cursor, nil
+}
+
+func (d *numberDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return nil, 0, err
+	}
+	if bytes == nil {
+		return [][]byte{nullbytes}, c, nil
+	}
+	return [][]byte{bytes}, c, nil
+}
+
+func (d *numberDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
+	start := s.cursor
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return floatBytes(s), nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case '"':
+			return d.stringDecoder.decodeStreamByte(s)
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto ERROR
+		default:
+			goto ERROR
+		}
+	}
+ERROR:
+	if s.cursor == start {
+		return nil, errors.ErrInvalidBeginningOfValue(s.char(), s.totalOffset())
+	}
+	return nil, errors.ErrUnexpectedEndOfJSON("json.Number", s.totalOffset())
+}
+
+func (d *numberDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := cursor
+			cursor++
+			for floatTable[buf[cursor]] {
+				cursor++
+			}
+			num := buf[start:cursor]
+			return num, cursor, nil
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return nil, cursor, nil
+		case '"':
+			return d.stringDecoder.decodeByte(buf, cursor)
+		default:
+			return nil, 0, errors.ErrUnexpectedEndOfJSON("json.Number", cursor)
+		}
+	}
+}

internal/decoder/option.go

@@ -0,0 +1,17 @@
+package decoder
+
+import "context"
+
+type OptionFlags uint8
+
+const (
+	FirstWinOption OptionFlags = 1 << iota
+	ContextOption
+	PathOption
+)
+
+type Option struct {
+	Flags   OptionFlags
+	Context context.Context
+	Path    *Path
+}

internal/decoder/path.go

@@ -0,0 +1,670 @@
+package decoder
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type PathString string
+
+func (s PathString) Build() (*Path, error) {
+	builder := new(PathBuilder)
+	return builder.Build([]rune(s))
+}
+
+type PathBuilder struct {
+	root                    PathNode
+	node                    PathNode
+	singleQuotePathSelector bool
+	doubleQuotePathSelector bool
+}
+
+func (b *PathBuilder) Build(buf []rune) (*Path, error) {
+	node, err := b.build(buf)
+	if err != nil {
+		return nil, err
+	}
+	return &Path{
+		node:                    node,
+		RootSelectorOnly:        node == nil,
+		SingleQuotePathSelector: b.singleQuotePathSelector,
+		DoubleQuotePathSelector: b.doubleQuotePathSelector,
+	}, nil
+}
+
+func (b *PathBuilder) build(buf []rune) (PathNode, error) {
+	if len(buf) == 0 {
+		return nil, errors.ErrEmptyPath()
+	}
+	if buf[0] != '$' {
+		return nil, errors.ErrInvalidPath("JSON Path must start with a $ character")
+	}
+	if len(buf) == 1 {
+		return nil, nil
+	}
+	buf = buf[1:]
+	offset, err := b.buildNext(buf)
+	if err != nil {
+		return nil, err
+	}
+	if len(buf) > offset {
+		return nil, errors.ErrInvalidPath("remain invalid path %q", buf[offset:])
+	}
+	return b.root, nil
+}
+
+func (b *PathBuilder) buildNextCharIfExists(buf []rune, cursor int) (int, error) {
+	if len(buf) > cursor {
+		offset, err := b.buildNext(buf[cursor:])
+		if err != nil {
+			return 0, err
+		}
+		return cursor + 1 + offset, nil
+	}
+	return cursor, nil
+}
+
+func (b *PathBuilder) buildNext(buf []rune) (int, error) {
+	switch buf[0] {
+	case '.':
+		if len(buf) == 1 {
+			return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
+		}
+		offset, err := b.buildSelector(buf[1:])
+		if err != nil {
+			return 0, err
+		}
+		return offset + 1, nil
+	case '[':
+		if len(buf) == 1 {
+			return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
+		}
+		offset, err := b.buildIndex(buf[1:])
+		if err != nil {
+			return 0, err
+		}
+		return offset + 1, nil
+	default:
+		return 0, errors.ErrInvalidPath("expect dot or left bracket character. but found %c character", buf[0])
+	}
+}
+
+func (b *PathBuilder) buildSelector(buf []rune) (int, error) {
+	switch buf[0] {
+	case '.':
+		if len(buf) == 1 {
+			return 0, errors.ErrInvalidPath("JSON Path ends with double dot character")
+		}
+		offset, err := b.buildPathRecursive(buf[1:])
+		if err != nil {
+			return 0, err
+		}
+		return 1 + offset, nil
+	case '[', ']', '$', '*':
+		return 0, errors.ErrInvalidPath("found invalid path character %c after dot", buf[0])
+	}
+	for cursor := 0; cursor < len(buf); cursor++ {
+		switch buf[cursor] {
+		case '$', '*', ']':
+			return 0, errors.ErrInvalidPath("found %c character in field selector context", buf[cursor])
+		case '.':
+			if cursor+1 >= len(buf) {
+				return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
+			}
+			selector := buf[:cursor]
+			b.addSelectorNode(string(selector))
+			offset, err := b.buildSelector(buf[cursor+1:])
+			if err != nil {
+				return 0, err
+			}
+			return cursor + 1 + offset, nil
+		case '[':
+			if cursor+1 >= len(buf) {
+				return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
+			}
+			selector := buf[:cursor]
+			b.addSelectorNode(string(selector))
+			offset, err := b.buildIndex(buf[cursor+1:])
+			if err != nil {
+				return 0, err
+			}
+			return cursor + 1 + offset, nil
+		case '"':
+			if cursor+1 >= len(buf) {
+				return 0, errors.ErrInvalidPath("JSON Path ends with double quote character")
+			}
+			offset, err := b.buildQuoteSelector(buf[cursor+1:], DoubleQuotePathSelector)
+			if err != nil {
+				return 0, err
+			}
+			return cursor + 1 + offset, nil
+		}
+	}
+	b.addSelectorNode(string(buf))
+	return len(buf), nil
+}
+
+func (b *PathBuilder) buildQuoteSelector(buf []rune, sel QuotePathSelector) (int, error) {
+	switch buf[0] {
+	case '[', ']', '$', '.', '*', '\'', '"':
+		return 0, errors.ErrInvalidPath("found invalid path character %c after quote", buf[0])
+	}
+	for cursor := 0; cursor < len(buf); cursor++ {
+		switch buf[cursor] {
+		case '\'':
+			if sel != SingleQuotePathSelector {
+				return 0, errors.ErrInvalidPath("found double quote character in field selector with single quote context")
+			}
+			if len(buf) <= cursor+1 {
+				return 0, errors.ErrInvalidPath("JSON Path ends with single quote character in field selector context")
+			}
+			if buf[cursor+1] != ']' {
+				return 0, errors.ErrInvalidPath("expect right bracket for field selector with single quote but found %c", buf[cursor+1])
+			}
+			selector := buf[:cursor]
+			b.addSelectorNode(string(selector))
+			b.singleQuotePathSelector = true
+			return b.buildNextCharIfExists(buf, cursor+2)
+		case '"':
+			if sel != DoubleQuotePathSelector {
+				return 0, errors.ErrInvalidPath("found single quote character in field selector with double quote context")
+			}
+			selector := buf[:cursor]
+			b.addSelectorNode(string(selector))
+			b.doubleQuotePathSelector = true
+			return b.buildNextCharIfExists(buf, cursor+1)
+		}
+	}
+	return 0, errors.ErrInvalidPath("couldn't find quote character in selector quote path context")
+}
+
+func (b *PathBuilder) buildPathRecursive(buf []rune) (int, error) {
+	switch buf[0] {
+	case '.', '[', ']', '$', '*':
+		return 0, errors.ErrInvalidPath("found invalid path character %c after double dot", buf[0])
+	}
+	for cursor := 0; cursor < len(buf); cursor++ {
+		switch buf[cursor] {
+		case '$', '*', ']':
+			return 0, errors.ErrInvalidPath("found %c character in field selector context", buf[cursor])
+		case '.':
+			if cursor+1 >= len(buf) {
+				return 0, errors.ErrInvalidPath("JSON Path ends with dot character")
+			}
+			selector := buf[:cursor]
+			b.addRecursiveNode(string(selector))
+			offset, err := b.buildSelector(buf[cursor+1:])
+			if err != nil {
+				return 0, err
+			}
+			return cursor + 1 + offset, nil
+		case '[':
+			if cursor+1 >= len(buf) {
+				return 0, errors.ErrInvalidPath("JSON Path ends with left bracket character")
+			}
+			selector := buf[:cursor]
+			b.addRecursiveNode(string(selector))
+			offset, err := b.buildIndex(buf[cursor+1:])
+			if err != nil {
+				return 0, err
+			}
+			return cursor + 1 + offset, nil
+		}
+	}
+	b.addRecursiveNode(string(buf))
+	return len(buf), nil
+}
+
+func (b *PathBuilder) buildIndex(buf []rune) (int, error) {
+	switch buf[0] {
+	case '.', '[', ']', '$':
+		return 0, errors.ErrInvalidPath("found invalid path character %c after left bracket", buf[0])
+	case '\'':
+		if len(buf) == 1 {
+			return 0, errors.ErrInvalidPath("JSON Path ends with single quote character")
+		}
+		offset, err := b.buildQuoteSelector(buf[1:], SingleQuotePathSelector)
+		if err != nil {
+			return 0, err
+		}
+		return 1 + offset, nil
+	case '*':
+		if len(buf) == 1 {
+			return 0, errors.ErrInvalidPath("JSON Path ends with star character")
+		}
+		if buf[1] != ']' {
+			return 0, errors.ErrInvalidPath("expect right bracket character for index all path but found %c character", buf[1])
+		}
+		b.addIndexAllNode()
+		offset := len("*]")
+		if len(buf) > 2 {
+			buildOffset, err := b.buildNext(buf[2:])
+			if err != nil {
+				return 0, err
+			}
+			return offset + buildOffset, nil
+		}
+		return offset, nil
+	}
+
+	for cursor := 0; cursor < len(buf); cursor++ {
+		switch buf[cursor] {
+		case ']':
+			index, err := strconv.ParseInt(string(buf[:cursor]), 10, 64)
+			if err != nil {
+				return 0, errors.ErrInvalidPath("%q is unexpected index path", buf[:cursor])
+			}
+			b.addIndexNode(int(index))
+			return b.buildNextCharIfExists(buf, cursor+1)
+		}
+	}
+	return 0, errors.ErrInvalidPath("couldn't find right bracket character in index path context")
+}
+
+func (b *PathBuilder) addIndexAllNode() {
+	node := newPathIndexAllNode()
+	if b.root == nil {
+		b.root = node
+		b.node = node
+	} else {
+		b.node = b.node.chain(node)
+	}
+}
+
+func (b *PathBuilder) addRecursiveNode(selector string) {
+	node := newPathRecursiveNode(selector)
+	if b.root == nil {
+		b.root = node
+		b.node = node
+	} else {
+		b.node = b.node.chain(node)
+	}
+}
+
+func (b *PathBuilder) addSelectorNode(name string) {
+	node := newPathSelectorNode(name)
+	if b.root == nil {
+		b.root = node
+		b.node = node
+	} else {
+		b.node = b.node.chain(node)
+	}
+}
+
+func (b *PathBuilder) addIndexNode(idx int) {
+	node := newPathIndexNode(idx)
+	if b.root == nil {
+		b.root = node
+		b.node = node
+	} else {
+		b.node = b.node.chain(node)
+	}
+}
+
+type QuotePathSelector int
+
+const (
+	SingleQuotePathSelector QuotePathSelector = 1
+	DoubleQuotePathSelector QuotePathSelector = 2
+)
+
+type Path struct {
+	node                    PathNode
+	RootSelectorOnly        bool
+	SingleQuotePathSelector bool
+	DoubleQuotePathSelector bool
+}
+
+func (p *Path) Field(sel string) (PathNode, bool, error) {
+	if p.node == nil {
+		return nil, false, nil
+	}
+	return p.node.Field(sel)
+}
+
+func (p *Path) Get(src, dst reflect.Value) error {
+	if p.node == nil {
+		return nil
+	}
+	return p.node.Get(src, dst)
+}
+
+func (p *Path) String() string {
+	if p.node == nil {
+		return "$"
+	}
+	return p.node.String()
+}
+
+type PathNode interface {
+	fmt.Stringer
+	Index(idx int) (PathNode, bool, error)
+	Field(fieldName string) (PathNode, bool, error)
+	Get(src, dst reflect.Value) error
+	chain(PathNode) PathNode
+	target() bool
+	single() bool
+}
+
+type BasePathNode struct {
+	child PathNode
+}
+
+func (n *BasePathNode) chain(node PathNode) PathNode {
+	n.child = node
+	return node
+}
+
+func (n *BasePathNode) target() bool {
+	return n.child == nil
+}
+
+func (n *BasePathNode) single() bool {
+	return true
+}
+
+type PathSelectorNode struct {
+	*BasePathNode
+	selector string
+}
+
+func newPathSelectorNode(selector string) *PathSelectorNode {
+	return &PathSelectorNode{
+		BasePathNode: &BasePathNode{},
+		selector:     selector,
+	}
+}
+
+func (n *PathSelectorNode) Index(idx int) (PathNode, bool, error) {
+	return nil, false, &errors.PathError{}
+}
+
+func (n *PathSelectorNode) Field(fieldName string) (PathNode, bool, error) {
+	if n.selector == fieldName {
+		return n.child, true, nil
+	}
+	return nil, false, nil
+}
+
+func (n *PathSelectorNode) Get(src, dst reflect.Value) error {
+	switch src.Type().Kind() {
+	case reflect.Map:
+		iter := src.MapRange()
+		for iter.Next() {
+			key, ok := iter.Key().Interface().(string)
+			if !ok {
+				return fmt.Errorf("invalid map key type %T", src.Type().Key())
+			}
+			child, found, err := n.Field(key)
+			if err != nil {
+				return err
+			}
+			if found {
+				if child != nil {
+					return child.Get(iter.Value(), dst)
+				}
+				return AssignValue(iter.Value(), dst)
+			}
+		}
+	case reflect.Struct:
+		typ := src.Type()
+		for i := 0; i < typ.Len(); i++ {
+			tag := runtime.StructTagFromField(typ.Field(i))
+			child, found, err := n.Field(tag.Key)
+			if err != nil {
+				return err
+			}
+			if found {
+				if child != nil {
+					return child.Get(src.Field(i), dst)
+				}
+				return AssignValue(src.Field(i), dst)
+			}
+		}
+	case reflect.Ptr:
+		return n.Get(src.Elem(), dst)
+	case reflect.Interface:
+		return n.Get(reflect.ValueOf(src.Interface()), dst)
+	case reflect.Float64, reflect.String, reflect.Bool:
+		return AssignValue(src, dst)
+	}
+	return fmt.Errorf("failed to get %s value from %s", n.selector, src.Type())
+}
+
+func (n *PathSelectorNode) String() string {
+	s := fmt.Sprintf(".%s", n.selector)
+	if n.child != nil {
+		s += n.child.String()
+	}
+	return s
+}
+
+type PathIndexNode struct {
+	*BasePathNode
+	selector int
+}
+
+func newPathIndexNode(selector int) *PathIndexNode {
+	return &PathIndexNode{
+		BasePathNode: &BasePathNode{},
+		selector:     selector,
+	}
+}
+
+func (n *PathIndexNode) Index(idx int) (PathNode, bool, error) {
+	if n.selector == idx {
+		return n.child, true, nil
+	}
+	return nil, false, nil
+}
+
+func (n *PathIndexNode) Field(fieldName string) (PathNode, bool, error) {
+	return nil, false, &errors.PathError{}
+}
+
+func (n *PathIndexNode) Get(src, dst reflect.Value) error {
+	switch src.Type().Kind() {
+	case reflect.Array, reflect.Slice:
+		if src.Len() > n.selector {
+			if n.child != nil {
+				return n.child.Get(src.Index(n.selector), dst)
+			}
+			return AssignValue(src.Index(n.selector), dst)
+		}
+	case reflect.Ptr:
+		return n.Get(src.Elem(), dst)
+	case reflect.Interface:
+		return n.Get(reflect.ValueOf(src.Interface()), dst)
+	}
+	return fmt.Errorf("failed to get [%d] value from %s", n.selector, src.Type())
+}
+
+func (n *PathIndexNode) String() string {
+	s := fmt.Sprintf("[%d]", n.selector)
+	if n.child != nil {
+		s += n.child.String()
+	}
+	return s
+}
+
+type PathIndexAllNode struct {
+	*BasePathNode
+}
+
+func newPathIndexAllNode() *PathIndexAllNode {
+	return &PathIndexAllNode{
+		BasePathNode: &BasePathNode{},
+	}
+}
+
+func (n *PathIndexAllNode) Index(idx int) (PathNode, bool, error) {
+	return n.child, true, nil
+}
+
+func (n *PathIndexAllNode) Field(fieldName string) (PathNode, bool, error) {
+	return nil, false, &errors.PathError{}
+}
+
+func (n *PathIndexAllNode) Get(src, dst reflect.Value) error {
+	switch src.Type().Kind() {
+	case reflect.Array, reflect.Slice:
+		var arr []interface{}
+		for i := 0; i < src.Len(); i++ {
+			var v interface{}
+			rv := reflect.ValueOf(&v)
+			if n.child != nil {
+				if err := n.child.Get(src.Index(i), rv); err != nil {
+					return err
+				}
+			} else {
+				if err := AssignValue(src.Index(i), rv); err != nil {
+					return err
+				}
+			}
+			arr = append(arr, v)
+		}
+		if err := AssignValue(reflect.ValueOf(arr), dst); err != nil {
+			return err
+		}
+		return nil
+	case reflect.Ptr:
+		return n.Get(src.Elem(), dst)
+	case reflect.Interface:
+		return n.Get(reflect.ValueOf(src.Interface()), dst)
+	}
+	return fmt.Errorf("failed to get all value from %s", src.Type())
+}
+
+func (n *PathIndexAllNode) String() string {
+	s := "[*]"
+	if n.child != nil {
+		s += n.child.String()
+	}
+	return s
+}
+
+type PathRecursiveNode struct {
+	*BasePathNode
+	selector string
+}
+
+func newPathRecursiveNode(selector string) *PathRecursiveNode {
+	node := newPathSelectorNode(selector)
+	return &PathRecursiveNode{
+		BasePathNode: &BasePathNode{
+			child: node,
+		},
+		selector: selector,
+	}
+}
+
+func (n *PathRecursiveNode) Field(fieldName string) (PathNode, bool, error) {
+	if n.selector == fieldName {
+		return n.child, true, nil
+	}
+	return nil, false, nil
+}
+
+func (n *PathRecursiveNode) Index(_ int) (PathNode, bool, error) {
+	return n, true, nil
+}
+
+func valueToSliceValue(v interface{}) []interface{} {
+	rv := reflect.ValueOf(v)
+	ret := []interface{}{}
+	if rv.Type().Kind() == reflect.Slice || rv.Type().Kind() == reflect.Array {
+		for i := 0; i < rv.Len(); i++ {
+			ret = append(ret, rv.Index(i).Interface())
+		}
+		return ret
+	}
+	return []interface{}{v}
+}
+
+func (n *PathRecursiveNode) Get(src, dst reflect.Value) error {
+	if n.child == nil {
+		return fmt.Errorf("failed to get by recursive path ..%s", n.selector)
+	}
+	var arr []interface{}
+	switch src.Type().Kind() {
+	case reflect.Map:
+		iter := src.MapRange()
+		for iter.Next() {
+			key, ok := iter.Key().Interface().(string)
+			if !ok {
+				return fmt.Errorf("invalid map key type %T", src.Type().Key())
+			}
+			child, found, err := n.Field(key)
+			if err != nil {
+				return err
+			}
+			if found {
+				var v interface{}
+				rv := reflect.ValueOf(&v)
+				_ = child.Get(iter.Value(), rv)
+				arr = append(arr, valueToSliceValue(v)...)
+			} else {
+				var v interface{}
+				rv := reflect.ValueOf(&v)
+				_ = n.Get(iter.Value(), rv)
+				if v != nil {
+					arr = append(arr, valueToSliceValue(v)...)
+				}
+			}
+		}
+		_ = AssignValue(reflect.ValueOf(arr), dst)
+		return nil
+	case reflect.Struct:
+		typ := src.Type()
+		for i := 0; i < typ.Len(); i++ {
+			tag := runtime.StructTagFromField(typ.Field(i))
+			child, found, err := n.Field(tag.Key)
+			if err != nil {
+				return err
+			}
+			if found {
+				var v interface{}
+				rv := reflect.ValueOf(&v)
+				_ = child.Get(src.Field(i), rv)
+				arr = append(arr, valueToSliceValue(v)...)
+			} else {
+				var v interface{}
+				rv := reflect.ValueOf(&v)
+				_ = n.Get(src.Field(i), rv)
+				if v != nil {
+					arr = append(arr, valueToSliceValue(v)...)
+				}
+			}
+		}
+		_ = AssignValue(reflect.ValueOf(arr), dst)
+		return nil
+	case reflect.Array, reflect.Slice:
+		for i := 0; i < src.Len(); i++ {
+			var v interface{}
+			rv := reflect.ValueOf(&v)
+			_ = n.Get(src.Index(i), rv)
+			if v != nil {
+				arr = append(arr, valueToSliceValue(v)...)
+			}
+		}
+		_ = AssignValue(reflect.ValueOf(arr), dst)
+		return nil
+	case reflect.Ptr:
+		return n.Get(src.Elem(), dst)
+	case reflect.Interface:
+		return n.Get(reflect.ValueOf(src.Interface()), dst)
+	}
+	return fmt.Errorf("failed to get %s value from %s", n.selector, src.Type())
+}
+
+func (n *PathRecursiveNode) String() string {
+	s := fmt.Sprintf("..%s", n.selector)
+	if n.child != nil {
+		s += n.child.String()
+	}
+	return s
+}

internal/decoder/ptr.go

@@ -0,0 +1,97 @@
+package decoder
+
+import (
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type ptrDecoder struct {
+	dec        Decoder
+	typ        *runtime.Type
+	structName string
+	fieldName  string
+}
+
+func newPtrDecoder(dec Decoder, typ *runtime.Type, structName, fieldName string) *ptrDecoder {
+	return &ptrDecoder{
+		dec:        dec,
+		typ:        typ,
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *ptrDecoder) contentDecoder() Decoder {
+	dec, ok := d.dec.(*ptrDecoder)
+	if !ok {
+		return d.dec
+	}
+	return dec.contentDecoder()
+}
+
+//nolint:golint
+//go:linkname unsafe_New reflect.unsafe_New
+func unsafe_New(*runtime.Type) unsafe.Pointer
+
+func UnsafeNew(t *runtime.Type) unsafe.Pointer {
+	return unsafe_New(t)
+}
+
+func (d *ptrDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	if s.skipWhiteSpace() == nul {
+		s.read()
+	}
+	if s.char() == 'n' {
+		if err := nullBytes(s); err != nil {
+			return err
+		}
+		*(*unsafe.Pointer)(p) = nil
+		return nil
+	}
+	var newptr unsafe.Pointer
+	if *(*unsafe.Pointer)(p) == nil {
+		newptr = unsafe_New(d.typ)
+		*(*unsafe.Pointer)(p) = newptr
+	} else {
+		newptr = *(*unsafe.Pointer)(p)
+	}
+	if err := d.dec.DecodeStream(s, depth, newptr); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (d *ptrDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	if buf[cursor] == 'n' {
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		if p != nil {
+			*(*unsafe.Pointer)(p) = nil
+		}
+		cursor += 4
+		return cursor, nil
+	}
+	var newptr unsafe.Pointer
+	if *(*unsafe.Pointer)(p) == nil {
+		newptr = unsafe_New(d.typ)
+		*(*unsafe.Pointer)(p) = newptr
+	} else {
+		newptr = *(*unsafe.Pointer)(p)
+	}
+	c, err := d.dec.Decode(ctx, cursor, depth, newptr)
+	if err != nil {
+		*(*unsafe.Pointer)(p) = nil
+		return 0, err
+	}
+	cursor = c
+	return cursor, nil
+}
+
+func (d *ptrDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: ptr decoder does not support decode path")
+}

internal/decoder/slice.go

@@ -0,0 +1,380 @@
+package decoder
+
+import (
+	"reflect"
+	"sync"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+var (
+	sliceType = runtime.Type2RType(
+		reflect.TypeOf((*sliceHeader)(nil)).Elem(),
+	)
+	nilSlice = unsafe.Pointer(&sliceHeader{})
+)
+
+type sliceDecoder struct {
+	elemType          *runtime.Type
+	isElemPointerType bool
+	valueDecoder      Decoder
+	size              uintptr
+	arrayPool         sync.Pool
+	structName        string
+	fieldName         string
+}
+
+// If use reflect.SliceHeader, data type is uintptr.
+// In this case, Go compiler cannot trace reference created by newArray().
+// So, define using unsafe.Pointer as data type
+type sliceHeader struct {
+	data unsafe.Pointer
+	len  int
+	cap  int
+}
+
+const (
+	defaultSliceCapacity = 2
+)
+
+func newSliceDecoder(dec Decoder, elemType *runtime.Type, size uintptr, structName, fieldName string) *sliceDecoder {
+	return &sliceDecoder{
+		valueDecoder:      dec,
+		elemType:          elemType,
+		isElemPointerType: elemType.Kind() == reflect.Ptr || elemType.Kind() == reflect.Map,
+		size:              size,
+		arrayPool: sync.Pool{
+			New: func() interface{} {
+				return &sliceHeader{
+					data: newArray(elemType, defaultSliceCapacity),
+					len:  0,
+					cap:  defaultSliceCapacity,
+				}
+			},
+		},
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *sliceDecoder) newSlice(src *sliceHeader) *sliceHeader {
+	slice := d.arrayPool.Get().(*sliceHeader)
+	if src.len > 0 {
+		// copy original elem
+		if slice.cap < src.cap {
+			data := newArray(d.elemType, src.cap)
+			slice = &sliceHeader{data: data, len: src.len, cap: src.cap}
+		} else {
+			slice.len = src.len
+		}
+		copySlice(d.elemType, *slice, *src)
+	} else {
+		slice.len = 0
+	}
+	return slice
+}
+
+func (d *sliceDecoder) releaseSlice(p *sliceHeader) {
+	d.arrayPool.Put(p)
+}
+
+//go:linkname copySlice reflect.typedslicecopy
+func copySlice(elemType *runtime.Type, dst, src sliceHeader) int
+
+//go:linkname newArray reflect.unsafe_NewArray
+func newArray(*runtime.Type, int) unsafe.Pointer
+
+//go:linkname typedmemmove reflect.typedmemmove
+func typedmemmove(t *runtime.Type, dst, src unsafe.Pointer)
+
+func (d *sliceDecoder) errNumber(offset int64) *errors.UnmarshalTypeError {
+	return &errors.UnmarshalTypeError{
+		Value:  "number",
+		Type:   reflect.SliceOf(runtime.RType2Type(d.elemType)),
+		Struct: d.structName,
+		Field:  d.fieldName,
+		Offset: offset,
+	}
+}
+
+func (d *sliceDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+	}
+
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			typedmemmove(sliceType, p, nilSlice)
+			return nil
+		case '[':
+			s.cursor++
+			if s.skipWhiteSpace() == ']' {
+				dst := (*sliceHeader)(p)
+				if dst.data == nil {
+					dst.data = newArray(d.elemType, 0)
+				} else {
+					dst.len = 0
+				}
+				s.cursor++
+				return nil
+			}
+			idx := 0
+			slice := d.newSlice((*sliceHeader)(p))
+			srcLen := slice.len
+			capacity := slice.cap
+			data := slice.data
+			for {
+				if capacity <= idx {
+					src := sliceHeader{data: data, len: idx, cap: capacity}
+					capacity *= 2
+					data = newArray(d.elemType, capacity)
+					dst := sliceHeader{data: data, len: idx, cap: capacity}
+					copySlice(d.elemType, dst, src)
+				}
+				ep := unsafe.Pointer(uintptr(data) + uintptr(idx)*d.size)
+
+				// if srcLen is greater than idx, keep the original reference
+				if srcLen <= idx {
+					if d.isElemPointerType {
+						**(**unsafe.Pointer)(unsafe.Pointer(&ep)) = nil // initialize elem pointer
+					} else {
+						// assign new element to the slice
+						typedmemmove(d.elemType, ep, unsafe_New(d.elemType))
+					}
+				}
+
+				if err := d.valueDecoder.DecodeStream(s, depth, ep); err != nil {
+					return err
+				}
+				s.skipWhiteSpace()
+			RETRY:
+				switch s.char() {
+				case ']':
+					slice.cap = capacity
+					slice.len = idx + 1
+					slice.data = data
+					dst := (*sliceHeader)(p)
+					dst.len = idx + 1
+					if dst.len > dst.cap {
+						dst.data = newArray(d.elemType, dst.len)
+						dst.cap = dst.len
+					}
+					copySlice(d.elemType, *dst, *slice)
+					d.releaseSlice(slice)
+					s.cursor++
+					return nil
+				case ',':
+					idx++
+				case nul:
+					if s.read() {
+						goto RETRY
+					}
+					slice.cap = capacity
+					slice.data = data
+					d.releaseSlice(slice)
+					goto ERROR
+				default:
+					slice.cap = capacity
+					slice.data = data
+					d.releaseSlice(slice)
+					goto ERROR
+				}
+				s.cursor++
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return d.errNumber(s.totalOffset())
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto ERROR
+		default:
+			goto ERROR
+		}
+	}
+ERROR:
+	return errors.ErrUnexpectedEndOfJSON("slice", s.totalOffset())
+}
+
+func (d *sliceDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return 0, err
+			}
+			cursor += 4
+			typedmemmove(sliceType, p, nilSlice)
+			return cursor, nil
+		case '[':
+			cursor++
+			cursor = skipWhiteSpace(buf, cursor)
+			if buf[cursor] == ']' {
+				dst := (*sliceHeader)(p)
+				if dst.data == nil {
+					dst.data = newArray(d.elemType, 0)
+				} else {
+					dst.len = 0
+				}
+				cursor++
+				return cursor, nil
+			}
+			idx := 0
+			slice := d.newSlice((*sliceHeader)(p))
+			srcLen := slice.len
+			capacity := slice.cap
+			data := slice.data
+			for {
+				if capacity <= idx {
+					src := sliceHeader{data: data, len: idx, cap: capacity}
+					capacity *= 2
+					data = newArray(d.elemType, capacity)
+					dst := sliceHeader{data: data, len: idx, cap: capacity}
+					copySlice(d.elemType, dst, src)
+				}
+				ep := unsafe.Pointer(uintptr(data) + uintptr(idx)*d.size)
+				// if srcLen is greater than idx, keep the original reference
+				if srcLen <= idx {
+					if d.isElemPointerType {
+						**(**unsafe.Pointer)(unsafe.Pointer(&ep)) = nil // initialize elem pointer
+					} else {
+						// assign new element to the slice
+						typedmemmove(d.elemType, ep, unsafe_New(d.elemType))
+					}
+				}
+				c, err := d.valueDecoder.Decode(ctx, cursor, depth, ep)
+				if err != nil {
+					return 0, err
+				}
+				cursor = c
+				cursor = skipWhiteSpace(buf, cursor)
+				switch buf[cursor] {
+				case ']':
+					slice.cap = capacity
+					slice.len = idx + 1
+					slice.data = data
+					dst := (*sliceHeader)(p)
+					dst.len = idx + 1
+					if dst.len > dst.cap {
+						dst.data = newArray(d.elemType, dst.len)
+						dst.cap = dst.len
+					}
+					copySlice(d.elemType, *dst, *slice)
+					d.releaseSlice(slice)
+					cursor++
+					return cursor, nil
+				case ',':
+					idx++
+				default:
+					slice.cap = capacity
+					slice.data = data
+					d.releaseSlice(slice)
+					return 0, errors.ErrInvalidCharacter(buf[cursor], "slice", cursor)
+				}
+				cursor++
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return 0, d.errNumber(cursor)
+		default:
+			return 0, errors.ErrUnexpectedEndOfJSON("slice", cursor)
+		}
+	}
+}
+
+func (d *sliceDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return nil, 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+
+	ret := [][]byte{}
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return [][]byte{nullbytes}, cursor, nil
+		case '[':
+			cursor++
+			cursor = skipWhiteSpace(buf, cursor)
+			if buf[cursor] == ']' {
+				cursor++
+				return ret, cursor, nil
+			}
+			idx := 0
+			for {
+				child, found, err := ctx.Option.Path.node.Index(idx)
+				if err != nil {
+					return nil, 0, err
+				}
+				if found {
+					if child != nil {
+						oldPath := ctx.Option.Path.node
+						ctx.Option.Path.node = child
+						paths, c, err := d.valueDecoder.DecodePath(ctx, cursor, depth)
+						if err != nil {
+							return nil, 0, err
+						}
+						ctx.Option.Path.node = oldPath
+						ret = append(ret, paths...)
+						cursor = c
+					} else {
+						start := cursor
+						end, err := skipValue(buf, cursor, depth)
+						if err != nil {
+							return nil, 0, err
+						}
+						ret = append(ret, buf[start:end])
+						cursor = end
+					}
+				} else {
+					c, err := skipValue(buf, cursor, depth)
+					if err != nil {
+						return nil, 0, err
+					}
+					cursor = c
+				}
+				cursor = skipWhiteSpace(buf, cursor)
+				switch buf[cursor] {
+				case ']':
+					cursor++
+					return ret, cursor, nil
+				case ',':
+					idx++
+				default:
+					return nil, 0, errors.ErrInvalidCharacter(buf[cursor], "slice", cursor)
+				}
+				cursor++
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return nil, 0, d.errNumber(cursor)
+		default:
+			return nil, 0, errors.ErrUnexpectedEndOfJSON("slice", cursor)
+		}
+	}
+}

internal/decoder/stream.go

@@ -0,0 +1,556 @@
+package decoder
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"strconv"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+const (
+	initBufSize = 512
+)
+
+type Stream struct {
+	buf                   []byte
+	bufSize               int64
+	length                int64
+	r                     io.Reader
+	offset                int64
+	cursor                int64
+	filledBuffer          bool
+	allRead               bool
+	UseNumber             bool
+	DisallowUnknownFields bool
+	Option                *Option
+}
+
+func NewStream(r io.Reader) *Stream {
+	return &Stream{
+		r:       r,
+		bufSize: initBufSize,
+		buf:     make([]byte, initBufSize),
+		Option:  &Option{},
+	}
+}
+
+func (s *Stream) TotalOffset() int64 {
+	return s.totalOffset()
+}
+
+func (s *Stream) Buffered() io.Reader {
+	buflen := int64(len(s.buf))
+	for i := s.cursor; i < buflen; i++ {
+		if s.buf[i] == nul {
+			return bytes.NewReader(s.buf[s.cursor:i])
+		}
+	}
+	return bytes.NewReader(s.buf[s.cursor:])
+}
+
+func (s *Stream) PrepareForDecode() error {
+	for {
+		switch s.char() {
+		case ' ', '\t', '\r', '\n':
+			s.cursor++
+			continue
+		case ',', ':':
+			s.cursor++
+			return nil
+		case nul:
+			if s.read() {
+				continue
+			}
+			return io.EOF
+		}
+		break
+	}
+	return nil
+}
+
+func (s *Stream) totalOffset() int64 {
+	return s.offset + s.cursor
+}
+
+func (s *Stream) char() byte {
+	return s.buf[s.cursor]
+}
+
+func (s *Stream) equalChar(c byte) bool {
+	cur := s.buf[s.cursor]
+	if cur == nul {
+		s.read()
+		cur = s.buf[s.cursor]
+	}
+	return cur == c
+}
+
+func (s *Stream) stat() ([]byte, int64, unsafe.Pointer) {
+	return s.buf, s.cursor, (*sliceHeader)(unsafe.Pointer(&s.buf)).data
+}
+
+func (s *Stream) bufptr() unsafe.Pointer {
+	return (*sliceHeader)(unsafe.Pointer(&s.buf)).data
+}
+
+func (s *Stream) statForRetry() ([]byte, int64, unsafe.Pointer) {
+	s.cursor-- // for retry ( because caller progress cursor position in each loop )
+	return s.buf, s.cursor, (*sliceHeader)(unsafe.Pointer(&s.buf)).data
+}
+
+func (s *Stream) Reset() {
+	s.reset()
+	s.bufSize = int64(len(s.buf))
+}
+
+func (s *Stream) More() bool {
+	for {
+		switch s.char() {
+		case ' ', '\n', '\r', '\t':
+			s.cursor++
+			continue
+		case '}', ']':
+			return false
+		case nul:
+			if s.read() {
+				continue
+			}
+			return false
+		}
+		break
+	}
+	return true
+}
+
+func (s *Stream) Token() (interface{}, error) {
+	for {
+		c := s.char()
+		switch c {
+		case ' ', '\n', '\r', '\t':
+			s.cursor++
+		case '{', '[', ']', '}':
+			s.cursor++
+			return json.Delim(c), nil
+		case ',', ':':
+			s.cursor++
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			bytes := floatBytes(s)
+			str := *(*string)(unsafe.Pointer(&bytes))
+			if s.UseNumber {
+				return json.Number(str), nil
+			}
+			f64, err := strconv.ParseFloat(str, 64)
+			if err != nil {
+				return nil, err
+			}
+			return f64, nil
+		case '"':
+			bytes, err := stringBytes(s)
+			if err != nil {
+				return nil, err
+			}
+			return string(bytes), nil
+		case 't':
+			if err := trueBytes(s); err != nil {
+				return nil, err
+			}
+			return true, nil
+		case 'f':
+			if err := falseBytes(s); err != nil {
+				return nil, err
+			}
+			return false, nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case nul:
+			if s.read() {
+				continue
+			}
+			goto END
+		default:
+			return nil, errors.ErrInvalidCharacter(s.char(), "token", s.totalOffset())
+		}
+	}
+END:
+	return nil, io.EOF
+}
+
+func (s *Stream) reset() {
+	s.offset += s.cursor
+	s.buf = s.buf[s.cursor:]
+	s.length -= s.cursor
+	s.cursor = 0
+}
+
+func (s *Stream) readBuf() []byte {
+	if s.filledBuffer {
+		s.bufSize *= 2
+		remainBuf := s.buf
+		s.buf = make([]byte, s.bufSize)
+		copy(s.buf, remainBuf)
+	}
+	remainLen := s.length - s.cursor
+	remainNotNulCharNum := int64(0)
+	for i := int64(0); i < remainLen; i++ {
+		if s.buf[s.cursor+i] == nul {
+			break
+		}
+		remainNotNulCharNum++
+	}
+	s.length = s.cursor + remainNotNulCharNum
+	return s.buf[s.cursor+remainNotNulCharNum:]
+}
+
+func (s *Stream) read() bool {
+	if s.allRead {
+		return false
+	}
+	buf := s.readBuf()
+	last := len(buf) - 1
+	buf[last] = nul
+	n, err := s.r.Read(buf[:last])
+	s.length += int64(n)
+	if n == last {
+		s.filledBuffer = true
+	} else {
+		s.filledBuffer = false
+	}
+	if err == io.EOF {
+		s.allRead = true
+	} else if err != nil {
+		return false
+	}
+	return true
+}
+
+func (s *Stream) skipWhiteSpace() byte {
+	p := s.bufptr()
+LOOP:
+	c := char(p, s.cursor)
+	switch c {
+	case ' ', '\n', '\t', '\r':
+		s.cursor++
+		goto LOOP
+	case nul:
+		if s.read() {
+			p = s.bufptr()
+			goto LOOP
+		}
+	}
+	return c
+}
+
+func (s *Stream) skipObject(depth int64) error {
+	braceCount := 1
+	_, cursor, p := s.stat()
+	for {
+		switch char(p, cursor) {
+		case '{':
+			braceCount++
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+			}
+		case '}':
+			braceCount--
+			depth--
+			if braceCount == 0 {
+				s.cursor = cursor + 1
+				return nil
+			}
+		case '[':
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+			}
+		case ']':
+			depth--
+		case '"':
+			for {
+				cursor++
+				switch char(p, cursor) {
+				case '\\':
+					cursor++
+					if char(p, cursor) == nul {
+						s.cursor = cursor
+						if s.read() {
+							_, cursor, p = s.stat()
+							continue
+						}
+						return errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+					}
+				case '"':
+					goto SWITCH_OUT
+				case nul:
+					s.cursor = cursor
+					if s.read() {
+						_, cursor, p = s.statForRetry()
+						continue
+					}
+					return errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+				}
+			}
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			return errors.ErrUnexpectedEndOfJSON("object of object", cursor)
+		}
+	SWITCH_OUT:
+		cursor++
+	}
+}
+
+func (s *Stream) skipArray(depth int64) error {
+	bracketCount := 1
+	_, cursor, p := s.stat()
+	for {
+		switch char(p, cursor) {
+		case '[':
+			bracketCount++
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+			}
+		case ']':
+			bracketCount--
+			depth--
+			if bracketCount == 0 {
+				s.cursor = cursor + 1
+				return nil
+			}
+		case '{':
+			depth++
+			if depth > maxDecodeNestingDepth {
+				return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+			}
+		case '}':
+			depth--
+		case '"':
+			for {
+				cursor++
+				switch char(p, cursor) {
+				case '\\':
+					cursor++
+					if char(p, cursor) == nul {
+						s.cursor = cursor
+						if s.read() {
+							_, cursor, p = s.stat()
+							continue
+						}
+						return errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+					}
+				case '"':
+					goto SWITCH_OUT
+				case nul:
+					s.cursor = cursor
+					if s.read() {
+						_, cursor, p = s.statForRetry()
+						continue
+					}
+					return errors.ErrUnexpectedEndOfJSON("string of object", cursor)
+				}
+			}
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			return errors.ErrUnexpectedEndOfJSON("array of object", cursor)
+		}
+	SWITCH_OUT:
+		cursor++
+	}
+}
+
+func (s *Stream) skipValue(depth int64) error {
+	_, cursor, p := s.stat()
+	for {
+		switch char(p, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			return errors.ErrUnexpectedEndOfJSON("value of object", s.totalOffset())
+		case '{':
+			s.cursor = cursor + 1
+			return s.skipObject(depth + 1)
+		case '[':
+			s.cursor = cursor + 1
+			return s.skipArray(depth + 1)
+		case '"':
+			for {
+				cursor++
+				switch char(p, cursor) {
+				case '\\':
+					cursor++
+					if char(p, cursor) == nul {
+						s.cursor = cursor
+						if s.read() {
+							_, cursor, p = s.stat()
+							continue
+						}
+						return errors.ErrUnexpectedEndOfJSON("value of string", s.totalOffset())
+					}
+				case '"':
+					s.cursor = cursor + 1
+					return nil
+				case nul:
+					s.cursor = cursor
+					if s.read() {
+						_, cursor, p = s.statForRetry()
+						continue
+					}
+					return errors.ErrUnexpectedEndOfJSON("value of string", s.totalOffset())
+				}
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			for {
+				cursor++
+				c := char(p, cursor)
+				if floatTable[c] {
+					continue
+				} else if c == nul {
+					if s.read() {
+						_, cursor, p = s.stat()
+						continue
+					}
+				}
+				s.cursor = cursor
+				return nil
+			}
+		case 't':
+			s.cursor = cursor
+			if err := trueBytes(s); err != nil {
+				return err
+			}
+			return nil
+		case 'f':
+			s.cursor = cursor
+			if err := falseBytes(s); err != nil {
+				return err
+			}
+			return nil
+		case 'n':
+			s.cursor = cursor
+			if err := nullBytes(s); err != nil {
+				return err
+			}
+			return nil
+		}
+		cursor++
+	}
+}
+
+func nullBytes(s *Stream) error {
+	// current cursor's character is 'n'
+	s.cursor++
+	if s.char() != 'u' {
+		if err := retryReadNull(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'l' {
+		if err := retryReadNull(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'l' {
+		if err := retryReadNull(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	return nil
+}
+
+func retryReadNull(s *Stream) error {
+	if s.char() == nul && s.read() {
+		return nil
+	}
+	return errors.ErrInvalidCharacter(s.char(), "null", s.totalOffset())
+}
+
+func trueBytes(s *Stream) error {
+	// current cursor's character is 't'
+	s.cursor++
+	if s.char() != 'r' {
+		if err := retryReadTrue(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'u' {
+		if err := retryReadTrue(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'e' {
+		if err := retryReadTrue(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	return nil
+}
+
+func retryReadTrue(s *Stream) error {
+	if s.char() == nul && s.read() {
+		return nil
+	}
+	return errors.ErrInvalidCharacter(s.char(), "bool(true)", s.totalOffset())
+}
+
+func falseBytes(s *Stream) error {
+	// current cursor's character is 'f'
+	s.cursor++
+	if s.char() != 'a' {
+		if err := retryReadFalse(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'l' {
+		if err := retryReadFalse(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 's' {
+		if err := retryReadFalse(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	if s.char() != 'e' {
+		if err := retryReadFalse(s); err != nil {
+			return err
+		}
+	}
+	s.cursor++
+	return nil
+}
+
+func retryReadFalse(s *Stream) error {
+	if s.char() == nul && s.read() {
+		return nil
+	}
+	return errors.ErrInvalidCharacter(s.char(), "bool(false)", s.totalOffset())
+}

internal/decoder/string.go

@@ -0,0 +1,452 @@
+package decoder
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"unicode"
+	"unicode/utf16"
+	"unicode/utf8"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type stringDecoder struct {
+	structName string
+	fieldName  string
+}
+
+func newStringDecoder(structName, fieldName string) *stringDecoder {
+	return &stringDecoder{
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *stringDecoder) errUnmarshalType(typeName string, offset int64) *errors.UnmarshalTypeError {
+	return &errors.UnmarshalTypeError{
+		Value:  typeName,
+		Type:   reflect.TypeOf(""),
+		Offset: offset,
+		Struct: d.structName,
+		Field:  d.fieldName,
+	}
+}
+
+func (d *stringDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		return nil
+	}
+	**(**string)(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&bytes))
+	s.reset()
+	return nil
+}
+
+func (d *stringDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		return c, nil
+	}
+	cursor = c
+	**(**string)(unsafe.Pointer(&p)) = *(*string)(unsafe.Pointer(&bytes))
+	return cursor, nil
+}
+
+func (d *stringDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return nil, 0, err
+	}
+	if bytes == nil {
+		return [][]byte{nullbytes}, c, nil
+	}
+	return [][]byte{bytes}, c, nil
+}
+
+var (
+	hexToInt = [256]int{
+		'0': 0,
+		'1': 1,
+		'2': 2,
+		'3': 3,
+		'4': 4,
+		'5': 5,
+		'6': 6,
+		'7': 7,
+		'8': 8,
+		'9': 9,
+		'A': 10,
+		'B': 11,
+		'C': 12,
+		'D': 13,
+		'E': 14,
+		'F': 15,
+		'a': 10,
+		'b': 11,
+		'c': 12,
+		'd': 13,
+		'e': 14,
+		'f': 15,
+	}
+)
+
+func unicodeToRune(code []byte) rune {
+	var r rune
+	for i := 0; i < len(code); i++ {
+		r = r*16 + rune(hexToInt[code[i]])
+	}
+	return r
+}
+
+func readAtLeast(s *Stream, n int64, p *unsafe.Pointer) bool {
+	for s.cursor+n >= s.length {
+		if !s.read() {
+			return false
+		}
+		*p = s.bufptr()
+	}
+	return true
+}
+
+func decodeUnicodeRune(s *Stream, p unsafe.Pointer) (rune, int64, unsafe.Pointer, error) {
+	const defaultOffset = 5
+	const surrogateOffset = 11
+
+	if !readAtLeast(s, defaultOffset, &p) {
+		return rune(0), 0, nil, errors.ErrInvalidCharacter(s.char(), "escaped string", s.totalOffset())
+	}
+
+	r := unicodeToRune(s.buf[s.cursor+1 : s.cursor+defaultOffset])
+	if utf16.IsSurrogate(r) {
+		if !readAtLeast(s, surrogateOffset, &p) {
+			return unicode.ReplacementChar, defaultOffset, p, nil
+		}
+		if s.buf[s.cursor+defaultOffset] != '\\' || s.buf[s.cursor+defaultOffset+1] != 'u' {
+			return unicode.ReplacementChar, defaultOffset, p, nil
+		}
+		r2 := unicodeToRune(s.buf[s.cursor+defaultOffset+2 : s.cursor+surrogateOffset])
+		if r := utf16.DecodeRune(r, r2); r != unicode.ReplacementChar {
+			return r, surrogateOffset, p, nil
+		}
+	}
+	return r, defaultOffset, p, nil
+}
+
+func decodeUnicode(s *Stream, p unsafe.Pointer) (unsafe.Pointer, error) {
+	const backSlashAndULen = 2 // length of \u
+
+	r, offset, pp, err := decodeUnicodeRune(s, p)
+	if err != nil {
+		return nil, err
+	}
+	unicode := []byte(string(r))
+	unicodeLen := int64(len(unicode))
+	s.buf = append(append(s.buf[:s.cursor-1], unicode...), s.buf[s.cursor+offset:]...)
+	unicodeOrgLen := offset - 1
+	s.length = s.length - (backSlashAndULen + (unicodeOrgLen - unicodeLen))
+	s.cursor = s.cursor - backSlashAndULen + unicodeLen
+	return pp, nil
+}
+
+func decodeEscapeString(s *Stream, p unsafe.Pointer) (unsafe.Pointer, error) {
+	s.cursor++
+RETRY:
+	switch s.buf[s.cursor] {
+	case '"':
+		s.buf[s.cursor] = '"'
+	case '\\':
+		s.buf[s.cursor] = '\\'
+	case '/':
+		s.buf[s.cursor] = '/'
+	case 'b':
+		s.buf[s.cursor] = '\b'
+	case 'f':
+		s.buf[s.cursor] = '\f'
+	case 'n':
+		s.buf[s.cursor] = '\n'
+	case 'r':
+		s.buf[s.cursor] = '\r'
+	case 't':
+		s.buf[s.cursor] = '\t'
+	case 'u':
+		return decodeUnicode(s, p)
+	case nul:
+		if !s.read() {
+			return nil, errors.ErrInvalidCharacter(s.char(), "escaped string", s.totalOffset())
+		}
+		p = s.bufptr()
+		goto RETRY
+	default:
+		return nil, errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+	}
+	s.buf = append(s.buf[:s.cursor-1], s.buf[s.cursor:]...)
+	s.length--
+	s.cursor--
+	p = s.bufptr()
+	return p, nil
+}
+
+var (
+	runeErrBytes    = []byte(string(utf8.RuneError))
+	runeErrBytesLen = int64(len(runeErrBytes))
+)
+
+func stringBytes(s *Stream) ([]byte, error) {
+	_, cursor, p := s.stat()
+	cursor++ // skip double quote char
+	start := cursor
+	for {
+		switch char(p, cursor) {
+		case '\\':
+			s.cursor = cursor
+			pp, err := decodeEscapeString(s, p)
+			if err != nil {
+				return nil, err
+			}
+			p = pp
+			cursor = s.cursor
+		case '"':
+			literal := s.buf[start:cursor]
+			cursor++
+			s.cursor = cursor
+			return literal, nil
+		case
+			// 0x00 is nul, 0x5c is '\\', 0x22 is '"' .
+			0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, // 0x00-0x0F
+			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, // 0x10-0x1F
+			0x20, 0x21 /*0x22,*/, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, // 0x20-0x2F
+			0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, // 0x30-0x3F
+			0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, // 0x40-0x4F
+			0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B /*0x5C,*/, 0x5D, 0x5E, 0x5F, // 0x50-0x5F
+			0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, // 0x60-0x6F
+			0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F: // 0x70-0x7F
+			// character is ASCII. skip to next char
+		case
+			0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, // 0x80-0x8F
+			0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, // 0x90-0x9F
+			0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, // 0xA0-0xAF
+			0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF, // 0xB0-0xBF
+			0xC0, 0xC1, // 0xC0-0xC1
+			0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF: // 0xF5-0xFE
+			// character is invalid
+			s.buf = append(append(append([]byte{}, s.buf[:cursor]...), runeErrBytes...), s.buf[cursor+1:]...)
+			_, _, p = s.stat()
+			cursor += runeErrBytesLen
+			s.length += runeErrBytesLen
+			continue
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			goto ERROR
+		case 0xEF:
+			// RuneError is {0xEF, 0xBF, 0xBD}
+			if s.buf[cursor+1] == 0xBF && s.buf[cursor+2] == 0xBD {
+				// found RuneError: skip
+				cursor += 2
+				break
+			}
+			fallthrough
+		default:
+			// multi bytes character
+			if !utf8.FullRune(s.buf[cursor : len(s.buf)-1]) {
+				s.cursor = cursor
+				if s.read() {
+					_, cursor, p = s.stat()
+					continue
+				}
+				goto ERROR
+			}
+			r, size := utf8.DecodeRune(s.buf[cursor:])
+			if r == utf8.RuneError {
+				s.buf = append(append(append([]byte{}, s.buf[:cursor]...), runeErrBytes...), s.buf[cursor+1:]...)
+				cursor += runeErrBytesLen
+				s.length += runeErrBytesLen
+				_, _, p = s.stat()
+			} else {
+				cursor += int64(size)
+			}
+			continue
+		}
+		cursor++
+	}
+ERROR:
+	return nil, errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+}
+
+func (d *stringDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case '[':
+			return nil, d.errUnmarshalType("array", s.totalOffset())
+		case '{':
+			return nil, d.errUnmarshalType("object", s.totalOffset())
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return nil, d.errUnmarshalType("number", s.totalOffset())
+		case '"':
+			return stringBytes(s)
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case nul:
+			if s.read() {
+				continue
+			}
+		}
+		break
+	}
+	return nil, errors.ErrInvalidBeginningOfValue(s.char(), s.totalOffset())
+}
+
+func (d *stringDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+		case '[':
+			return nil, 0, d.errUnmarshalType("array", cursor)
+		case '{':
+			return nil, 0, d.errUnmarshalType("object", cursor)
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return nil, 0, d.errUnmarshalType("number", cursor)
+		case '"':
+			cursor++
+			start := cursor
+			b := (*sliceHeader)(unsafe.Pointer(&buf)).data
+			escaped := 0
+			for {
+				switch char(b, cursor) {
+				case '\\':
+					escaped++
+					cursor++
+					switch char(b, cursor) {
+					case '"', '\\', '/', 'b', 'f', 'n', 'r', 't':
+						cursor++
+					case 'u':
+						buflen := int64(len(buf))
+						if cursor+5 >= buflen {
+							return nil, 0, errors.ErrUnexpectedEndOfJSON("escaped string", cursor)
+						}
+						for i := int64(1); i <= 4; i++ {
+							c := char(b, cursor+i)
+							if !(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')) {
+								return nil, 0, errors.ErrSyntax(fmt.Sprintf("json: invalid character %c in \\u hexadecimal character escape", c), cursor+i)
+							}
+						}
+						cursor += 5
+					default:
+						return nil, 0, errors.ErrUnexpectedEndOfJSON("escaped string", cursor)
+					}
+					continue
+				case '"':
+					literal := buf[start:cursor]
+					if escaped > 0 {
+						literal = literal[:unescapeString(literal)]
+					}
+					cursor++
+					return literal, cursor, nil
+				case nul:
+					return nil, 0, errors.ErrUnexpectedEndOfJSON("string", cursor)
+				}
+				cursor++
+			}
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return nil, cursor, nil
+		default:
+			return nil, 0, errors.ErrInvalidBeginningOfValue(buf[cursor], cursor)
+		}
+	}
+}
+
+var unescapeMap = [256]byte{
+	'"':  '"',
+	'\\': '\\',
+	'/':  '/',
+	'b':  '\b',
+	'f':  '\f',
+	'n':  '\n',
+	'r':  '\r',
+	't':  '\t',
+}
+
+func unsafeAdd(ptr unsafe.Pointer, offset int) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(ptr) + uintptr(offset))
+}
+
+func unescapeString(buf []byte) int {
+	p := (*sliceHeader)(unsafe.Pointer(&buf)).data
+	end := unsafeAdd(p, len(buf))
+	src := unsafeAdd(p, bytes.IndexByte(buf, '\\'))
+	dst := src
+	for src != end {
+		c := char(src, 0)
+		if c == '\\' {
+			escapeChar := char(src, 1)
+			if escapeChar != 'u' {
+				*(*byte)(dst) = unescapeMap[escapeChar]
+				src = unsafeAdd(src, 2)
+				dst = unsafeAdd(dst, 1)
+			} else {
+				v1 := hexToInt[char(src, 2)]
+				v2 := hexToInt[char(src, 3)]
+				v3 := hexToInt[char(src, 4)]
+				v4 := hexToInt[char(src, 5)]
+				code := rune((v1 << 12) | (v2 << 8) | (v3 << 4) | v4)
+				if code >= 0xd800 && code < 0xdc00 && uintptr(unsafeAdd(src, 11)) < uintptr(end) {
+					if char(src, 6) == '\\' && char(src, 7) == 'u' {
+						v1 := hexToInt[char(src, 8)]
+						v2 := hexToInt[char(src, 9)]
+						v3 := hexToInt[char(src, 10)]
+						v4 := hexToInt[char(src, 11)]
+						lo := rune((v1 << 12) | (v2 << 8) | (v3 << 4) | v4)
+						if lo >= 0xdc00 && lo < 0xe000 {
+							code = (code-0xd800)<<10 | (lo - 0xdc00) + 0x10000
+							src = unsafeAdd(src, 6)
+						}
+					}
+				}
+				var b [utf8.UTFMax]byte
+				n := utf8.EncodeRune(b[:], code)
+				switch n {
+				case 4:
+					*(*byte)(unsafeAdd(dst, 3)) = b[3]
+					fallthrough
+				case 3:
+					*(*byte)(unsafeAdd(dst, 2)) = b[2]
+					fallthrough
+				case 2:
+					*(*byte)(unsafeAdd(dst, 1)) = b[1]
+					fallthrough
+				case 1:
+					*(*byte)(unsafeAdd(dst, 0)) = b[0]
+				}
+				src = unsafeAdd(src, 6)
+				dst = unsafeAdd(dst, n)
+			}
+		} else {
+			*(*byte)(dst) = c
+			src = unsafeAdd(src, 1)
+			dst = unsafeAdd(dst, 1)
+		}
+	}
+	return int(uintptr(dst) - uintptr(p))
+}

internal/decoder/struct.go

@@ -0,0 +1,845 @@
+package decoder
+
+import (
+	"fmt"
+	"math"
+	"math/bits"
+	"sort"
+	"strings"
+	"unicode"
+	"unicode/utf16"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+type structFieldSet struct {
+	dec         Decoder
+	offset      uintptr
+	isTaggedKey bool
+	fieldIdx    int
+	key         string
+	keyLen      int64
+	err         error
+}
+
+type structDecoder struct {
+	fieldMap           map[string]*structFieldSet
+	fieldUniqueNameNum int
+	stringDecoder      *stringDecoder
+	structName         string
+	fieldName          string
+	isTriedOptimize    bool
+	keyBitmapUint8     [][256]uint8
+	keyBitmapUint16    [][256]uint16
+	sortedFieldSets    []*structFieldSet
+	keyDecoder         func(*structDecoder, []byte, int64) (int64, *structFieldSet, error)
+	keyStreamDecoder   func(*structDecoder, *Stream) (*structFieldSet, string, error)
+}
+
+var (
+	largeToSmallTable [256]byte
+)
+
+func init() {
+	for i := 0; i < 256; i++ {
+		c := i
+		if 'A' <= c && c <= 'Z' {
+			c += 'a' - 'A'
+		}
+		largeToSmallTable[i] = byte(c)
+	}
+}
+
+func toASCIILower(s string) string {
+	b := []byte(s)
+	for i := range b {
+		b[i] = largeToSmallTable[b[i]]
+	}
+	return string(b)
+}
+
+func newStructDecoder(structName, fieldName string, fieldMap map[string]*structFieldSet) *structDecoder {
+	return &structDecoder{
+		fieldMap:         fieldMap,
+		stringDecoder:    newStringDecoder(structName, fieldName),
+		structName:       structName,
+		fieldName:        fieldName,
+		keyDecoder:       decodeKey,
+		keyStreamDecoder: decodeKeyStream,
+	}
+}
+
+const (
+	allowOptimizeMaxKeyLen   = 64
+	allowOptimizeMaxFieldLen = 16
+)
+
+func (d *structDecoder) tryOptimize() {
+	fieldUniqueNameMap := map[string]int{}
+	fieldIdx := -1
+	for k, v := range d.fieldMap {
+		lower := strings.ToLower(k)
+		idx, exists := fieldUniqueNameMap[lower]
+		if exists {
+			v.fieldIdx = idx
+		} else {
+			fieldIdx++
+			v.fieldIdx = fieldIdx
+		}
+		fieldUniqueNameMap[lower] = fieldIdx
+	}
+	d.fieldUniqueNameNum = len(fieldUniqueNameMap)
+
+	if d.isTriedOptimize {
+		return
+	}
+	fieldMap := map[string]*structFieldSet{}
+	conflicted := map[string]struct{}{}
+	for k, v := range d.fieldMap {
+		key := strings.ToLower(k)
+		if key != k {
+			if key != toASCIILower(k) {
+				d.isTriedOptimize = true
+				return
+			}
+			// already exists same key (e.g. Hello and HELLO has same lower case key
+			if _, exists := conflicted[key]; exists {
+				d.isTriedOptimize = true
+				return
+			}
+			conflicted[key] = struct{}{}
+		}
+		if field, exists := fieldMap[key]; exists {
+			if field != v {
+				d.isTriedOptimize = true
+				return
+			}
+		}
+		fieldMap[key] = v
+	}
+
+	if len(fieldMap) > allowOptimizeMaxFieldLen {
+		d.isTriedOptimize = true
+		return
+	}
+
+	var maxKeyLen int
+	sortedKeys := []string{}
+	for key := range fieldMap {
+		keyLen := len(key)
+		if keyLen > allowOptimizeMaxKeyLen {
+			d.isTriedOptimize = true
+			return
+		}
+		if maxKeyLen < keyLen {
+			maxKeyLen = keyLen
+		}
+		sortedKeys = append(sortedKeys, key)
+	}
+	sort.Strings(sortedKeys)
+
+	// By allocating one extra capacity than `maxKeyLen`,
+	// it is possible to avoid the process of comparing the index of the key with the length of the bitmap each time.
+	bitmapLen := maxKeyLen + 1
+	if len(sortedKeys) <= 8 {
+		keyBitmap := make([][256]uint8, bitmapLen)
+		for i, key := range sortedKeys {
+			for j := 0; j < len(key); j++ {
+				c := key[j]
+				keyBitmap[j][c] |= (1 << uint(i))
+			}
+			d.sortedFieldSets = append(d.sortedFieldSets, fieldMap[key])
+		}
+		d.keyBitmapUint8 = keyBitmap
+		d.keyDecoder = decodeKeyByBitmapUint8
+		d.keyStreamDecoder = decodeKeyByBitmapUint8Stream
+	} else {
+		keyBitmap := make([][256]uint16, bitmapLen)
+		for i, key := range sortedKeys {
+			for j := 0; j < len(key); j++ {
+				c := key[j]
+				keyBitmap[j][c] |= (1 << uint(i))
+			}
+			d.sortedFieldSets = append(d.sortedFieldSets, fieldMap[key])
+		}
+		d.keyBitmapUint16 = keyBitmap
+		d.keyDecoder = decodeKeyByBitmapUint16
+		d.keyStreamDecoder = decodeKeyByBitmapUint16Stream
+	}
+}
+
+// decode from '\uXXXX'
+func decodeKeyCharByUnicodeRune(buf []byte, cursor int64) ([]byte, int64, error) {
+	const defaultOffset = 4
+	const surrogateOffset = 6
+
+	if cursor+defaultOffset >= int64(len(buf)) {
+		return nil, 0, errors.ErrUnexpectedEndOfJSON("escaped string", cursor)
+	}
+
+	r := unicodeToRune(buf[cursor : cursor+defaultOffset])
+	if utf16.IsSurrogate(r) {
+		cursor += defaultOffset
+		if cursor+surrogateOffset >= int64(len(buf)) || buf[cursor] != '\\' || buf[cursor+1] != 'u' {
+			return []byte(string(unicode.ReplacementChar)), cursor + defaultOffset - 1, nil
+		}
+		cursor += 2
+		r2 := unicodeToRune(buf[cursor : cursor+defaultOffset])
+		if r := utf16.DecodeRune(r, r2); r != unicode.ReplacementChar {
+			return []byte(string(r)), cursor + defaultOffset - 1, nil
+		}
+	}
+	return []byte(string(r)), cursor + defaultOffset - 1, nil
+}
+
+func decodeKeyCharByEscapedChar(buf []byte, cursor int64) ([]byte, int64, error) {
+	c := buf[cursor]
+	cursor++
+	switch c {
+	case '"':
+		return []byte{'"'}, cursor, nil
+	case '\\':
+		return []byte{'\\'}, cursor, nil
+	case '/':
+		return []byte{'/'}, cursor, nil
+	case 'b':
+		return []byte{'\b'}, cursor, nil
+	case 'f':
+		return []byte{'\f'}, cursor, nil
+	case 'n':
+		return []byte{'\n'}, cursor, nil
+	case 'r':
+		return []byte{'\r'}, cursor, nil
+	case 't':
+		return []byte{'\t'}, cursor, nil
+	case 'u':
+		return decodeKeyCharByUnicodeRune(buf, cursor)
+	}
+	return nil, cursor, nil
+}
+
+func decodeKeyByBitmapUint8(d *structDecoder, buf []byte, cursor int64) (int64, *structFieldSet, error) {
+	var (
+		curBit uint8 = math.MaxUint8
+	)
+	b := (*sliceHeader)(unsafe.Pointer(&buf)).data
+	for {
+		switch char(b, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+		case '"':
+			cursor++
+			c := char(b, cursor)
+			switch c {
+			case '"':
+				cursor++
+				return cursor, nil, nil
+			case nul:
+				return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+			}
+			keyIdx := 0
+			bitmap := d.keyBitmapUint8
+			start := cursor
+			for {
+				c := char(b, cursor)
+				switch c {
+				case '"':
+					fieldSetIndex := bits.TrailingZeros8(curBit)
+					field := d.sortedFieldSets[fieldSetIndex]
+					keyLen := cursor - start
+					cursor++
+					if keyLen < field.keyLen {
+						// early match
+						return cursor, nil, nil
+					}
+					return cursor, field, nil
+				case nul:
+					return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+				case '\\':
+					cursor++
+					chars, nextCursor, err := decodeKeyCharByEscapedChar(buf, cursor)
+					if err != nil {
+						return 0, nil, err
+					}
+					for _, c := range chars {
+						curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+						if curBit == 0 {
+							return decodeKeyNotFound(b, cursor)
+						}
+						keyIdx++
+					}
+					cursor = nextCursor
+				default:
+					curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+					if curBit == 0 {
+						return decodeKeyNotFound(b, cursor)
+					}
+					keyIdx++
+				}
+				cursor++
+			}
+		default:
+			return cursor, nil, errors.ErrInvalidBeginningOfValue(char(b, cursor), cursor)
+		}
+	}
+}
+
+func decodeKeyByBitmapUint16(d *structDecoder, buf []byte, cursor int64) (int64, *structFieldSet, error) {
+	var (
+		curBit uint16 = math.MaxUint16
+	)
+	b := (*sliceHeader)(unsafe.Pointer(&buf)).data
+	for {
+		switch char(b, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+		case '"':
+			cursor++
+			c := char(b, cursor)
+			switch c {
+			case '"':
+				cursor++
+				return cursor, nil, nil
+			case nul:
+				return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+			}
+			keyIdx := 0
+			bitmap := d.keyBitmapUint16
+			start := cursor
+			for {
+				c := char(b, cursor)
+				switch c {
+				case '"':
+					fieldSetIndex := bits.TrailingZeros16(curBit)
+					field := d.sortedFieldSets[fieldSetIndex]
+					keyLen := cursor - start
+					cursor++
+					if keyLen < field.keyLen {
+						// early match
+						return cursor, nil, nil
+					}
+					return cursor, field, nil
+				case nul:
+					return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+				case '\\':
+					cursor++
+					chars, nextCursor, err := decodeKeyCharByEscapedChar(buf, cursor)
+					if err != nil {
+						return 0, nil, err
+					}
+					for _, c := range chars {
+						curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+						if curBit == 0 {
+							return decodeKeyNotFound(b, cursor)
+						}
+						keyIdx++
+					}
+					cursor = nextCursor
+				default:
+					curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+					if curBit == 0 {
+						return decodeKeyNotFound(b, cursor)
+					}
+					keyIdx++
+				}
+				cursor++
+			}
+		default:
+			return cursor, nil, errors.ErrInvalidBeginningOfValue(char(b, cursor), cursor)
+		}
+	}
+}
+
+func decodeKeyNotFound(b unsafe.Pointer, cursor int64) (int64, *structFieldSet, error) {
+	for {
+		cursor++
+		switch char(b, cursor) {
+		case '"':
+			cursor++
+			return cursor, nil, nil
+		case '\\':
+			cursor++
+			if char(b, cursor) == nul {
+				return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+			}
+		case nul:
+			return 0, nil, errors.ErrUnexpectedEndOfJSON("string", cursor)
+		}
+	}
+}
+
+func decodeKey(d *structDecoder, buf []byte, cursor int64) (int64, *structFieldSet, error) {
+	key, c, err := d.stringDecoder.decodeByte(buf, cursor)
+	if err != nil {
+		return 0, nil, err
+	}
+	cursor = c
+	k := *(*string)(unsafe.Pointer(&key))
+	field, exists := d.fieldMap[k]
+	if !exists {
+		return cursor, nil, nil
+	}
+	return cursor, field, nil
+}
+
+func decodeKeyByBitmapUint8Stream(d *structDecoder, s *Stream) (*structFieldSet, string, error) {
+	var (
+		curBit uint8 = math.MaxUint8
+	)
+	_, cursor, p := s.stat()
+	for {
+		switch char(p, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			return nil, "", errors.ErrInvalidBeginningOfValue(char(p, cursor), s.totalOffset())
+		case '"':
+			cursor++
+		FIRST_CHAR:
+			start := cursor
+			switch char(p, cursor) {
+			case '"':
+				cursor++
+				s.cursor = cursor
+				return nil, "", nil
+			case nul:
+				s.cursor = cursor
+				if s.read() {
+					_, cursor, p = s.stat()
+					goto FIRST_CHAR
+				}
+				return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+			}
+			keyIdx := 0
+			bitmap := d.keyBitmapUint8
+			for {
+				c := char(p, cursor)
+				switch c {
+				case '"':
+					fieldSetIndex := bits.TrailingZeros8(curBit)
+					field := d.sortedFieldSets[fieldSetIndex]
+					keyLen := cursor - start
+					cursor++
+					s.cursor = cursor
+					if keyLen < field.keyLen {
+						// early match
+						return nil, field.key, nil
+					}
+					return field, field.key, nil
+				case nul:
+					s.cursor = cursor
+					if s.read() {
+						_, cursor, p = s.stat()
+						continue
+					}
+					return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+				case '\\':
+					s.cursor = cursor + 1 // skip '\' char
+					chars, err := decodeKeyCharByEscapeCharStream(s)
+					if err != nil {
+						return nil, "", err
+					}
+					cursor = s.cursor
+					for _, c := range chars {
+						curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+						if curBit == 0 {
+							s.cursor = cursor
+							return decodeKeyNotFoundStream(s, start)
+						}
+						keyIdx++
+					}
+				default:
+					curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+					if curBit == 0 {
+						s.cursor = cursor
+						return decodeKeyNotFoundStream(s, start)
+					}
+					keyIdx++
+				}
+				cursor++
+			}
+		default:
+			return nil, "", errors.ErrInvalidBeginningOfValue(char(p, cursor), s.totalOffset())
+		}
+	}
+}
+
+func decodeKeyByBitmapUint16Stream(d *structDecoder, s *Stream) (*structFieldSet, string, error) {
+	var (
+		curBit uint16 = math.MaxUint16
+	)
+	_, cursor, p := s.stat()
+	for {
+		switch char(p, cursor) {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+		case nul:
+			s.cursor = cursor
+			if s.read() {
+				_, cursor, p = s.stat()
+				continue
+			}
+			return nil, "", errors.ErrInvalidBeginningOfValue(char(p, cursor), s.totalOffset())
+		case '"':
+			cursor++
+		FIRST_CHAR:
+			start := cursor
+			switch char(p, cursor) {
+			case '"':
+				cursor++
+				s.cursor = cursor
+				return nil, "", nil
+			case nul:
+				s.cursor = cursor
+				if s.read() {
+					_, cursor, p = s.stat()
+					goto FIRST_CHAR
+				}
+				return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+			}
+			keyIdx := 0
+			bitmap := d.keyBitmapUint16
+			for {
+				c := char(p, cursor)
+				switch c {
+				case '"':
+					fieldSetIndex := bits.TrailingZeros16(curBit)
+					field := d.sortedFieldSets[fieldSetIndex]
+					keyLen := cursor - start
+					cursor++
+					s.cursor = cursor
+					if keyLen < field.keyLen {
+						// early match
+						return nil, field.key, nil
+					}
+					return field, field.key, nil
+				case nul:
+					s.cursor = cursor
+					if s.read() {
+						_, cursor, p = s.stat()
+						continue
+					}
+					return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+				case '\\':
+					s.cursor = cursor + 1 // skip '\' char
+					chars, err := decodeKeyCharByEscapeCharStream(s)
+					if err != nil {
+						return nil, "", err
+					}
+					cursor = s.cursor
+					for _, c := range chars {
+						curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+						if curBit == 0 {
+							s.cursor = cursor
+							return decodeKeyNotFoundStream(s, start)
+						}
+						keyIdx++
+					}
+				default:
+					curBit &= bitmap[keyIdx][largeToSmallTable[c]]
+					if curBit == 0 {
+						s.cursor = cursor
+						return decodeKeyNotFoundStream(s, start)
+					}
+					keyIdx++
+				}
+				cursor++
+			}
+		default:
+			return nil, "", errors.ErrInvalidBeginningOfValue(char(p, cursor), s.totalOffset())
+		}
+	}
+}
+
+// decode from '\uXXXX'
+func decodeKeyCharByUnicodeRuneStream(s *Stream) ([]byte, error) {
+	const defaultOffset = 4
+	const surrogateOffset = 6
+
+	if s.cursor+defaultOffset >= s.length {
+		if !s.read() {
+			return nil, errors.ErrInvalidCharacter(s.char(), "escaped unicode char", s.totalOffset())
+		}
+	}
+
+	r := unicodeToRune(s.buf[s.cursor : s.cursor+defaultOffset])
+	if utf16.IsSurrogate(r) {
+		s.cursor += defaultOffset
+		if s.cursor+surrogateOffset >= s.length {
+			s.read()
+		}
+		if s.cursor+surrogateOffset >= s.length || s.buf[s.cursor] != '\\' || s.buf[s.cursor+1] != 'u' {
+			s.cursor += defaultOffset - 1
+			return []byte(string(unicode.ReplacementChar)), nil
+		}
+		r2 := unicodeToRune(s.buf[s.cursor+defaultOffset+2 : s.cursor+surrogateOffset])
+		if r := utf16.DecodeRune(r, r2); r != unicode.ReplacementChar {
+			s.cursor += defaultOffset - 1
+			return []byte(string(r)), nil
+		}
+	}
+	s.cursor += defaultOffset - 1
+	return []byte(string(r)), nil
+}
+
+func decodeKeyCharByEscapeCharStream(s *Stream) ([]byte, error) {
+	c := s.buf[s.cursor]
+	s.cursor++
+RETRY:
+	switch c {
+	case '"':
+		return []byte{'"'}, nil
+	case '\\':
+		return []byte{'\\'}, nil
+	case '/':
+		return []byte{'/'}, nil
+	case 'b':
+		return []byte{'\b'}, nil
+	case 'f':
+		return []byte{'\f'}, nil
+	case 'n':
+		return []byte{'\n'}, nil
+	case 'r':
+		return []byte{'\r'}, nil
+	case 't':
+		return []byte{'\t'}, nil
+	case 'u':
+		return decodeKeyCharByUnicodeRuneStream(s)
+	case nul:
+		if !s.read() {
+			return nil, errors.ErrInvalidCharacter(s.char(), "escaped char", s.totalOffset())
+		}
+		goto RETRY
+	default:
+		return nil, errors.ErrUnexpectedEndOfJSON("struct field", s.totalOffset())
+	}
+}
+
+func decodeKeyNotFoundStream(s *Stream, start int64) (*structFieldSet, string, error) {
+	buf, cursor, p := s.stat()
+	for {
+		cursor++
+		switch char(p, cursor) {
+		case '"':
+			b := buf[start:cursor]
+			key := *(*string)(unsafe.Pointer(&b))
+			cursor++
+			s.cursor = cursor
+			return nil, key, nil
+		case '\\':
+			cursor++
+			if char(p, cursor) == nul {
+				s.cursor = cursor
+				if !s.read() {
+					return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+				}
+				buf, cursor, p = s.statForRetry()
+			}
+		case nul:
+			s.cursor = cursor
+			if !s.read() {
+				return nil, "", errors.ErrUnexpectedEndOfJSON("string", s.totalOffset())
+			}
+			buf, cursor, p = s.statForRetry()
+		}
+	}
+}
+
+func decodeKeyStream(d *structDecoder, s *Stream) (*structFieldSet, string, error) {
+	key, err := d.stringDecoder.decodeStreamByte(s)
+	if err != nil {
+		return nil, "", err
+	}
+	k := *(*string)(unsafe.Pointer(&key))
+	return d.fieldMap[k], k, nil
+}
+
+func (d *structDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return errors.ErrExceededMaxDepth(s.char(), s.cursor)
+	}
+
+	c := s.skipWhiteSpace()
+	switch c {
+	case 'n':
+		if err := nullBytes(s); err != nil {
+			return err
+		}
+		return nil
+	default:
+		if s.char() != '{' {
+			return errors.ErrInvalidBeginningOfValue(s.char(), s.totalOffset())
+		}
+	}
+	s.cursor++
+	if s.skipWhiteSpace() == '}' {
+		s.cursor++
+		return nil
+	}
+	var (
+		seenFields   map[int]struct{}
+		seenFieldNum int
+	)
+	firstWin := (s.Option.Flags & FirstWinOption) != 0
+	if firstWin {
+		seenFields = make(map[int]struct{}, d.fieldUniqueNameNum)
+	}
+	for {
+		s.reset()
+		field, key, err := d.keyStreamDecoder(d, s)
+		if err != nil {
+			return err
+		}
+		if s.skipWhiteSpace() != ':' {
+			return errors.ErrExpected("colon after object key", s.totalOffset())
+		}
+		s.cursor++
+		if field != nil {
+			if field.err != nil {
+				return field.err
+			}
+			if firstWin {
+				if _, exists := seenFields[field.fieldIdx]; exists {
+					if err := s.skipValue(depth); err != nil {
+						return err
+					}
+				} else {
+					if err := field.dec.DecodeStream(s, depth, unsafe.Pointer(uintptr(p)+field.offset)); err != nil {
+						return err
+					}
+					seenFieldNum++
+					if d.fieldUniqueNameNum <= seenFieldNum {
+						return s.skipObject(depth)
+					}
+					seenFields[field.fieldIdx] = struct{}{}
+				}
+			} else {
+				if err := field.dec.DecodeStream(s, depth, unsafe.Pointer(uintptr(p)+field.offset)); err != nil {
+					return err
+				}
+			}
+		} else if s.DisallowUnknownFields {
+			return fmt.Errorf("json: unknown field %q", key)
+		} else {
+			if err := s.skipValue(depth); err != nil {
+				return err
+			}
+		}
+		c := s.skipWhiteSpace()
+		if c == '}' {
+			s.cursor++
+			return nil
+		}
+		if c != ',' {
+			return errors.ErrExpected("comma after object element", s.totalOffset())
+		}
+		s.cursor++
+	}
+}
+
+func (d *structDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	depth++
+	if depth > maxDecodeNestingDepth {
+		return 0, errors.ErrExceededMaxDepth(buf[cursor], cursor)
+	}
+	buflen := int64(len(buf))
+	cursor = skipWhiteSpace(buf, cursor)
+	b := (*sliceHeader)(unsafe.Pointer(&buf)).data
+	switch char(b, cursor) {
+	case 'n':
+		if err := validateNull(buf, cursor); err != nil {
+			return 0, err
+		}
+		cursor += 4
+		return cursor, nil
+	case '{':
+	default:
+		return 0, errors.ErrInvalidBeginningOfValue(char(b, cursor), cursor)
+	}
+	cursor++
+	cursor = skipWhiteSpace(buf, cursor)
+	if buf[cursor] == '}' {
+		cursor++
+		return cursor, nil
+	}
+	var (
+		seenFields   map[int]struct{}
+		seenFieldNum int
+	)
+	firstWin := (ctx.Option.Flags & FirstWinOption) != 0
+	if firstWin {
+		seenFields = make(map[int]struct{}, d.fieldUniqueNameNum)
+	}
+	for {
+		c, field, err := d.keyDecoder(d, buf, cursor)
+		if err != nil {
+			return 0, err
+		}
+		cursor = skipWhiteSpace(buf, c)
+		if char(b, cursor) != ':' {
+			return 0, errors.ErrExpected("colon after object key", cursor)
+		}
+		cursor++
+		if cursor >= buflen {
+			return 0, errors.ErrExpected("object value after colon", cursor)
+		}
+		if field != nil {
+			if field.err != nil {
+				return 0, field.err
+			}
+			if firstWin {
+				if _, exists := seenFields[field.fieldIdx]; exists {
+					c, err := skipValue(buf, cursor, depth)
+					if err != nil {
+						return 0, err
+					}
+					cursor = c
+				} else {
+					c, err := field.dec.Decode(ctx, cursor, depth, unsafe.Pointer(uintptr(p)+field.offset))
+					if err != nil {
+						return 0, err
+					}
+					cursor = c
+					seenFieldNum++
+					if d.fieldUniqueNameNum <= seenFieldNum {
+						return skipObject(buf, cursor, depth)
+					}
+					seenFields[field.fieldIdx] = struct{}{}
+				}
+			} else {
+				c, err := field.dec.Decode(ctx, cursor, depth, unsafe.Pointer(uintptr(p)+field.offset))
+				if err != nil {
+					return 0, err
+				}
+				cursor = c
+			}
+		} else {
+			c, err := skipValue(buf, cursor, depth)
+			if err != nil {
+				return 0, err
+			}
+			cursor = c
+		}
+		cursor = skipWhiteSpace(buf, cursor)
+		if char(b, cursor) == '}' {
+			cursor++
+			return cursor, nil
+		}
+		if char(b, cursor) != ',' {
+			return 0, errors.ErrExpected("comma after object element", cursor)
+		}
+		cursor++
+	}
+}
+
+func (d *structDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: struct decoder does not support decode path")
+}

internal/decoder/type.go

@@ -0,0 +1,30 @@
+package decoder
+
+import (
+	"context"
+	"encoding"
+	"encoding/json"
+	"reflect"
+	"unsafe"
+)
+
+type Decoder interface {
+	Decode(*RuntimeContext, int64, int64, unsafe.Pointer) (int64, error)
+	DecodePath(*RuntimeContext, int64, int64) ([][]byte, int64, error)
+	DecodeStream(*Stream, int64, unsafe.Pointer) error
+}
+
+const (
+	nul                   = '\000'
+	maxDecodeNestingDepth = 10000
+)
+
+type unmarshalerContext interface {
+	UnmarshalJSON(context.Context, []byte) error
+}
+
+var (
+	unmarshalJSONType        = reflect.TypeOf((*json.Unmarshaler)(nil)).Elem()
+	unmarshalJSONContextType = reflect.TypeOf((*unmarshalerContext)(nil)).Elem()
+	unmarshalTextType        = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
+)

internal/decoder/uint.go

@@ -0,0 +1,194 @@
+package decoder
+
+import (
+	"fmt"
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type uintDecoder struct {
+	typ        *runtime.Type
+	kind       reflect.Kind
+	op         func(unsafe.Pointer, uint64)
+	structName string
+	fieldName  string
+}
+
+func newUintDecoder(typ *runtime.Type, structName, fieldName string, op func(unsafe.Pointer, uint64)) *uintDecoder {
+	return &uintDecoder{
+		typ:        typ,
+		kind:       typ.Kind(),
+		op:         op,
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *uintDecoder) typeError(buf []byte, offset int64) *errors.UnmarshalTypeError {
+	return &errors.UnmarshalTypeError{
+		Value:  fmt.Sprintf("number %s", string(buf)),
+		Type:   runtime.RType2Type(d.typ),
+		Offset: offset,
+	}
+}
+
+var (
+	pow10u64 = [...]uint64{
+		1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09,
+		1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
+	}
+	pow10u64Len = len(pow10u64)
+)
+
+func (d *uintDecoder) parseUint(b []byte) (uint64, error) {
+	maxDigit := len(b)
+	if maxDigit > pow10u64Len {
+		return 0, fmt.Errorf("invalid length of number")
+	}
+	sum := uint64(0)
+	for i := 0; i < maxDigit; i++ {
+		c := uint64(b[i]) - 48
+		digitValue := pow10u64[maxDigit-i-1]
+		sum += c * digitValue
+	}
+	return sum, nil
+}
+
+func (d *uintDecoder) decodeStreamByte(s *Stream) ([]byte, error) {
+	for {
+		switch s.char() {
+		case ' ', '\n', '\t', '\r':
+			s.cursor++
+			continue
+		case '0':
+			s.cursor++
+			return numZeroBuf, nil
+		case '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := s.cursor
+			for {
+				s.cursor++
+				if numTable[s.char()] {
+					continue
+				} else if s.char() == nul {
+					if s.read() {
+						s.cursor-- // for retry current character
+						continue
+					}
+				}
+				break
+			}
+			num := s.buf[start:s.cursor]
+			return num, nil
+		case 'n':
+			if err := nullBytes(s); err != nil {
+				return nil, err
+			}
+			return nil, nil
+		case nul:
+			if s.read() {
+				continue
+			}
+		default:
+			return nil, d.typeError([]byte{s.char()}, s.totalOffset())
+		}
+		break
+	}
+	return nil, errors.ErrUnexpectedEndOfJSON("number(unsigned integer)", s.totalOffset())
+}
+
+func (d *uintDecoder) decodeByte(buf []byte, cursor int64) ([]byte, int64, error) {
+	for {
+		switch buf[cursor] {
+		case ' ', '\n', '\t', '\r':
+			cursor++
+			continue
+		case '0':
+			cursor++
+			return numZeroBuf, cursor, nil
+		case '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			start := cursor
+			cursor++
+			for numTable[buf[cursor]] {
+				cursor++
+			}
+			num := buf[start:cursor]
+			return num, cursor, nil
+		case 'n':
+			if err := validateNull(buf, cursor); err != nil {
+				return nil, 0, err
+			}
+			cursor += 4
+			return nil, cursor, nil
+		default:
+			return nil, 0, d.typeError([]byte{buf[cursor]}, cursor)
+		}
+	}
+}
+
+func (d *uintDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		return nil
+	}
+	u64, err := d.parseUint(bytes)
+	if err != nil {
+		return d.typeError(bytes, s.totalOffset())
+	}
+	switch d.kind {
+	case reflect.Uint8:
+		if (1 << 8) <= u64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	case reflect.Uint16:
+		if (1 << 16) <= u64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	case reflect.Uint32:
+		if (1 << 32) <= u64 {
+			return d.typeError(bytes, s.totalOffset())
+		}
+	}
+	d.op(p, u64)
+	return nil
+}
+
+func (d *uintDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		return c, nil
+	}
+	cursor = c
+	u64, err := d.parseUint(bytes)
+	if err != nil {
+		return 0, d.typeError(bytes, cursor)
+	}
+	switch d.kind {
+	case reflect.Uint8:
+		if (1 << 8) <= u64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	case reflect.Uint16:
+		if (1 << 16) <= u64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	case reflect.Uint32:
+		if (1 << 32) <= u64 {
+			return 0, d.typeError(bytes, cursor)
+		}
+	}
+	d.op(p, u64)
+	return cursor, nil
+}
+
+func (d *uintDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: uint decoder does not support decode path")
+}

internal/decoder/unmarshal_json.go

@@ -0,0 +1,104 @@
+package decoder
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type unmarshalJSONDecoder struct {
+	typ        *runtime.Type
+	structName string
+	fieldName  string
+}
+
+func newUnmarshalJSONDecoder(typ *runtime.Type, structName, fieldName string) *unmarshalJSONDecoder {
+	return &unmarshalJSONDecoder{
+		typ:        typ,
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *unmarshalJSONDecoder) annotateError(cursor int64, err error) {
+	switch e := err.(type) {
+	case *errors.UnmarshalTypeError:
+		e.Struct = d.structName
+		e.Field = d.fieldName
+	case *errors.SyntaxError:
+		e.Offset = cursor
+	}
+}
+
+func (d *unmarshalJSONDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	s.skipWhiteSpace()
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	v := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: p,
+	}))
+	switch v := v.(type) {
+	case unmarshalerContext:
+		var ctx context.Context
+		if (s.Option.Flags & ContextOption) != 0 {
+			ctx = s.Option.Context
+		} else {
+			ctx = context.Background()
+		}
+		if err := v.UnmarshalJSON(ctx, dst); err != nil {
+			d.annotateError(s.cursor, err)
+			return err
+		}
+	case json.Unmarshaler:
+		if err := v.UnmarshalJSON(dst); err != nil {
+			d.annotateError(s.cursor, err)
+			return err
+		}
+	}
+	return nil
+}
+
+func (d *unmarshalJSONDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	v := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: p,
+	}))
+	if (ctx.Option.Flags & ContextOption) != 0 {
+		if err := v.(unmarshalerContext).UnmarshalJSON(ctx.Option.Context, dst); err != nil {
+			d.annotateError(cursor, err)
+			return 0, err
+		}
+	} else {
+		if err := v.(json.Unmarshaler).UnmarshalJSON(dst); err != nil {
+			d.annotateError(cursor, err)
+			return 0, err
+		}
+	}
+	return end, nil
+}
+
+func (d *unmarshalJSONDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: unmarshal json decoder does not support decode path")
+}

internal/decoder/unmarshal_text.go

@@ -0,0 +1,285 @@
+package decoder
+
+import (
+	"bytes"
+	"encoding"
+	"fmt"
+	"unicode"
+	"unicode/utf16"
+	"unicode/utf8"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type unmarshalTextDecoder struct {
+	typ        *runtime.Type
+	structName string
+	fieldName  string
+}
+
+func newUnmarshalTextDecoder(typ *runtime.Type, structName, fieldName string) *unmarshalTextDecoder {
+	return &unmarshalTextDecoder{
+		typ:        typ,
+		structName: structName,
+		fieldName:  fieldName,
+	}
+}
+
+func (d *unmarshalTextDecoder) annotateError(cursor int64, err error) {
+	switch e := err.(type) {
+	case *errors.UnmarshalTypeError:
+		e.Struct = d.structName
+		e.Field = d.fieldName
+	case *errors.SyntaxError:
+		e.Offset = cursor
+	}
+}
+
+var (
+	nullbytes = []byte(`null`)
+)
+
+func (d *unmarshalTextDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	s.skipWhiteSpace()
+	start := s.cursor
+	if err := s.skipValue(depth); err != nil {
+		return err
+	}
+	src := s.buf[start:s.cursor]
+	if len(src) > 0 {
+		switch src[0] {
+		case '[':
+			return &errors.UnmarshalTypeError{
+				Value:  "array",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case '{':
+			return &errors.UnmarshalTypeError{
+				Value:  "object",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return &errors.UnmarshalTypeError{
+				Value:  "number",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: s.totalOffset(),
+			}
+		case 'n':
+			if bytes.Equal(src, nullbytes) {
+				*(*unsafe.Pointer)(p) = nil
+				return nil
+			}
+		}
+	}
+	dst := make([]byte, len(src))
+	copy(dst, src)
+
+	if b, ok := unquoteBytes(dst); ok {
+		dst = b
+	}
+	v := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: p,
+	}))
+	if err := v.(encoding.TextUnmarshaler).UnmarshalText(dst); err != nil {
+		d.annotateError(s.cursor, err)
+		return err
+	}
+	return nil
+}
+
+func (d *unmarshalTextDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	buf := ctx.Buf
+	cursor = skipWhiteSpace(buf, cursor)
+	start := cursor
+	end, err := skipValue(buf, cursor, depth)
+	if err != nil {
+		return 0, err
+	}
+	src := buf[start:end]
+	if len(src) > 0 {
+		switch src[0] {
+		case '[':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "array",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case '{':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "object",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return 0, &errors.UnmarshalTypeError{
+				Value:  "number",
+				Type:   runtime.RType2Type(d.typ),
+				Offset: start,
+			}
+		case 'n':
+			if bytes.Equal(src, nullbytes) {
+				*(*unsafe.Pointer)(p) = nil
+				return end, nil
+			}
+		}
+	}
+
+	if s, ok := unquoteBytes(src); ok {
+		src = s
+	}
+	v := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: d.typ,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+	if err := v.(encoding.TextUnmarshaler).UnmarshalText(src); err != nil {
+		d.annotateError(cursor, err)
+		return 0, err
+	}
+	return end, nil
+}
+
+func (d *unmarshalTextDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: unmarshal text decoder does not support decode path")
+}
+
+func unquoteBytes(s []byte) (t []byte, ok bool) { //nolint: nonamedreturns
+	length := len(s)
+	if length < 2 || s[0] != '"' || s[length-1] != '"' {
+		return
+	}
+	s = s[1 : length-1]
+	length -= 2
+
+	// Check for unusual characters. If there are none,
+	// then no unquoting is needed, so return a slice of the
+	// original bytes.
+	r := 0
+	for r < length {
+		c := s[r]
+		if c == '\\' || c == '"' || c < ' ' {
+			break
+		}
+		if c < utf8.RuneSelf {
+			r++
+			continue
+		}
+		rr, size := utf8.DecodeRune(s[r:])
+		if rr == utf8.RuneError && size == 1 {
+			break
+		}
+		r += size
+	}
+	if r == length {
+		return s, true
+	}
+
+	b := make([]byte, length+2*utf8.UTFMax)
+	w := copy(b, s[0:r])
+	for r < length {
+		// Out of room? Can only happen if s is full of
+		// malformed UTF-8 and we're replacing each
+		// byte with RuneError.
+		if w >= len(b)-2*utf8.UTFMax {
+			nb := make([]byte, (len(b)+utf8.UTFMax)*2)
+			copy(nb, b[0:w])
+			b = nb
+		}
+		switch c := s[r]; {
+		case c == '\\':
+			r++
+			if r >= length {
+				return
+			}
+			switch s[r] {
+			default:
+				return
+			case '"', '\\', '/', '\'':
+				b[w] = s[r]
+				r++
+				w++
+			case 'b':
+				b[w] = '\b'
+				r++
+				w++
+			case 'f':
+				b[w] = '\f'
+				r++
+				w++
+			case 'n':
+				b[w] = '\n'
+				r++
+				w++
+			case 'r':
+				b[w] = '\r'
+				r++
+				w++
+			case 't':
+				b[w] = '\t'
+				r++
+				w++
+			case 'u':
+				r--
+				rr := getu4(s[r:])
+				if rr < 0 {
+					return
+				}
+				r += 6
+				if utf16.IsSurrogate(rr) {
+					rr1 := getu4(s[r:])
+					if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
+						// A valid pair; consume.
+						r += 6
+						w += utf8.EncodeRune(b[w:], dec)
+						break
+					}
+					// Invalid surrogate; fall back to replacement rune.
+					rr = unicode.ReplacementChar
+				}
+				w += utf8.EncodeRune(b[w:], rr)
+			}
+
+		// Quote, control characters are invalid.
+		case c == '"', c < ' ':
+			return
+
+		// ASCII
+		case c < utf8.RuneSelf:
+			b[w] = c
+			r++
+			w++
+
+		// Coerce to well-formed UTF-8.
+		default:
+			rr, size := utf8.DecodeRune(s[r:])
+			r += size
+			w += utf8.EncodeRune(b[w:], rr)
+		}
+	}
+	return b[0:w], true
+}
+
+func getu4(s []byte) rune {
+	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
+		return -1
+	}
+	var r rune
+	for _, c := range s[2:6] {
+		switch {
+		case '0' <= c && c <= '9':
+			c = c - '0'
+		case 'a' <= c && c <= 'f':
+			c = c - 'a' + 10
+		case 'A' <= c && c <= 'F':
+			c = c - 'A' + 10
+		default:
+			return -1
+		}
+		r = r*16 + rune(c)
+	}
+	return r
+}

internal/decoder/wrapped_string.go

@@ -0,0 +1,73 @@
+package decoder
+
+import (
+	"fmt"
+	"reflect"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type wrappedStringDecoder struct {
+	typ           *runtime.Type
+	dec           Decoder
+	stringDecoder *stringDecoder
+	structName    string
+	fieldName     string
+	isPtrType     bool
+}
+
+func newWrappedStringDecoder(typ *runtime.Type, dec Decoder, structName, fieldName string) *wrappedStringDecoder {
+	return &wrappedStringDecoder{
+		typ:           typ,
+		dec:           dec,
+		stringDecoder: newStringDecoder(structName, fieldName),
+		structName:    structName,
+		fieldName:     fieldName,
+		isPtrType:     typ.Kind() == reflect.Ptr,
+	}
+}
+
+func (d *wrappedStringDecoder) DecodeStream(s *Stream, depth int64, p unsafe.Pointer) error {
+	bytes, err := d.stringDecoder.decodeStreamByte(s)
+	if err != nil {
+		return err
+	}
+	if bytes == nil {
+		if d.isPtrType {
+			*(*unsafe.Pointer)(p) = nil
+		}
+		return nil
+	}
+	b := make([]byte, len(bytes)+1)
+	copy(b, bytes)
+	if _, err := d.dec.Decode(&RuntimeContext{Buf: b}, 0, depth, p); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (d *wrappedStringDecoder) Decode(ctx *RuntimeContext, cursor, depth int64, p unsafe.Pointer) (int64, error) {
+	bytes, c, err := d.stringDecoder.decodeByte(ctx.Buf, cursor)
+	if err != nil {
+		return 0, err
+	}
+	if bytes == nil {
+		if d.isPtrType {
+			*(*unsafe.Pointer)(p) = nil
+		}
+		return c, nil
+	}
+	bytes = append(bytes, nul)
+	oldBuf := ctx.Buf
+	ctx.Buf = bytes
+	if _, err := d.dec.Decode(ctx, 0, depth, p); err != nil {
+		return 0, err
+	}
+	ctx.Buf = oldBuf
+	return c, nil
+}
+
+func (d *wrappedStringDecoder) DecodePath(ctx *RuntimeContext, cursor, depth int64) ([][]byte, int64, error) {
+	return nil, 0, fmt.Errorf("json: wrapped string decoder does not support decode path")
+}

internal/encoder/compact.go

@@ -0,0 +1,286 @@
+package encoder
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+var (
+	isWhiteSpace = [256]bool{
+		' ':  true,
+		'\n': true,
+		'\t': true,
+		'\r': true,
+	}
+	isHTMLEscapeChar = [256]bool{
+		'<': true,
+		'>': true,
+		'&': true,
+	}
+	nul = byte('\000')
+)
+
+func Compact(buf *bytes.Buffer, src []byte, escape bool) error {
+	if len(src) == 0 {
+		return errors.ErrUnexpectedEndOfJSON("", 0)
+	}
+	buf.Grow(len(src))
+	dst := buf.Bytes()
+
+	ctx := TakeRuntimeContext()
+	ctxBuf := ctx.Buf[:0]
+	ctxBuf = append(append(ctxBuf, src...), nul)
+	ctx.Buf = ctxBuf
+
+	if err := compactAndWrite(buf, dst, ctxBuf, escape); err != nil {
+		ReleaseRuntimeContext(ctx)
+		return err
+	}
+	ReleaseRuntimeContext(ctx)
+	return nil
+}
+
+func compactAndWrite(buf *bytes.Buffer, dst []byte, src []byte, escape bool) error {
+	dst, err := compact(dst, src, escape)
+	if err != nil {
+		return err
+	}
+	if _, err := buf.Write(dst); err != nil {
+		return err
+	}
+	return nil
+}
+
+func compact(dst, src []byte, escape bool) ([]byte, error) {
+	buf, cursor, err := compactValue(dst, src, 0, escape)
+	if err != nil {
+		return nil, err
+	}
+	if err := validateEndBuf(src, cursor); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func validateEndBuf(src []byte, cursor int64) error {
+	for {
+		switch src[cursor] {
+		case ' ', '\t', '\n', '\r':
+			cursor++
+			continue
+		case nul:
+			return nil
+		}
+		return errors.ErrSyntax(
+			fmt.Sprintf("invalid character '%c' after top-level value", src[cursor]),
+			cursor+1,
+		)
+	}
+}
+
+func skipWhiteSpace(buf []byte, cursor int64) int64 {
+LOOP:
+	if isWhiteSpace[buf[cursor]] {
+		cursor++
+		goto LOOP
+	}
+	return cursor
+}
+
+func compactValue(dst, src []byte, cursor int64, escape bool) ([]byte, int64, error) {
+	for {
+		switch src[cursor] {
+		case ' ', '\t', '\n', '\r':
+			cursor++
+			continue
+		case '{':
+			return compactObject(dst, src, cursor, escape)
+		case '}':
+			return nil, 0, errors.ErrSyntax("unexpected character '}'", cursor)
+		case '[':
+			return compactArray(dst, src, cursor, escape)
+		case ']':
+			return nil, 0, errors.ErrSyntax("unexpected character ']'", cursor)
+		case '"':
+			return compactString(dst, src, cursor, escape)
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return compactNumber(dst, src, cursor)
+		case 't':
+			return compactTrue(dst, src, cursor)
+		case 'f':
+			return compactFalse(dst, src, cursor)
+		case 'n':
+			return compactNull(dst, src, cursor)
+		default:
+			return nil, 0, errors.ErrSyntax(fmt.Sprintf("unexpected character '%c'", src[cursor]), cursor)
+		}
+	}
+}
+
+func compactObject(dst, src []byte, cursor int64, escape bool) ([]byte, int64, error) {
+	if src[cursor] == '{' {
+		dst = append(dst, '{')
+	} else {
+		return nil, 0, errors.ErrExpected("expected { character for object value", cursor)
+	}
+	cursor = skipWhiteSpace(src, cursor+1)
+	if src[cursor] == '}' {
+		dst = append(dst, '}')
+		return dst, cursor + 1, nil
+	}
+	var err error
+	for {
+		cursor = skipWhiteSpace(src, cursor)
+		dst, cursor, err = compactString(dst, src, cursor, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		if src[cursor] != ':' {
+			return nil, 0, errors.ErrExpected("colon after object key", cursor)
+		}
+		dst = append(dst, ':')
+		dst, cursor, err = compactValue(dst, src, cursor+1, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		switch src[cursor] {
+		case '}':
+			dst = append(dst, '}')
+			cursor++
+			return dst, cursor, nil
+		case ',':
+			dst = append(dst, ',')
+		default:
+			return nil, 0, errors.ErrExpected("comma after object value", cursor)
+		}
+		cursor++
+	}
+}
+
+func compactArray(dst, src []byte, cursor int64, escape bool) ([]byte, int64, error) {
+	if src[cursor] == '[' {
+		dst = append(dst, '[')
+	} else {
+		return nil, 0, errors.ErrExpected("expected [ character for array value", cursor)
+	}
+	cursor = skipWhiteSpace(src, cursor+1)
+	if src[cursor] == ']' {
+		dst = append(dst, ']')
+		return dst, cursor + 1, nil
+	}
+	var err error
+	for {
+		dst, cursor, err = compactValue(dst, src, cursor, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		switch src[cursor] {
+		case ']':
+			dst = append(dst, ']')
+			cursor++
+			return dst, cursor, nil
+		case ',':
+			dst = append(dst, ',')
+		default:
+			return nil, 0, errors.ErrExpected("comma after array value", cursor)
+		}
+		cursor++
+	}
+}
+
+func compactString(dst, src []byte, cursor int64, escape bool) ([]byte, int64, error) {
+	if src[cursor] != '"' {
+		return nil, 0, errors.ErrInvalidCharacter(src[cursor], "string", cursor)
+	}
+	start := cursor
+	for {
+		cursor++
+		c := src[cursor]
+		if escape {
+			if isHTMLEscapeChar[c] {
+				dst = append(dst, src[start:cursor]...)
+				dst = append(dst, `\u00`...)
+				dst = append(dst, hex[c>>4], hex[c&0xF])
+				start = cursor + 1
+			} else if c == 0xE2 && cursor+2 < int64(len(src)) && src[cursor+1] == 0x80 && src[cursor+2]&^1 == 0xA8 {
+				dst = append(dst, src[start:cursor]...)
+				dst = append(dst, `\u202`...)
+				dst = append(dst, hex[src[cursor+2]&0xF])
+				start = cursor + 3
+				cursor += 2
+			}
+		}
+		switch c {
+		case '\\':
+			cursor++
+			if src[cursor] == nul {
+				return nil, 0, errors.ErrUnexpectedEndOfJSON("string", int64(len(src)))
+			}
+		case '"':
+			cursor++
+			return append(dst, src[start:cursor]...), cursor, nil
+		case nul:
+			return nil, 0, errors.ErrUnexpectedEndOfJSON("string", int64(len(src)))
+		}
+	}
+}
+
+func compactNumber(dst, src []byte, cursor int64) ([]byte, int64, error) {
+	start := cursor
+	for {
+		cursor++
+		if floatTable[src[cursor]] {
+			continue
+		}
+		break
+	}
+	num := src[start:cursor]
+	if _, err := strconv.ParseFloat(*(*string)(unsafe.Pointer(&num)), 64); err != nil {
+		return nil, 0, err
+	}
+	dst = append(dst, num...)
+	return dst, cursor, nil
+}
+
+func compactTrue(dst, src []byte, cursor int64) ([]byte, int64, error) {
+	if cursor+3 >= int64(len(src)) {
+		return nil, 0, errors.ErrUnexpectedEndOfJSON("true", cursor)
+	}
+	if !bytes.Equal(src[cursor:cursor+4], []byte(`true`)) {
+		return nil, 0, errors.ErrInvalidCharacter(src[cursor], "true", cursor)
+	}
+	dst = append(dst, "true"...)
+	cursor += 4
+	return dst, cursor, nil
+}
+
+func compactFalse(dst, src []byte, cursor int64) ([]byte, int64, error) {
+	if cursor+4 >= int64(len(src)) {
+		return nil, 0, errors.ErrUnexpectedEndOfJSON("false", cursor)
+	}
+	if !bytes.Equal(src[cursor:cursor+5], []byte(`false`)) {
+		return nil, 0, errors.ErrInvalidCharacter(src[cursor], "false", cursor)
+	}
+	dst = append(dst, "false"...)
+	cursor += 5
+	return dst, cursor, nil
+}
+
+func compactNull(dst, src []byte, cursor int64) ([]byte, int64, error) {
+	if cursor+3 >= int64(len(src)) {
+		return nil, 0, errors.ErrUnexpectedEndOfJSON("null", cursor)
+	}
+	if !bytes.Equal(src[cursor:cursor+4], []byte(`null`)) {
+		return nil, 0, errors.ErrInvalidCharacter(src[cursor], "null", cursor)
+	}
+	dst = append(dst, "null"...)
+	cursor += 4
+	return dst, cursor, nil
+}

internal/encoder/compiler.go

@@ -0,0 +1,939 @@
+package encoder
+
+import (
+	"context"
+	"encoding"
+	"encoding/json"
+	"reflect"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type marshalerContext interface {
+	MarshalJSON(context.Context) ([]byte, error)
+}
+
+var (
+	marshalJSONType        = reflect.TypeOf((*json.Marshaler)(nil)).Elem()
+	marshalJSONContextType = reflect.TypeOf((*marshalerContext)(nil)).Elem()
+	marshalTextType        = reflect.TypeOf((*encoding.TextMarshaler)(nil)).Elem()
+	jsonNumberType         = reflect.TypeOf(json.Number(""))
+	cachedOpcodeSets       []*OpcodeSet
+	cachedOpcodeMap        unsafe.Pointer // map[uintptr]*OpcodeSet
+	typeAddr               *runtime.TypeAddr
+	initEncoderOnce        sync.Once
+)
+
+func initEncoder() {
+	initEncoderOnce.Do(func() {
+		typeAddr = runtime.AnalyzeTypeAddr()
+		if typeAddr == nil {
+			typeAddr = &runtime.TypeAddr{}
+		}
+		cachedOpcodeSets = make([]*OpcodeSet, typeAddr.AddrRange>>typeAddr.AddrShift+1)
+	})
+}
+
+func loadOpcodeMap() map[uintptr]*OpcodeSet {
+	p := atomic.LoadPointer(&cachedOpcodeMap)
+	return *(*map[uintptr]*OpcodeSet)(unsafe.Pointer(&p))
+}
+
+func storeOpcodeSet(typ uintptr, set *OpcodeSet, m map[uintptr]*OpcodeSet) {
+	newOpcodeMap := make(map[uintptr]*OpcodeSet, len(m)+1)
+	newOpcodeMap[typ] = set
+
+	for k, v := range m {
+		newOpcodeMap[k] = v
+	}
+
+	atomic.StorePointer(&cachedOpcodeMap, *(*unsafe.Pointer)(unsafe.Pointer(&newOpcodeMap)))
+}
+
+func compileToGetCodeSetSlowPath(typeptr uintptr) (*OpcodeSet, error) {
+	opcodeMap := loadOpcodeMap()
+	if codeSet, exists := opcodeMap[typeptr]; exists {
+		return codeSet, nil
+	}
+	codeSet, err := newCompiler().compile(typeptr)
+	if err != nil {
+		return nil, err
+	}
+	storeOpcodeSet(typeptr, codeSet, opcodeMap)
+	return codeSet, nil
+}
+
+func getFilteredCodeSetIfNeeded(ctx *RuntimeContext, codeSet *OpcodeSet) (*OpcodeSet, error) {
+	if (ctx.Option.Flag & ContextOption) == 0 {
+		return codeSet, nil
+	}
+	query := FieldQueryFromContext(ctx.Option.Context)
+	if query == nil {
+		return codeSet, nil
+	}
+	ctx.Option.Flag |= FieldQueryOption
+	cacheCodeSet := codeSet.getQueryCache(query.Hash())
+	if cacheCodeSet != nil {
+		return cacheCodeSet, nil
+	}
+	queryCodeSet, err := newCompiler().codeToOpcodeSet(codeSet.Type, codeSet.Code.Filter(query))
+	if err != nil {
+		return nil, err
+	}
+	codeSet.setQueryCache(query.Hash(), queryCodeSet)
+	return queryCodeSet, nil
+}
+
+type Compiler struct {
+	structTypeToCode map[uintptr]*StructCode
+}
+
+func newCompiler() *Compiler {
+	return &Compiler{
+		structTypeToCode: map[uintptr]*StructCode{},
+	}
+}
+
+func (c *Compiler) compile(typeptr uintptr) (*OpcodeSet, error) {
+	// noescape trick for header.typ ( reflect.*rtype )
+	typ := *(**runtime.Type)(unsafe.Pointer(&typeptr))
+	code, err := c.typeToCode(typ)
+	if err != nil {
+		return nil, err
+	}
+	return c.codeToOpcodeSet(typ, code)
+}
+
+func (c *Compiler) codeToOpcodeSet(typ *runtime.Type, code Code) (*OpcodeSet, error) {
+	noescapeKeyCode := c.codeToOpcode(&compileContext{
+		structTypeToCodes: map[uintptr]Opcodes{},
+		recursiveCodes:    &Opcodes{},
+	}, typ, code)
+	if err := noescapeKeyCode.Validate(); err != nil {
+		return nil, err
+	}
+	escapeKeyCode := c.codeToOpcode(&compileContext{
+		structTypeToCodes: map[uintptr]Opcodes{},
+		recursiveCodes:    &Opcodes{},
+		escapeKey:         true,
+	}, typ, code)
+	noescapeKeyCode = copyOpcode(noescapeKeyCode)
+	escapeKeyCode = copyOpcode(escapeKeyCode)
+	setTotalLengthToInterfaceOp(noescapeKeyCode)
+	setTotalLengthToInterfaceOp(escapeKeyCode)
+	interfaceNoescapeKeyCode := copyToInterfaceOpcode(noescapeKeyCode)
+	interfaceEscapeKeyCode := copyToInterfaceOpcode(escapeKeyCode)
+	codeLength := noescapeKeyCode.TotalLength()
+	return &OpcodeSet{
+		Type:                     typ,
+		NoescapeKeyCode:          noescapeKeyCode,
+		EscapeKeyCode:            escapeKeyCode,
+		InterfaceNoescapeKeyCode: interfaceNoescapeKeyCode,
+		InterfaceEscapeKeyCode:   interfaceEscapeKeyCode,
+		CodeLength:               codeLength,
+		EndCode:                  ToEndCode(interfaceNoescapeKeyCode),
+		Code:                     code,
+		QueryCache:               map[string]*OpcodeSet{},
+	}, nil
+}
+
+func (c *Compiler) typeToCode(typ *runtime.Type) (Code, error) {
+	switch {
+	case c.implementsMarshalJSON(typ):
+		return c.marshalJSONCode(typ)
+	case c.implementsMarshalText(typ):
+		return c.marshalTextCode(typ)
+	}
+
+	isPtr := false
+	orgType := typ
+	if typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+		isPtr = true
+	}
+	switch {
+	case c.implementsMarshalJSON(typ):
+		return c.marshalJSONCode(orgType)
+	case c.implementsMarshalText(typ):
+		return c.marshalTextCode(orgType)
+	}
+	switch typ.Kind() {
+	case reflect.Slice:
+		elem := typ.Elem()
+		if elem.Kind() == reflect.Uint8 {
+			p := runtime.PtrTo(elem)
+			if !c.implementsMarshalJSONType(p) && !p.Implements(marshalTextType) {
+				return c.bytesCode(typ, isPtr)
+			}
+		}
+		return c.sliceCode(typ)
+	case reflect.Map:
+		if isPtr {
+			return c.ptrCode(runtime.PtrTo(typ))
+		}
+		return c.mapCode(typ)
+	case reflect.Struct:
+		return c.structCode(typ, isPtr)
+	case reflect.Int:
+		return c.intCode(typ, isPtr)
+	case reflect.Int8:
+		return c.int8Code(typ, isPtr)
+	case reflect.Int16:
+		return c.int16Code(typ, isPtr)
+	case reflect.Int32:
+		return c.int32Code(typ, isPtr)
+	case reflect.Int64:
+		return c.int64Code(typ, isPtr)
+	case reflect.Uint, reflect.Uintptr:
+		return c.uintCode(typ, isPtr)
+	case reflect.Uint8:
+		return c.uint8Code(typ, isPtr)
+	case reflect.Uint16:
+		return c.uint16Code(typ, isPtr)
+	case reflect.Uint32:
+		return c.uint32Code(typ, isPtr)
+	case reflect.Uint64:
+		return c.uint64Code(typ, isPtr)
+	case reflect.Float32:
+		return c.float32Code(typ, isPtr)
+	case reflect.Float64:
+		return c.float64Code(typ, isPtr)
+	case reflect.String:
+		return c.stringCode(typ, isPtr)
+	case reflect.Bool:
+		return c.boolCode(typ, isPtr)
+	case reflect.Interface:
+		return c.interfaceCode(typ, isPtr)
+	default:
+		if isPtr && typ.Implements(marshalTextType) {
+			typ = orgType
+		}
+		return c.typeToCodeWithPtr(typ, isPtr)
+	}
+}
+
+func (c *Compiler) typeToCodeWithPtr(typ *runtime.Type, isPtr bool) (Code, error) {
+	switch {
+	case c.implementsMarshalJSON(typ):
+		return c.marshalJSONCode(typ)
+	case c.implementsMarshalText(typ):
+		return c.marshalTextCode(typ)
+	}
+	switch typ.Kind() {
+	case reflect.Ptr:
+		return c.ptrCode(typ)
+	case reflect.Slice:
+		elem := typ.Elem()
+		if elem.Kind() == reflect.Uint8 {
+			p := runtime.PtrTo(elem)
+			if !c.implementsMarshalJSONType(p) && !p.Implements(marshalTextType) {
+				return c.bytesCode(typ, false)
+			}
+		}
+		return c.sliceCode(typ)
+	case reflect.Array:
+		return c.arrayCode(typ)
+	case reflect.Map:
+		return c.mapCode(typ)
+	case reflect.Struct:
+		return c.structCode(typ, isPtr)
+	case reflect.Interface:
+		return c.interfaceCode(typ, false)
+	case reflect.Int:
+		return c.intCode(typ, false)
+	case reflect.Int8:
+		return c.int8Code(typ, false)
+	case reflect.Int16:
+		return c.int16Code(typ, false)
+	case reflect.Int32:
+		return c.int32Code(typ, false)
+	case reflect.Int64:
+		return c.int64Code(typ, false)
+	case reflect.Uint:
+		return c.uintCode(typ, false)
+	case reflect.Uint8:
+		return c.uint8Code(typ, false)
+	case reflect.Uint16:
+		return c.uint16Code(typ, false)
+	case reflect.Uint32:
+		return c.uint32Code(typ, false)
+	case reflect.Uint64:
+		return c.uint64Code(typ, false)
+	case reflect.Uintptr:
+		return c.uintCode(typ, false)
+	case reflect.Float32:
+		return c.float32Code(typ, false)
+	case reflect.Float64:
+		return c.float64Code(typ, false)
+	case reflect.String:
+		return c.stringCode(typ, false)
+	case reflect.Bool:
+		return c.boolCode(typ, false)
+	}
+	return nil, &errors.UnsupportedTypeError{Type: runtime.RType2Type(typ)}
+}
+
+const intSize = 32 << (^uint(0) >> 63)
+
+//nolint:unparam
+func (c *Compiler) intCode(typ *runtime.Type, isPtr bool) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: intSize, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int8Code(typ *runtime.Type, isPtr bool) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 8, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int16Code(typ *runtime.Type, isPtr bool) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 16, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int32Code(typ *runtime.Type, isPtr bool) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 32, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int64Code(typ *runtime.Type, isPtr bool) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 64, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uintCode(typ *runtime.Type, isPtr bool) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: intSize, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint8Code(typ *runtime.Type, isPtr bool) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 8, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint16Code(typ *runtime.Type, isPtr bool) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 16, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint32Code(typ *runtime.Type, isPtr bool) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 32, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint64Code(typ *runtime.Type, isPtr bool) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 64, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) float32Code(typ *runtime.Type, isPtr bool) (*FloatCode, error) {
+	return &FloatCode{typ: typ, bitSize: 32, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) float64Code(typ *runtime.Type, isPtr bool) (*FloatCode, error) {
+	return &FloatCode{typ: typ, bitSize: 64, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) stringCode(typ *runtime.Type, isPtr bool) (*StringCode, error) {
+	return &StringCode{typ: typ, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) boolCode(typ *runtime.Type, isPtr bool) (*BoolCode, error) {
+	return &BoolCode{typ: typ, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) intStringCode(typ *runtime.Type) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: intSize, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int8StringCode(typ *runtime.Type) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 8, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int16StringCode(typ *runtime.Type) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 16, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int32StringCode(typ *runtime.Type) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 32, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) int64StringCode(typ *runtime.Type) (*IntCode, error) {
+	return &IntCode{typ: typ, bitSize: 64, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uintStringCode(typ *runtime.Type) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: intSize, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint8StringCode(typ *runtime.Type) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 8, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint16StringCode(typ *runtime.Type) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 16, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint32StringCode(typ *runtime.Type) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 32, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) uint64StringCode(typ *runtime.Type) (*UintCode, error) {
+	return &UintCode{typ: typ, bitSize: 64, isString: true}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) bytesCode(typ *runtime.Type, isPtr bool) (*BytesCode, error) {
+	return &BytesCode{typ: typ, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) interfaceCode(typ *runtime.Type, isPtr bool) (*InterfaceCode, error) {
+	return &InterfaceCode{typ: typ, isPtr: isPtr}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) marshalJSONCode(typ *runtime.Type) (*MarshalJSONCode, error) {
+	return &MarshalJSONCode{
+		typ:                typ,
+		isAddrForMarshaler: c.isPtrMarshalJSONType(typ),
+		isNilableType:      c.isNilableType(typ),
+		isMarshalerContext: typ.Implements(marshalJSONContextType) || runtime.PtrTo(typ).Implements(marshalJSONContextType),
+	}, nil
+}
+
+//nolint:unparam
+func (c *Compiler) marshalTextCode(typ *runtime.Type) (*MarshalTextCode, error) {
+	return &MarshalTextCode{
+		typ:                typ,
+		isAddrForMarshaler: c.isPtrMarshalTextType(typ),
+		isNilableType:      c.isNilableType(typ),
+	}, nil
+}
+
+func (c *Compiler) ptrCode(typ *runtime.Type) (*PtrCode, error) {
+	code, err := c.typeToCodeWithPtr(typ.Elem(), true)
+	if err != nil {
+		return nil, err
+	}
+	ptr, ok := code.(*PtrCode)
+	if ok {
+		return &PtrCode{typ: typ, value: ptr.value, ptrNum: ptr.ptrNum + 1}, nil
+	}
+	return &PtrCode{typ: typ, value: code, ptrNum: 1}, nil
+}
+
+func (c *Compiler) sliceCode(typ *runtime.Type) (*SliceCode, error) {
+	elem := typ.Elem()
+	code, err := c.listElemCode(elem)
+	if err != nil {
+		return nil, err
+	}
+	if code.Kind() == CodeKindStruct {
+		structCode := code.(*StructCode)
+		structCode.enableIndirect()
+	}
+	return &SliceCode{typ: typ, value: code}, nil
+}
+
+func (c *Compiler) arrayCode(typ *runtime.Type) (*ArrayCode, error) {
+	elem := typ.Elem()
+	code, err := c.listElemCode(elem)
+	if err != nil {
+		return nil, err
+	}
+	if code.Kind() == CodeKindStruct {
+		structCode := code.(*StructCode)
+		structCode.enableIndirect()
+	}
+	return &ArrayCode{typ: typ, value: code}, nil
+}
+
+func (c *Compiler) mapCode(typ *runtime.Type) (*MapCode, error) {
+	keyCode, err := c.mapKeyCode(typ.Key())
+	if err != nil {
+		return nil, err
+	}
+	valueCode, err := c.mapValueCode(typ.Elem())
+	if err != nil {
+		return nil, err
+	}
+	if valueCode.Kind() == CodeKindStruct {
+		structCode := valueCode.(*StructCode)
+		structCode.enableIndirect()
+	}
+	return &MapCode{typ: typ, key: keyCode, value: valueCode}, nil
+}
+
+func (c *Compiler) listElemCode(typ *runtime.Type) (Code, error) {
+	switch {
+	case c.implementsMarshalJSONType(typ) || c.implementsMarshalJSONType(runtime.PtrTo(typ)):
+		return c.marshalJSONCode(typ)
+	case !typ.Implements(marshalTextType) && runtime.PtrTo(typ).Implements(marshalTextType):
+		return c.marshalTextCode(typ)
+	case typ.Kind() == reflect.Map:
+		return c.ptrCode(runtime.PtrTo(typ))
+	default:
+		// isPtr was originally used to indicate whether the type of top level is pointer.
+		// However, since the slice/array element is a specification that can get the pointer address, explicitly set isPtr to true.
+		// See here for related issues: https://github.com/goccy/go-json/issues/370
+		code, err := c.typeToCodeWithPtr(typ, true)
+		if err != nil {
+			return nil, err
+		}
+		ptr, ok := code.(*PtrCode)
+		if ok {
+			if ptr.value.Kind() == CodeKindMap {
+				ptr.ptrNum++
+			}
+		}
+		return code, nil
+	}
+}
+
+func (c *Compiler) mapKeyCode(typ *runtime.Type) (Code, error) {
+	switch {
+	case c.implementsMarshalText(typ):
+		return c.marshalTextCode(typ)
+	}
+	switch typ.Kind() {
+	case reflect.Ptr:
+		return c.ptrCode(typ)
+	case reflect.String:
+		return c.stringCode(typ, false)
+	case reflect.Int:
+		return c.intStringCode(typ)
+	case reflect.Int8:
+		return c.int8StringCode(typ)
+	case reflect.Int16:
+		return c.int16StringCode(typ)
+	case reflect.Int32:
+		return c.int32StringCode(typ)
+	case reflect.Int64:
+		return c.int64StringCode(typ)
+	case reflect.Uint:
+		return c.uintStringCode(typ)
+	case reflect.Uint8:
+		return c.uint8StringCode(typ)
+	case reflect.Uint16:
+		return c.uint16StringCode(typ)
+	case reflect.Uint32:
+		return c.uint32StringCode(typ)
+	case reflect.Uint64:
+		return c.uint64StringCode(typ)
+	case reflect.Uintptr:
+		return c.uintStringCode(typ)
+	}
+	return nil, &errors.UnsupportedTypeError{Type: runtime.RType2Type(typ)}
+}
+
+func (c *Compiler) mapValueCode(typ *runtime.Type) (Code, error) {
+	switch typ.Kind() {
+	case reflect.Map:
+		return c.ptrCode(runtime.PtrTo(typ))
+	default:
+		code, err := c.typeToCodeWithPtr(typ, false)
+		if err != nil {
+			return nil, err
+		}
+		ptr, ok := code.(*PtrCode)
+		if ok {
+			if ptr.value.Kind() == CodeKindMap {
+				ptr.ptrNum++
+			}
+		}
+		return code, nil
+	}
+}
+
+func (c *Compiler) structCode(typ *runtime.Type, isPtr bool) (*StructCode, error) {
+	typeptr := uintptr(unsafe.Pointer(typ))
+	if code, exists := c.structTypeToCode[typeptr]; exists {
+		derefCode := *code
+		derefCode.isRecursive = true
+		return &derefCode, nil
+	}
+	indirect := runtime.IfaceIndir(typ)
+	code := &StructCode{typ: typ, isPtr: isPtr, isIndirect: indirect}
+	c.structTypeToCode[typeptr] = code
+
+	fieldNum := typ.NumField()
+	tags := c.typeToStructTags(typ)
+	fields := []*StructFieldCode{}
+	for i, tag := range tags {
+		isOnlyOneFirstField := i == 0 && fieldNum == 1
+		field, err := c.structFieldCode(code, tag, isPtr, isOnlyOneFirstField)
+		if err != nil {
+			return nil, err
+		}
+		if field.isAnonymous {
+			structCode := field.getAnonymousStruct()
+			if structCode != nil {
+				structCode.removeFieldsByTags(tags)
+				if c.isAssignableIndirect(field, isPtr) {
+					if indirect {
+						structCode.isIndirect = true
+					} else {
+						structCode.isIndirect = false
+					}
+				}
+			}
+		} else {
+			structCode := field.getStruct()
+			if structCode != nil {
+				if indirect {
+					// if parent is indirect type, set child indirect property to true
+					structCode.isIndirect = true
+				} else {
+					// if parent is not indirect type, set child indirect property to false.
+					// but if parent's indirect is false and isPtr is true, then indirect must be true.
+					// Do this only if indirectConversion is enabled at the end of compileStruct.
+					structCode.isIndirect = false
+				}
+			}
+		}
+		fields = append(fields, field)
+	}
+	fieldMap := c.getFieldMap(fields)
+	duplicatedFieldMap := c.getDuplicatedFieldMap(fieldMap)
+	code.fields = c.filteredDuplicatedFields(fields, duplicatedFieldMap)
+	if !code.disableIndirectConversion && !indirect && isPtr {
+		code.enableIndirect()
+	}
+	delete(c.structTypeToCode, typeptr)
+	return code, nil
+}
+
+func toElemType(t *runtime.Type) *runtime.Type {
+	for t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+	return t
+}
+
+func (c *Compiler) structFieldCode(structCode *StructCode, tag *runtime.StructTag, isPtr, isOnlyOneFirstField bool) (*StructFieldCode, error) {
+	field := tag.Field
+	fieldType := runtime.Type2RType(field.Type)
+	isIndirectSpecialCase := isPtr && isOnlyOneFirstField
+	fieldCode := &StructFieldCode{
+		typ:           fieldType,
+		key:           tag.Key,
+		tag:           tag,
+		offset:        field.Offset,
+		isAnonymous:   field.Anonymous && !tag.IsTaggedKey && toElemType(fieldType).Kind() == reflect.Struct,
+		isTaggedKey:   tag.IsTaggedKey,
+		isNilableType: c.isNilableType(fieldType),
+		isNilCheck:    true,
+	}
+	switch {
+	case c.isMovePointerPositionFromHeadToFirstMarshalJSONFieldCase(fieldType, isIndirectSpecialCase):
+		code, err := c.marshalJSONCode(fieldType)
+		if err != nil {
+			return nil, err
+		}
+		fieldCode.value = code
+		fieldCode.isAddrForMarshaler = true
+		fieldCode.isNilCheck = false
+		structCode.isIndirect = false
+		structCode.disableIndirectConversion = true
+	case c.isMovePointerPositionFromHeadToFirstMarshalTextFieldCase(fieldType, isIndirectSpecialCase):
+		code, err := c.marshalTextCode(fieldType)
+		if err != nil {
+			return nil, err
+		}
+		fieldCode.value = code
+		fieldCode.isAddrForMarshaler = true
+		fieldCode.isNilCheck = false
+		structCode.isIndirect = false
+		structCode.disableIndirectConversion = true
+	case isPtr && c.isPtrMarshalJSONType(fieldType):
+		// *struct{ field T }
+		// func (*T) MarshalJSON() ([]byte, error)
+		code, err := c.marshalJSONCode(fieldType)
+		if err != nil {
+			return nil, err
+		}
+		fieldCode.value = code
+		fieldCode.isAddrForMarshaler = true
+		fieldCode.isNilCheck = false
+	case isPtr && c.isPtrMarshalTextType(fieldType):
+		// *struct{ field T }
+		// func (*T) MarshalText() ([]byte, error)
+		code, err := c.marshalTextCode(fieldType)
+		if err != nil {
+			return nil, err
+		}
+		fieldCode.value = code
+		fieldCode.isAddrForMarshaler = true
+		fieldCode.isNilCheck = false
+	default:
+		code, err := c.typeToCodeWithPtr(fieldType, isPtr)
+		if err != nil {
+			return nil, err
+		}
+		switch code.Kind() {
+		case CodeKindPtr, CodeKindInterface:
+			fieldCode.isNextOpPtrType = true
+		}
+		fieldCode.value = code
+	}
+	return fieldCode, nil
+}
+
+func (c *Compiler) isAssignableIndirect(fieldCode *StructFieldCode, isPtr bool) bool {
+	if isPtr {
+		return false
+	}
+	codeType := fieldCode.value.Kind()
+	if codeType == CodeKindMarshalJSON {
+		return false
+	}
+	if codeType == CodeKindMarshalText {
+		return false
+	}
+	return true
+}
+
+func (c *Compiler) getFieldMap(fields []*StructFieldCode) map[string][]*StructFieldCode {
+	fieldMap := map[string][]*StructFieldCode{}
+	for _, field := range fields {
+		if field.isAnonymous {
+			for k, v := range c.getAnonymousFieldMap(field) {
+				fieldMap[k] = append(fieldMap[k], v...)
+			}
+			continue
+		}
+		fieldMap[field.key] = append(fieldMap[field.key], field)
+	}
+	return fieldMap
+}
+
+func (c *Compiler) getAnonymousFieldMap(field *StructFieldCode) map[string][]*StructFieldCode {
+	fieldMap := map[string][]*StructFieldCode{}
+	structCode := field.getAnonymousStruct()
+	if structCode == nil || structCode.isRecursive {
+		fieldMap[field.key] = append(fieldMap[field.key], field)
+		return fieldMap
+	}
+	for k, v := range c.getFieldMapFromAnonymousParent(structCode.fields) {
+		fieldMap[k] = append(fieldMap[k], v...)
+	}
+	return fieldMap
+}
+
+func (c *Compiler) getFieldMapFromAnonymousParent(fields []*StructFieldCode) map[string][]*StructFieldCode {
+	fieldMap := map[string][]*StructFieldCode{}
+	for _, field := range fields {
+		if field.isAnonymous {
+			for k, v := range c.getAnonymousFieldMap(field) {
+				// Do not handle tagged key when embedding more than once
+				for _, vv := range v {
+					vv.isTaggedKey = false
+				}
+				fieldMap[k] = append(fieldMap[k], v...)
+			}
+			continue
+		}
+		fieldMap[field.key] = append(fieldMap[field.key], field)
+	}
+	return fieldMap
+}
+
+func (c *Compiler) getDuplicatedFieldMap(fieldMap map[string][]*StructFieldCode) map[*StructFieldCode]struct{} {
+	duplicatedFieldMap := map[*StructFieldCode]struct{}{}
+	for _, fields := range fieldMap {
+		if len(fields) == 1 {
+			continue
+		}
+		if c.isTaggedKeyOnly(fields) {
+			for _, field := range fields {
+				if field.isTaggedKey {
+					continue
+				}
+				duplicatedFieldMap[field] = struct{}{}
+			}
+		} else {
+			for _, field := range fields {
+				duplicatedFieldMap[field] = struct{}{}
+			}
+		}
+	}
+	return duplicatedFieldMap
+}
+
+func (c *Compiler) filteredDuplicatedFields(fields []*StructFieldCode, duplicatedFieldMap map[*StructFieldCode]struct{}) []*StructFieldCode {
+	filteredFields := make([]*StructFieldCode, 0, len(fields))
+	for _, field := range fields {
+		if field.isAnonymous {
+			structCode := field.getAnonymousStruct()
+			if structCode != nil && !structCode.isRecursive {
+				structCode.fields = c.filteredDuplicatedFields(structCode.fields, duplicatedFieldMap)
+				if len(structCode.fields) > 0 {
+					filteredFields = append(filteredFields, field)
+				}
+				continue
+			}
+		}
+		if _, exists := duplicatedFieldMap[field]; exists {
+			continue
+		}
+		filteredFields = append(filteredFields, field)
+	}
+	return filteredFields
+}
+
+func (c *Compiler) isTaggedKeyOnly(fields []*StructFieldCode) bool {
+	var taggedKeyFieldCount int
+	for _, field := range fields {
+		if field.isTaggedKey {
+			taggedKeyFieldCount++
+		}
+	}
+	return taggedKeyFieldCount == 1
+}
+
+func (c *Compiler) typeToStructTags(typ *runtime.Type) runtime.StructTags {
+	tags := runtime.StructTags{}
+	fieldNum := typ.NumField()
+	for i := 0; i < fieldNum; i++ {
+		field := typ.Field(i)
+		if runtime.IsIgnoredStructField(field) {
+			continue
+		}
+		tags = append(tags, runtime.StructTagFromField(field))
+	}
+	return tags
+}
+
+// *struct{ field T } => struct { field *T }
+// func (*T) MarshalJSON() ([]byte, error)
+func (c *Compiler) isMovePointerPositionFromHeadToFirstMarshalJSONFieldCase(typ *runtime.Type, isIndirectSpecialCase bool) bool {
+	return isIndirectSpecialCase && !c.isNilableType(typ) && c.isPtrMarshalJSONType(typ)
+}
+
+// *struct{ field T } => struct { field *T }
+// func (*T) MarshalText() ([]byte, error)
+func (c *Compiler) isMovePointerPositionFromHeadToFirstMarshalTextFieldCase(typ *runtime.Type, isIndirectSpecialCase bool) bool {
+	return isIndirectSpecialCase && !c.isNilableType(typ) && c.isPtrMarshalTextType(typ)
+}
+
+func (c *Compiler) implementsMarshalJSON(typ *runtime.Type) bool {
+	if !c.implementsMarshalJSONType(typ) {
+		return false
+	}
+	if typ.Kind() != reflect.Ptr {
+		return true
+	}
+	// type kind is reflect.Ptr
+	if !c.implementsMarshalJSONType(typ.Elem()) {
+		return true
+	}
+	// needs to dereference
+	return false
+}
+
+func (c *Compiler) implementsMarshalText(typ *runtime.Type) bool {
+	if !typ.Implements(marshalTextType) {
+		return false
+	}
+	if typ.Kind() != reflect.Ptr {
+		return true
+	}
+	// type kind is reflect.Ptr
+	if !typ.Elem().Implements(marshalTextType) {
+		return true
+	}
+	// needs to dereference
+	return false
+}
+
+func (c *Compiler) isNilableType(typ *runtime.Type) bool {
+	if !runtime.IfaceIndir(typ) {
+		return true
+	}
+	switch typ.Kind() {
+	case reflect.Ptr:
+		return true
+	case reflect.Map:
+		return true
+	case reflect.Func:
+		return true
+	default:
+		return false
+	}
+}
+
+func (c *Compiler) implementsMarshalJSONType(typ *runtime.Type) bool {
+	return typ.Implements(marshalJSONType) || typ.Implements(marshalJSONContextType)
+}
+
+func (c *Compiler) isPtrMarshalJSONType(typ *runtime.Type) bool {
+	return !c.implementsMarshalJSONType(typ) && c.implementsMarshalJSONType(runtime.PtrTo(typ))
+}
+
+func (c *Compiler) isPtrMarshalTextType(typ *runtime.Type) bool {
+	return !typ.Implements(marshalTextType) && runtime.PtrTo(typ).Implements(marshalTextType)
+}
+
+func (c *Compiler) codeToOpcode(ctx *compileContext, typ *runtime.Type, code Code) *Opcode {
+	codes := code.ToOpcode(ctx)
+	codes.Last().Next = newEndOp(ctx, typ)
+	c.linkRecursiveCode(ctx)
+	return codes.First()
+}
+
+func (c *Compiler) linkRecursiveCode(ctx *compileContext) {
+	recursiveCodes := map[uintptr]*CompiledCode{}
+	for _, recursive := range *ctx.recursiveCodes {
+		typeptr := uintptr(unsafe.Pointer(recursive.Type))
+		codes := ctx.structTypeToCodes[typeptr]
+		if recursiveCode, ok := recursiveCodes[typeptr]; ok {
+			*recursive.Jmp = *recursiveCode
+			continue
+		}
+
+		code := copyOpcode(codes.First())
+		code.Op = code.Op.PtrHeadToHead()
+		lastCode := newEndOp(&compileContext{}, recursive.Type)
+		lastCode.Op = OpRecursiveEnd
+
+		// OpRecursiveEnd must set before call TotalLength
+		code.End.Next = lastCode
+
+		totalLength := code.TotalLength()
+
+		// Idx, ElemIdx, Length must set after call TotalLength
+		lastCode.Idx = uint32((totalLength + 1) * uintptrSize)
+		lastCode.ElemIdx = lastCode.Idx + uintptrSize
+		lastCode.Length = lastCode.Idx + 2*uintptrSize
+
+		// extend length to alloc slot for elemIdx + length
+		curTotalLength := uintptr(recursive.TotalLength()) + 3
+		nextTotalLength := uintptr(totalLength) + 3
+
+		compiled := recursive.Jmp
+		compiled.Code = code
+		compiled.CurLen = curTotalLength
+		compiled.NextLen = nextTotalLength
+		compiled.Linked = true
+
+		recursiveCodes[typeptr] = compiled
+	}
+}

internal/encoder/compiler_norace.go

@@ -0,0 +1,33 @@
+//go:build !race
+// +build !race
+
+package encoder
+
+func CompileToGetCodeSet(ctx *RuntimeContext, typeptr uintptr) (*OpcodeSet, error) {
+	initEncoder()
+	if typeptr > typeAddr.MaxTypeAddr || typeptr < typeAddr.BaseTypeAddr {
+		codeSet, err := compileToGetCodeSetSlowPath(typeptr)
+		if err != nil {
+			return nil, err
+		}
+		return getFilteredCodeSetIfNeeded(ctx, codeSet)
+	}
+	index := (typeptr - typeAddr.BaseTypeAddr) >> typeAddr.AddrShift
+	if codeSet := cachedOpcodeSets[index]; codeSet != nil {
+		filtered, err := getFilteredCodeSetIfNeeded(ctx, codeSet)
+		if err != nil {
+			return nil, err
+		}
+		return filtered, nil
+	}
+	codeSet, err := newCompiler().compile(typeptr)
+	if err != nil {
+		return nil, err
+	}
+	filtered, err := getFilteredCodeSetIfNeeded(ctx, codeSet)
+	if err != nil {
+		return nil, err
+	}
+	cachedOpcodeSets[index] = codeSet
+	return filtered, nil
+}

internal/encoder/compiler_race.go

@@ -0,0 +1,46 @@
+//go:build race
+// +build race
+
+package encoder
+
+import (
+	"sync"
+)
+
+var setsMu sync.RWMutex
+
+func CompileToGetCodeSet(ctx *RuntimeContext, typeptr uintptr) (*OpcodeSet, error) {
+	initEncoder()
+	if typeptr > typeAddr.MaxTypeAddr || typeptr < typeAddr.BaseTypeAddr {
+		codeSet, err := compileToGetCodeSetSlowPath(typeptr)
+		if err != nil {
+			return nil, err
+		}
+		return getFilteredCodeSetIfNeeded(ctx, codeSet)
+	}
+	index := (typeptr - typeAddr.BaseTypeAddr) >> typeAddr.AddrShift
+	setsMu.RLock()
+	if codeSet := cachedOpcodeSets[index]; codeSet != nil {
+		filtered, err := getFilteredCodeSetIfNeeded(ctx, codeSet)
+		if err != nil {
+			setsMu.RUnlock()
+			return nil, err
+		}
+		setsMu.RUnlock()
+		return filtered, nil
+	}
+	setsMu.RUnlock()
+
+	codeSet, err := newCompiler().compile(typeptr)
+	if err != nil {
+		return nil, err
+	}
+	filtered, err := getFilteredCodeSetIfNeeded(ctx, codeSet)
+	if err != nil {
+		return nil, err
+	}
+	setsMu.Lock()
+	cachedOpcodeSets[index] = codeSet
+	setsMu.Unlock()
+	return filtered, nil
+}

internal/encoder/context.go

@@ -0,0 +1,105 @@
+package encoder
+
+import (
+	"context"
+	"sync"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+type compileContext struct {
+	opcodeIndex       uint32
+	ptrIndex          int
+	indent            uint32
+	escapeKey         bool
+	structTypeToCodes map[uintptr]Opcodes
+	recursiveCodes    *Opcodes
+}
+
+func (c *compileContext) incIndent() {
+	c.indent++
+}
+
+func (c *compileContext) decIndent() {
+	c.indent--
+}
+
+func (c *compileContext) incIndex() {
+	c.incOpcodeIndex()
+	c.incPtrIndex()
+}
+
+func (c *compileContext) decIndex() {
+	c.decOpcodeIndex()
+	c.decPtrIndex()
+}
+
+func (c *compileContext) incOpcodeIndex() {
+	c.opcodeIndex++
+}
+
+func (c *compileContext) decOpcodeIndex() {
+	c.opcodeIndex--
+}
+
+func (c *compileContext) incPtrIndex() {
+	c.ptrIndex++
+}
+
+func (c *compileContext) decPtrIndex() {
+	c.ptrIndex--
+}
+
+const (
+	bufSize = 1024
+)
+
+var (
+	runtimeContextPool = sync.Pool{
+		New: func() interface{} {
+			return &RuntimeContext{
+				Buf:      make([]byte, 0, bufSize),
+				Ptrs:     make([]uintptr, 128),
+				KeepRefs: make([]unsafe.Pointer, 0, 8),
+				Option:   &Option{},
+			}
+		},
+	}
+)
+
+type RuntimeContext struct {
+	Context    context.Context
+	Buf        []byte
+	MarshalBuf []byte
+	Ptrs       []uintptr
+	KeepRefs   []unsafe.Pointer
+	SeenPtr    []uintptr
+	BaseIndent uint32
+	Prefix     []byte
+	IndentStr  []byte
+	Option     *Option
+}
+
+func (c *RuntimeContext) Init(p uintptr, codelen int) {
+	if len(c.Ptrs) < codelen {
+		c.Ptrs = make([]uintptr, codelen)
+	}
+	c.Ptrs[0] = p
+	c.KeepRefs = c.KeepRefs[:0]
+	c.SeenPtr = c.SeenPtr[:0]
+	c.BaseIndent = 0
+}
+
+func (c *RuntimeContext) Ptr() uintptr {
+	header := (*runtime.SliceHeader)(unsafe.Pointer(&c.Ptrs))
+	return uintptr(header.Data)
+}
+
+func TakeRuntimeContext() *RuntimeContext {
+	return runtimeContextPool.Get().(*RuntimeContext)
+}
+
+func ReleaseRuntimeContext(ctx *RuntimeContext) {
+	runtimeContextPool.Put(ctx)
+}

internal/encoder/decode_rune.go

@@ -0,0 +1,126 @@
+package encoder
+
+import "unicode/utf8"
+
+const (
+	// The default lowest and highest continuation byte.
+	locb = 128 //0b10000000
+	hicb = 191 //0b10111111
+
+	// These names of these constants are chosen to give nice alignment in the
+	// table below. The first nibble is an index into acceptRanges or F for
+	// special one-byte cases. The second nibble is the Rune length or the
+	// Status for the special one-byte case.
+	xx = 0xF1 // invalid: size 1
+	as = 0xF0 // ASCII: size 1
+	s1 = 0x02 // accept 0, size 2
+	s2 = 0x13 // accept 1, size 3
+	s3 = 0x03 // accept 0, size 3
+	s4 = 0x23 // accept 2, size 3
+	s5 = 0x34 // accept 3, size 4
+	s6 = 0x04 // accept 0, size 4
+	s7 = 0x44 // accept 4, size 4
+)
+
+// first is information about the first byte in a UTF-8 sequence.
+var first = [256]uint8{
+	//   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x00-0x0F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x10-0x1F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x20-0x2F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x30-0x3F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x40-0x4F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x50-0x5F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x60-0x6F
+	as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, as, // 0x70-0x7F
+	//   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
+	xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, // 0x80-0x8F
+	xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, // 0x90-0x9F
+	xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, // 0xA0-0xAF
+	xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, // 0xB0-0xBF
+	xx, xx, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, // 0xC0-0xCF
+	s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, s1, // 0xD0-0xDF
+	s2, s3, s3, s3, s3, s3, s3, s3, s3, s3, s3, s3, s3, s4, s3, s3, // 0xE0-0xEF
+	s5, s6, s6, s6, s7, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, xx, // 0xF0-0xFF
+}
+
+const (
+	lineSep      = byte(168) //'\u2028'
+	paragraphSep = byte(169) //'\u2029'
+)
+
+type decodeRuneState int
+
+const (
+	validUTF8State decodeRuneState = iota
+	runeErrorState
+	lineSepState
+	paragraphSepState
+)
+
+func decodeRuneInString(s string) (decodeRuneState, int) {
+	n := len(s)
+	s0 := s[0]
+	x := first[s0]
+	if x >= as {
+		// The following code simulates an additional check for x == xx and
+		// handling the ASCII and invalid cases accordingly. This mask-and-or
+		// approach prevents an additional branch.
+		mask := rune(x) << 31 >> 31 // Create 0x0000 or 0xFFFF.
+		if rune(s[0])&^mask|utf8.RuneError&mask == utf8.RuneError {
+			return runeErrorState, 1
+		}
+		return validUTF8State, 1
+	}
+	sz := int(x & 7)
+	if n < sz {
+		return runeErrorState, 1
+	}
+	s1 := s[1]
+	switch x >> 4 {
+	case 0:
+		if s1 < locb || hicb < s1 {
+			return runeErrorState, 1
+		}
+	case 1:
+		if s1 < 0xA0 || hicb < s1 {
+			return runeErrorState, 1
+		}
+	case 2:
+		if s1 < locb || 0x9F < s1 {
+			return runeErrorState, 1
+		}
+	case 3:
+		if s1 < 0x90 || hicb < s1 {
+			return runeErrorState, 1
+		}
+	case 4:
+		if s1 < locb || 0x8F < s1 {
+			return runeErrorState, 1
+		}
+	}
+	if sz <= 2 {
+		return validUTF8State, 2
+	}
+	s2 := s[2]
+	if s2 < locb || hicb < s2 {
+		return runeErrorState, 1
+	}
+	if sz <= 3 {
+		// separator character prefixes: [2]byte{226, 128}
+		if s0 == 226 && s1 == 128 {
+			switch s2 {
+			case lineSep:
+				return lineSepState, 3
+			case paragraphSep:
+				return paragraphSepState, 3
+			}
+		}
+		return validUTF8State, 3
+	}
+	s3 := s[3]
+	if s3 < locb || hicb < s3 {
+		return runeErrorState, 1
+	}
+	return validUTF8State, 4
+}

internal/encoder/encode_opcode_test.go

@@ -0,0 +1,20 @@
+package encoder
+
+import (
+	"testing"
+	"unsafe"
+)
+
+func TestDumpOpcode(t *testing.T) {
+	ctx := TakeRuntimeContext()
+	defer ReleaseRuntimeContext(ctx)
+	var v interface{} = 1
+	header := (*emptyInterface)(unsafe.Pointer(&v))
+	typ := header.typ
+	typeptr := uintptr(unsafe.Pointer(typ))
+	codeSet, err := CompileToGetCodeSet(ctx, typeptr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	codeSet.EscapeKeyCode.Dump()
+}

internal/encoder/encoder.go

@@ -0,0 +1,601 @@
+package encoder
+
+import (
+	"bytes"
+	"encoding"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"math"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/errors"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+func (t OpType) IsMultipleOpHead() bool {
+	switch t {
+	case OpStructHead:
+		return true
+	case OpStructHeadSlice:
+		return true
+	case OpStructHeadArray:
+		return true
+	case OpStructHeadMap:
+		return true
+	case OpStructHeadStruct:
+		return true
+	case OpStructHeadOmitEmpty:
+		return true
+	case OpStructHeadOmitEmptySlice:
+		return true
+	case OpStructHeadOmitEmptyArray:
+		return true
+	case OpStructHeadOmitEmptyMap:
+		return true
+	case OpStructHeadOmitEmptyStruct:
+		return true
+	case OpStructHeadSlicePtr:
+		return true
+	case OpStructHeadOmitEmptySlicePtr:
+		return true
+	case OpStructHeadArrayPtr:
+		return true
+	case OpStructHeadOmitEmptyArrayPtr:
+		return true
+	case OpStructHeadMapPtr:
+		return true
+	case OpStructHeadOmitEmptyMapPtr:
+		return true
+	}
+	return false
+}
+
+func (t OpType) IsMultipleOpField() bool {
+	switch t {
+	case OpStructField:
+		return true
+	case OpStructFieldSlice:
+		return true
+	case OpStructFieldArray:
+		return true
+	case OpStructFieldMap:
+		return true
+	case OpStructFieldStruct:
+		return true
+	case OpStructFieldOmitEmpty:
+		return true
+	case OpStructFieldOmitEmptySlice:
+		return true
+	case OpStructFieldOmitEmptyArray:
+		return true
+	case OpStructFieldOmitEmptyMap:
+		return true
+	case OpStructFieldOmitEmptyStruct:
+		return true
+	case OpStructFieldSlicePtr:
+		return true
+	case OpStructFieldOmitEmptySlicePtr:
+		return true
+	case OpStructFieldArrayPtr:
+		return true
+	case OpStructFieldOmitEmptyArrayPtr:
+		return true
+	case OpStructFieldMapPtr:
+		return true
+	case OpStructFieldOmitEmptyMapPtr:
+		return true
+	}
+	return false
+}
+
+type OpcodeSet struct {
+	Type                     *runtime.Type
+	NoescapeKeyCode          *Opcode
+	EscapeKeyCode            *Opcode
+	InterfaceNoescapeKeyCode *Opcode
+	InterfaceEscapeKeyCode   *Opcode
+	CodeLength               int
+	EndCode                  *Opcode
+	Code                     Code
+	QueryCache               map[string]*OpcodeSet
+	cacheMu                  sync.RWMutex
+}
+
+func (s *OpcodeSet) getQueryCache(hash string) *OpcodeSet {
+	s.cacheMu.RLock()
+	codeSet := s.QueryCache[hash]
+	s.cacheMu.RUnlock()
+	return codeSet
+}
+
+func (s *OpcodeSet) setQueryCache(hash string, codeSet *OpcodeSet) {
+	s.cacheMu.Lock()
+	s.QueryCache[hash] = codeSet
+	s.cacheMu.Unlock()
+}
+
+type CompiledCode struct {
+	Code    *Opcode
+	Linked  bool // whether recursive code already have linked
+	CurLen  uintptr
+	NextLen uintptr
+}
+
+const StartDetectingCyclesAfter = 1000
+
+func Load(base uintptr, idx uintptr) uintptr {
+	addr := base + idx
+	return **(**uintptr)(unsafe.Pointer(&addr))
+}
+
+func Store(base uintptr, idx uintptr, p uintptr) {
+	addr := base + idx
+	**(**uintptr)(unsafe.Pointer(&addr)) = p
+}
+
+func LoadNPtr(base uintptr, idx uintptr, ptrNum int) uintptr {
+	addr := base + idx
+	p := **(**uintptr)(unsafe.Pointer(&addr))
+	if p == 0 {
+		return 0
+	}
+	return PtrToPtr(p)
+	/*
+		for i := 0; i < ptrNum; i++ {
+			if p == 0 {
+				return p
+			}
+			p = PtrToPtr(p)
+		}
+		return p
+	*/
+}
+
+func PtrToUint64(p uintptr) uint64              { return **(**uint64)(unsafe.Pointer(&p)) }
+func PtrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
+func PtrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
+func PtrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
+func PtrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
+func PtrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
+func PtrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
+func PtrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
+func PtrToPtr(p uintptr) uintptr {
+	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
+}
+func PtrToNPtr(p uintptr, ptrNum int) uintptr {
+	for i := 0; i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = PtrToPtr(p)
+	}
+	return p
+}
+
+func PtrToUnsafePtr(p uintptr) unsafe.Pointer {
+	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
+}
+func PtrToInterface(code *Opcode, p uintptr) interface{} {
+	return *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+}
+
+func ErrUnsupportedValue(code *Opcode, ptr uintptr) *errors.UnsupportedValueError {
+	v := *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&ptr)),
+	}))
+	return &errors.UnsupportedValueError{
+		Value: reflect.ValueOf(v),
+		Str:   fmt.Sprintf("encountered a cycle via %s", code.Type),
+	}
+}
+
+func ErrUnsupportedFloat(v float64) *errors.UnsupportedValueError {
+	return &errors.UnsupportedValueError{
+		Value: reflect.ValueOf(v),
+		Str:   strconv.FormatFloat(v, 'g', -1, 64),
+	}
+}
+
+func ErrMarshalerWithCode(code *Opcode, err error) *errors.MarshalerError {
+	return &errors.MarshalerError{
+		Type: runtime.RType2Type(code.Type),
+		Err:  err,
+	}
+}
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+type MapItem struct {
+	Key   []byte
+	Value []byte
+}
+
+type Mapslice struct {
+	Items []MapItem
+}
+
+func (m *Mapslice) Len() int {
+	return len(m.Items)
+}
+
+func (m *Mapslice) Less(i, j int) bool {
+	return bytes.Compare(m.Items[i].Key, m.Items[j].Key) < 0
+}
+
+func (m *Mapslice) Swap(i, j int) {
+	m.Items[i], m.Items[j] = m.Items[j], m.Items[i]
+}
+
+//nolint:structcheck,unused
+type mapIter struct {
+	key         unsafe.Pointer
+	elem        unsafe.Pointer
+	t           unsafe.Pointer
+	h           unsafe.Pointer
+	buckets     unsafe.Pointer
+	bptr        unsafe.Pointer
+	overflow    unsafe.Pointer
+	oldoverflow unsafe.Pointer
+	startBucket uintptr
+	offset      uint8
+	wrapped     bool
+	B           uint8
+	i           uint8
+	bucket      uintptr
+	checkBucket uintptr
+}
+
+type MapContext struct {
+	Start int
+	First int
+	Idx   int
+	Slice *Mapslice
+	Buf   []byte
+	Len   int
+	Iter  mapIter
+}
+
+var mapContextPool = sync.Pool{
+	New: func() interface{} {
+		return &MapContext{
+			Slice: &Mapslice{},
+		}
+	},
+}
+
+func NewMapContext(mapLen int, unorderedMap bool) *MapContext {
+	ctx := mapContextPool.Get().(*MapContext)
+	if !unorderedMap {
+		if len(ctx.Slice.Items) < mapLen {
+			ctx.Slice.Items = make([]MapItem, mapLen)
+		} else {
+			ctx.Slice.Items = ctx.Slice.Items[:mapLen]
+		}
+	}
+	ctx.Buf = ctx.Buf[:0]
+	ctx.Iter = mapIter{}
+	ctx.Idx = 0
+	ctx.Len = mapLen
+	return ctx
+}
+
+func ReleaseMapContext(c *MapContext) {
+	mapContextPool.Put(c)
+}
+
+//go:linkname MapIterInit runtime.mapiterinit
+//go:noescape
+func MapIterInit(mapType *runtime.Type, m unsafe.Pointer, it *mapIter)
+
+//go:linkname MapIterKey reflect.mapiterkey
+//go:noescape
+func MapIterKey(it *mapIter) unsafe.Pointer
+
+//go:linkname MapIterNext reflect.mapiternext
+//go:noescape
+func MapIterNext(it *mapIter)
+
+//go:linkname MapLen reflect.maplen
+//go:noescape
+func MapLen(m unsafe.Pointer) int
+
+func AppendByteSlice(_ *RuntimeContext, b []byte, src []byte) []byte {
+	if src == nil {
+		return append(b, `null`...)
+	}
+	encodedLen := base64.StdEncoding.EncodedLen(len(src))
+	b = append(b, '"')
+	pos := len(b)
+	remainLen := cap(b[pos:])
+	var buf []byte
+	if remainLen > encodedLen {
+		buf = b[pos : pos+encodedLen]
+	} else {
+		buf = make([]byte, encodedLen)
+	}
+	base64.StdEncoding.Encode(buf, src)
+	return append(append(b, buf...), '"')
+}
+
+func AppendFloat32(_ *RuntimeContext, b []byte, v float32) []byte {
+	f64 := float64(v)
+	abs := math.Abs(f64)
+	fmt := byte('f')
+	// Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right.
+	if abs != 0 {
+		f32 := float32(abs)
+		if f32 < 1e-6 || f32 >= 1e21 {
+			fmt = 'e'
+		}
+	}
+	return strconv.AppendFloat(b, f64, fmt, -1, 32)
+}
+
+func AppendFloat64(_ *RuntimeContext, b []byte, v float64) []byte {
+	abs := math.Abs(v)
+	fmt := byte('f')
+	// Note: Must use float32 comparisons for underlying float32 value to get precise cutoffs right.
+	if abs != 0 {
+		if abs < 1e-6 || abs >= 1e21 {
+			fmt = 'e'
+		}
+	}
+	return strconv.AppendFloat(b, v, fmt, -1, 64)
+}
+
+func AppendBool(_ *RuntimeContext, b []byte, v bool) []byte {
+	if v {
+		return append(b, "true"...)
+	}
+	return append(b, "false"...)
+}
+
+var (
+	floatTable = [256]bool{
+		'0': true,
+		'1': true,
+		'2': true,
+		'3': true,
+		'4': true,
+		'5': true,
+		'6': true,
+		'7': true,
+		'8': true,
+		'9': true,
+		'.': true,
+		'e': true,
+		'E': true,
+		'+': true,
+		'-': true,
+	}
+)
+
+func AppendNumber(_ *RuntimeContext, b []byte, n json.Number) ([]byte, error) {
+	if len(n) == 0 {
+		return append(b, '0'), nil
+	}
+	for i := 0; i < len(n); i++ {
+		if !floatTable[n[i]] {
+			return nil, fmt.Errorf("json: invalid number literal %q", n)
+		}
+	}
+	b = append(b, n...)
+	return b, nil
+}
+
+func AppendMarshalJSON(ctx *RuntimeContext, code *Opcode, b []byte, v interface{}) ([]byte, error) {
+	rv := reflect.ValueOf(v) // convert by dynamic interface type
+	if (code.Flags & AddrForMarshalerFlags) != 0 {
+		if rv.CanAddr() {
+			rv = rv.Addr()
+		} else {
+			newV := reflect.New(rv.Type())
+			newV.Elem().Set(rv)
+			rv = newV
+		}
+	}
+
+	if rv.Kind() == reflect.Ptr && rv.IsNil() {
+		return AppendNull(ctx, b), nil
+	}
+
+	v = rv.Interface()
+	var bb []byte
+	if (code.Flags & MarshalerContextFlags) != 0 {
+		marshaler, ok := v.(marshalerContext)
+		if !ok {
+			return AppendNull(ctx, b), nil
+		}
+		stdctx := ctx.Option.Context
+		if ctx.Option.Flag&FieldQueryOption != 0 {
+			stdctx = SetFieldQueryToContext(stdctx, code.FieldQuery)
+		}
+		b, err := marshaler.MarshalJSON(stdctx)
+		if err != nil {
+			return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+		}
+		bb = b
+	} else {
+		marshaler, ok := v.(json.Marshaler)
+		if !ok {
+			return AppendNull(ctx, b), nil
+		}
+		b, err := marshaler.MarshalJSON()
+		if err != nil {
+			return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+		}
+		bb = b
+	}
+	marshalBuf := ctx.MarshalBuf[:0]
+	marshalBuf = append(append(marshalBuf, bb...), nul)
+	compactedBuf, err := compact(b, marshalBuf, (ctx.Option.Flag&HTMLEscapeOption) != 0)
+	if err != nil {
+		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+	}
+	ctx.MarshalBuf = marshalBuf
+	return compactedBuf, nil
+}
+
+func AppendMarshalJSONIndent(ctx *RuntimeContext, code *Opcode, b []byte, v interface{}) ([]byte, error) {
+	rv := reflect.ValueOf(v) // convert by dynamic interface type
+	if (code.Flags & AddrForMarshalerFlags) != 0 {
+		if rv.CanAddr() {
+			rv = rv.Addr()
+		} else {
+			newV := reflect.New(rv.Type())
+			newV.Elem().Set(rv)
+			rv = newV
+		}
+	}
+	v = rv.Interface()
+	var bb []byte
+	if (code.Flags & MarshalerContextFlags) != 0 {
+		marshaler, ok := v.(marshalerContext)
+		if !ok {
+			return AppendNull(ctx, b), nil
+		}
+		b, err := marshaler.MarshalJSON(ctx.Option.Context)
+		if err != nil {
+			return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+		}
+		bb = b
+	} else {
+		marshaler, ok := v.(json.Marshaler)
+		if !ok {
+			return AppendNull(ctx, b), nil
+		}
+		b, err := marshaler.MarshalJSON()
+		if err != nil {
+			return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+		}
+		bb = b
+	}
+	marshalBuf := ctx.MarshalBuf[:0]
+	marshalBuf = append(append(marshalBuf, bb...), nul)
+	indentedBuf, err := doIndent(
+		b,
+		marshalBuf,
+		string(ctx.Prefix)+strings.Repeat(string(ctx.IndentStr), int(ctx.BaseIndent+code.Indent)),
+		string(ctx.IndentStr),
+		(ctx.Option.Flag&HTMLEscapeOption) != 0,
+	)
+	if err != nil {
+		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+	}
+	ctx.MarshalBuf = marshalBuf
+	return indentedBuf, nil
+}
+
+func AppendMarshalText(ctx *RuntimeContext, code *Opcode, b []byte, v interface{}) ([]byte, error) {
+	rv := reflect.ValueOf(v) // convert by dynamic interface type
+	if (code.Flags & AddrForMarshalerFlags) != 0 {
+		if rv.CanAddr() {
+			rv = rv.Addr()
+		} else {
+			newV := reflect.New(rv.Type())
+			newV.Elem().Set(rv)
+			rv = newV
+		}
+	}
+	v = rv.Interface()
+	marshaler, ok := v.(encoding.TextMarshaler)
+	if !ok {
+		return AppendNull(ctx, b), nil
+	}
+	bytes, err := marshaler.MarshalText()
+	if err != nil {
+		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+	}
+	return AppendString(ctx, b, *(*string)(unsafe.Pointer(&bytes))), nil
+}
+
+func AppendMarshalTextIndent(ctx *RuntimeContext, code *Opcode, b []byte, v interface{}) ([]byte, error) {
+	rv := reflect.ValueOf(v) // convert by dynamic interface type
+	if (code.Flags & AddrForMarshalerFlags) != 0 {
+		if rv.CanAddr() {
+			rv = rv.Addr()
+		} else {
+			newV := reflect.New(rv.Type())
+			newV.Elem().Set(rv)
+			rv = newV
+		}
+	}
+	v = rv.Interface()
+	marshaler, ok := v.(encoding.TextMarshaler)
+	if !ok {
+		return AppendNull(ctx, b), nil
+	}
+	bytes, err := marshaler.MarshalText()
+	if err != nil {
+		return nil, &errors.MarshalerError{Type: reflect.TypeOf(v), Err: err}
+	}
+	return AppendString(ctx, b, *(*string)(unsafe.Pointer(&bytes))), nil
+}
+
+func AppendNull(_ *RuntimeContext, b []byte) []byte {
+	return append(b, "null"...)
+}
+
+func AppendComma(_ *RuntimeContext, b []byte) []byte {
+	return append(b, ',')
+}
+
+func AppendCommaIndent(_ *RuntimeContext, b []byte) []byte {
+	return append(b, ',', '\n')
+}
+
+func AppendStructEnd(_ *RuntimeContext, b []byte) []byte {
+	return append(b, '}', ',')
+}
+
+func AppendStructEndIndent(ctx *RuntimeContext, code *Opcode, b []byte) []byte {
+	b = append(b, '\n')
+	b = append(b, ctx.Prefix...)
+	indentNum := ctx.BaseIndent + code.Indent - 1
+	for i := uint32(0); i < indentNum; i++ {
+		b = append(b, ctx.IndentStr...)
+	}
+	return append(b, '}', ',', '\n')
+}
+
+func AppendIndent(ctx *RuntimeContext, b []byte, indent uint32) []byte {
+	b = append(b, ctx.Prefix...)
+	indentNum := ctx.BaseIndent + indent
+	for i := uint32(0); i < indentNum; i++ {
+		b = append(b, ctx.IndentStr...)
+	}
+	return b
+}
+
+func IsNilForMarshaler(v interface{}) bool {
+	rv := reflect.ValueOf(v)
+	switch rv.Kind() {
+	case reflect.Bool:
+		return !rv.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return rv.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return rv.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return math.Float64bits(rv.Float()) == 0
+	case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Func:
+		return rv.IsNil()
+	case reflect.Slice:
+		return rv.IsNil() || rv.Len() == 0
+	case reflect.String:
+		return rv.Len() == 0
+	}
+	return false
+}

internal/encoder/indent.go

@@ -0,0 +1,211 @@
+package encoder
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/goccy/go-json/internal/errors"
+)
+
+func takeIndentSrcRuntimeContext(src []byte) (*RuntimeContext, []byte) {
+	ctx := TakeRuntimeContext()
+	buf := ctx.Buf[:0]
+	buf = append(append(buf, src...), nul)
+	ctx.Buf = buf
+	return ctx, buf
+}
+
+func Indent(buf *bytes.Buffer, src []byte, prefix, indentStr string) error {
+	if len(src) == 0 {
+		return errors.ErrUnexpectedEndOfJSON("", 0)
+	}
+
+	srcCtx, srcBuf := takeIndentSrcRuntimeContext(src)
+	dstCtx := TakeRuntimeContext()
+	dst := dstCtx.Buf[:0]
+
+	dst, err := indentAndWrite(buf, dst, srcBuf, prefix, indentStr)
+	if err != nil {
+		ReleaseRuntimeContext(srcCtx)
+		ReleaseRuntimeContext(dstCtx)
+		return err
+	}
+	dstCtx.Buf = dst
+	ReleaseRuntimeContext(srcCtx)
+	ReleaseRuntimeContext(dstCtx)
+	return nil
+}
+
+func indentAndWrite(buf *bytes.Buffer, dst []byte, src []byte, prefix, indentStr string) ([]byte, error) {
+	dst, err := doIndent(dst, src, prefix, indentStr, false)
+	if err != nil {
+		return nil, err
+	}
+	if _, err := buf.Write(dst); err != nil {
+		return nil, err
+	}
+	return dst, nil
+}
+
+func doIndent(dst, src []byte, prefix, indentStr string, escape bool) ([]byte, error) {
+	buf, cursor, err := indentValue(dst, src, 0, 0, []byte(prefix), []byte(indentStr), escape)
+	if err != nil {
+		return nil, err
+	}
+	if err := validateEndBuf(src, cursor); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func indentValue(
+	dst []byte,
+	src []byte,
+	indentNum int,
+	cursor int64,
+	prefix []byte,
+	indentBytes []byte,
+	escape bool) ([]byte, int64, error) {
+	for {
+		switch src[cursor] {
+		case ' ', '\t', '\n', '\r':
+			cursor++
+			continue
+		case '{':
+			return indentObject(dst, src, indentNum, cursor, prefix, indentBytes, escape)
+		case '}':
+			return nil, 0, errors.ErrSyntax("unexpected character '}'", cursor)
+		case '[':
+			return indentArray(dst, src, indentNum, cursor, prefix, indentBytes, escape)
+		case ']':
+			return nil, 0, errors.ErrSyntax("unexpected character ']'", cursor)
+		case '"':
+			return compactString(dst, src, cursor, escape)
+		case '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9':
+			return compactNumber(dst, src, cursor)
+		case 't':
+			return compactTrue(dst, src, cursor)
+		case 'f':
+			return compactFalse(dst, src, cursor)
+		case 'n':
+			return compactNull(dst, src, cursor)
+		default:
+			return nil, 0, errors.ErrSyntax(fmt.Sprintf("unexpected character '%c'", src[cursor]), cursor)
+		}
+	}
+}
+
+func indentObject(
+	dst []byte,
+	src []byte,
+	indentNum int,
+	cursor int64,
+	prefix []byte,
+	indentBytes []byte,
+	escape bool) ([]byte, int64, error) {
+	if src[cursor] == '{' {
+		dst = append(dst, '{')
+	} else {
+		return nil, 0, errors.ErrExpected("expected { character for object value", cursor)
+	}
+	cursor = skipWhiteSpace(src, cursor+1)
+	if src[cursor] == '}' {
+		dst = append(dst, '}')
+		return dst, cursor + 1, nil
+	}
+	indentNum++
+	var err error
+	for {
+		dst = append(append(dst, '\n'), prefix...)
+		for i := 0; i < indentNum; i++ {
+			dst = append(dst, indentBytes...)
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		dst, cursor, err = compactString(dst, src, cursor, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		if src[cursor] != ':' {
+			return nil, 0, errors.ErrSyntax(
+				fmt.Sprintf("invalid character '%c' after object key", src[cursor]),
+				cursor+1,
+			)
+		}
+		dst = append(dst, ':', ' ')
+		dst, cursor, err = indentValue(dst, src, indentNum, cursor+1, prefix, indentBytes, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		switch src[cursor] {
+		case '}':
+			dst = append(append(dst, '\n'), prefix...)
+			for i := 0; i < indentNum-1; i++ {
+				dst = append(dst, indentBytes...)
+			}
+			dst = append(dst, '}')
+			cursor++
+			return dst, cursor, nil
+		case ',':
+			dst = append(dst, ',')
+		default:
+			return nil, 0, errors.ErrSyntax(
+				fmt.Sprintf("invalid character '%c' after object key:value pair", src[cursor]),
+				cursor+1,
+			)
+		}
+		cursor++
+	}
+}
+
+func indentArray(
+	dst []byte,
+	src []byte,
+	indentNum int,
+	cursor int64,
+	prefix []byte,
+	indentBytes []byte,
+	escape bool) ([]byte, int64, error) {
+	if src[cursor] == '[' {
+		dst = append(dst, '[')
+	} else {
+		return nil, 0, errors.ErrExpected("expected [ character for array value", cursor)
+	}
+	cursor = skipWhiteSpace(src, cursor+1)
+	if src[cursor] == ']' {
+		dst = append(dst, ']')
+		return dst, cursor + 1, nil
+	}
+	indentNum++
+	var err error
+	for {
+		dst = append(append(dst, '\n'), prefix...)
+		for i := 0; i < indentNum; i++ {
+			dst = append(dst, indentBytes...)
+		}
+		dst, cursor, err = indentValue(dst, src, indentNum, cursor, prefix, indentBytes, escape)
+		if err != nil {
+			return nil, 0, err
+		}
+		cursor = skipWhiteSpace(src, cursor)
+		switch src[cursor] {
+		case ']':
+			dst = append(append(dst, '\n'), prefix...)
+			for i := 0; i < indentNum-1; i++ {
+				dst = append(dst, indentBytes...)
+			}
+			dst = append(dst, ']')
+			cursor++
+			return dst, cursor, nil
+		case ',':
+			dst = append(dst, ',')
+		default:
+			return nil, 0, errors.ErrSyntax(
+				fmt.Sprintf("invalid character '%c' after array value", src[cursor]),
+				cursor+1,
+			)
+		}
+		cursor++
+	}
+}

internal/encoder/int.go

@@ -0,0 +1,176 @@
+// This files's processing codes are inspired by https://github.com/segmentio/encoding.
+// The license notation is as follows.
+//
+// # MIT License
+//
+// Copyright (c) 2019 Segment.io, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+package encoder
+
+import (
+	"unsafe"
+)
+
+var endianness int
+
+func init() {
+	var b [2]byte
+	*(*uint16)(unsafe.Pointer(&b)) = uint16(0xABCD)
+
+	switch b[0] {
+	case 0xCD:
+		endianness = 0 // LE
+	case 0xAB:
+		endianness = 1 // BE
+	default:
+		panic("could not determine endianness")
+	}
+}
+
+// "00010203...96979899" cast to []uint16
+var intLELookup = [100]uint16{
+	0x3030, 0x3130, 0x3230, 0x3330, 0x3430, 0x3530, 0x3630, 0x3730, 0x3830, 0x3930,
+	0x3031, 0x3131, 0x3231, 0x3331, 0x3431, 0x3531, 0x3631, 0x3731, 0x3831, 0x3931,
+	0x3032, 0x3132, 0x3232, 0x3332, 0x3432, 0x3532, 0x3632, 0x3732, 0x3832, 0x3932,
+	0x3033, 0x3133, 0x3233, 0x3333, 0x3433, 0x3533, 0x3633, 0x3733, 0x3833, 0x3933,
+	0x3034, 0x3134, 0x3234, 0x3334, 0x3434, 0x3534, 0x3634, 0x3734, 0x3834, 0x3934,
+	0x3035, 0x3135, 0x3235, 0x3335, 0x3435, 0x3535, 0x3635, 0x3735, 0x3835, 0x3935,
+	0x3036, 0x3136, 0x3236, 0x3336, 0x3436, 0x3536, 0x3636, 0x3736, 0x3836, 0x3936,
+	0x3037, 0x3137, 0x3237, 0x3337, 0x3437, 0x3537, 0x3637, 0x3737, 0x3837, 0x3937,
+	0x3038, 0x3138, 0x3238, 0x3338, 0x3438, 0x3538, 0x3638, 0x3738, 0x3838, 0x3938,
+	0x3039, 0x3139, 0x3239, 0x3339, 0x3439, 0x3539, 0x3639, 0x3739, 0x3839, 0x3939,
+}
+
+var intBELookup = [100]uint16{
+	0x3030, 0x3031, 0x3032, 0x3033, 0x3034, 0x3035, 0x3036, 0x3037, 0x3038, 0x3039,
+	0x3130, 0x3131, 0x3132, 0x3133, 0x3134, 0x3135, 0x3136, 0x3137, 0x3138, 0x3139,
+	0x3230, 0x3231, 0x3232, 0x3233, 0x3234, 0x3235, 0x3236, 0x3237, 0x3238, 0x3239,
+	0x3330, 0x3331, 0x3332, 0x3333, 0x3334, 0x3335, 0x3336, 0x3337, 0x3338, 0x3339,
+	0x3430, 0x3431, 0x3432, 0x3433, 0x3434, 0x3435, 0x3436, 0x3437, 0x3438, 0x3439,
+	0x3530, 0x3531, 0x3532, 0x3533, 0x3534, 0x3535, 0x3536, 0x3537, 0x3538, 0x3539,
+	0x3630, 0x3631, 0x3632, 0x3633, 0x3634, 0x3635, 0x3636, 0x3637, 0x3638, 0x3639,
+	0x3730, 0x3731, 0x3732, 0x3733, 0x3734, 0x3735, 0x3736, 0x3737, 0x3738, 0x3739,
+	0x3830, 0x3831, 0x3832, 0x3833, 0x3834, 0x3835, 0x3836, 0x3837, 0x3838, 0x3839,
+	0x3930, 0x3931, 0x3932, 0x3933, 0x3934, 0x3935, 0x3936, 0x3937, 0x3938, 0x3939,
+}
+
+var intLookup = [2]*[100]uint16{&intLELookup, &intBELookup}
+
+func numMask(numBitSize uint8) uint64 {
+	return 1<<numBitSize - 1
+}
+
+func AppendInt(_ *RuntimeContext, out []byte, p uintptr, code *Opcode) []byte {
+	var u64 uint64
+	switch code.NumBitSize {
+	case 8:
+		u64 = (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		u64 = (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		u64 = (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		u64 = **(**uint64)(unsafe.Pointer(&p))
+	}
+	mask := numMask(code.NumBitSize)
+	n := u64 & mask
+	negative := (u64>>(code.NumBitSize-1))&1 == 1
+	if !negative {
+		if n < 10 {
+			return append(out, byte(n+'0'))
+		} else if n < 100 {
+			u := intLELookup[n]
+			return append(out, byte(u), byte(u>>8))
+		}
+	} else {
+		n = -n & mask
+	}
+
+	lookup := intLookup[endianness]
+
+	var b [22]byte
+	u := (*[11]uint16)(unsafe.Pointer(&b))
+	i := 11
+
+	for n >= 100 {
+		j := n % 100
+		n /= 100
+		i--
+		u[i] = lookup[j]
+	}
+
+	i--
+	u[i] = lookup[n]
+
+	i *= 2 // convert to byte index
+	if n < 10 {
+		i++ // remove leading zero
+	}
+	if negative {
+		i--
+		b[i] = '-'
+	}
+
+	return append(out, b[i:]...)
+}
+
+func AppendUint(_ *RuntimeContext, out []byte, p uintptr, code *Opcode) []byte {
+	var u64 uint64
+	switch code.NumBitSize {
+	case 8:
+		u64 = (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		u64 = (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		u64 = (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		u64 = **(**uint64)(unsafe.Pointer(&p))
+	}
+	mask := numMask(code.NumBitSize)
+	n := u64 & mask
+	if n < 10 {
+		return append(out, byte(n+'0'))
+	} else if n < 100 {
+		u := intLELookup[n]
+		return append(out, byte(u), byte(u>>8))
+	}
+
+	lookup := intLookup[endianness]
+
+	var b [22]byte
+	u := (*[11]uint16)(unsafe.Pointer(&b))
+	i := 11
+
+	for n >= 100 {
+		j := n % 100
+		n /= 100
+		i--
+		u[i] = lookup[j]
+	}
+
+	i--
+	u[i] = lookup[n]
+
+	i *= 2 // convert to byte index
+	if n < 10 {
+		i++ // remove leading zero
+	}
+	return append(out, b[i:]...)
+}

internal/encoder/map112.go

@@ -0,0 +1,9 @@
+//go:build !go1.13
+// +build !go1.13
+
+package encoder
+
+import "unsafe"
+
+//go:linkname MapIterValue reflect.mapitervalue
+func MapIterValue(it *mapIter) unsafe.Pointer

internal/encoder/map113.go

@@ -0,0 +1,9 @@
+//go:build go1.13
+// +build go1.13
+
+package encoder
+
+import "unsafe"
+
+//go:linkname MapIterValue reflect.mapiterelem
+func MapIterValue(it *mapIter) unsafe.Pointer

internal/encoder/opcode.go

@@ -0,0 +1,752 @@
+package encoder
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"strings"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+const uintptrSize = 4 << (^uintptr(0) >> 63)
+
+type OpFlags uint16
+
+const (
+	AnonymousHeadFlags     OpFlags = 1 << 0
+	AnonymousKeyFlags      OpFlags = 1 << 1
+	IndirectFlags          OpFlags = 1 << 2
+	IsTaggedKeyFlags       OpFlags = 1 << 3
+	NilCheckFlags          OpFlags = 1 << 4
+	AddrForMarshalerFlags  OpFlags = 1 << 5
+	IsNextOpPtrTypeFlags   OpFlags = 1 << 6
+	IsNilableTypeFlags     OpFlags = 1 << 7
+	MarshalerContextFlags  OpFlags = 1 << 8
+	NonEmptyInterfaceFlags OpFlags = 1 << 9
+)
+
+type Opcode struct {
+	Op         OpType  // operation type
+	Idx        uint32  // offset to access ptr
+	Next       *Opcode // next opcode
+	End        *Opcode // array/slice/struct/map end
+	NextField  *Opcode // next struct field
+	Key        string  // struct field key
+	Offset     uint32  // offset size from struct header
+	PtrNum     uint8   // pointer number: e.g. double pointer is 2.
+	NumBitSize uint8
+	Flags      OpFlags
+
+	Type       *runtime.Type // go type
+	Jmp        *CompiledCode // for recursive call
+	FieldQuery *FieldQuery   // field query for Interface / MarshalJSON / MarshalText
+	ElemIdx    uint32        // offset to access array/slice elem
+	Length     uint32        // offset to access slice length or array length
+	Indent     uint32        // indent number
+	Size       uint32        // array/slice elem size
+	DisplayIdx uint32        // opcode index
+	DisplayKey string        // key text to display
+}
+
+func (c *Opcode) Validate() error {
+	var prevIdx uint32
+	for code := c; !code.IsEnd(); {
+		if prevIdx != 0 {
+			if code.DisplayIdx != prevIdx+1 {
+				return fmt.Errorf(
+					"invalid index. previous display index is %d but next is %d. dump = %s",
+					prevIdx, code.DisplayIdx, c.Dump(),
+				)
+			}
+		}
+		prevIdx = code.DisplayIdx
+		code = code.IterNext()
+	}
+	return nil
+}
+
+func (c *Opcode) IterNext() *Opcode {
+	if c == nil {
+		return nil
+	}
+	switch c.Op.CodeType() {
+	case CodeArrayElem, CodeSliceElem, CodeMapKey:
+		return c.End
+	default:
+		return c.Next
+	}
+}
+
+func (c *Opcode) IsEnd() bool {
+	if c == nil {
+		return true
+	}
+	return c.Op == OpEnd || c.Op == OpInterfaceEnd || c.Op == OpRecursiveEnd
+}
+
+func (c *Opcode) MaxIdx() uint32 {
+	max := uint32(0)
+	for _, value := range []uint32{
+		c.Idx,
+		c.ElemIdx,
+		c.Length,
+		c.Size,
+	} {
+		if max < value {
+			max = value
+		}
+	}
+	return max
+}
+
+func (c *Opcode) ToHeaderType(isString bool) OpType {
+	switch c.Op {
+	case OpInt:
+		if isString {
+			return OpStructHeadIntString
+		}
+		return OpStructHeadInt
+	case OpIntPtr:
+		if isString {
+			return OpStructHeadIntPtrString
+		}
+		return OpStructHeadIntPtr
+	case OpUint:
+		if isString {
+			return OpStructHeadUintString
+		}
+		return OpStructHeadUint
+	case OpUintPtr:
+		if isString {
+			return OpStructHeadUintPtrString
+		}
+		return OpStructHeadUintPtr
+	case OpFloat32:
+		if isString {
+			return OpStructHeadFloat32String
+		}
+		return OpStructHeadFloat32
+	case OpFloat32Ptr:
+		if isString {
+			return OpStructHeadFloat32PtrString
+		}
+		return OpStructHeadFloat32Ptr
+	case OpFloat64:
+		if isString {
+			return OpStructHeadFloat64String
+		}
+		return OpStructHeadFloat64
+	case OpFloat64Ptr:
+		if isString {
+			return OpStructHeadFloat64PtrString
+		}
+		return OpStructHeadFloat64Ptr
+	case OpString:
+		if isString {
+			return OpStructHeadStringString
+		}
+		return OpStructHeadString
+	case OpStringPtr:
+		if isString {
+			return OpStructHeadStringPtrString
+		}
+		return OpStructHeadStringPtr
+	case OpNumber:
+		if isString {
+			return OpStructHeadNumberString
+		}
+		return OpStructHeadNumber
+	case OpNumberPtr:
+		if isString {
+			return OpStructHeadNumberPtrString
+		}
+		return OpStructHeadNumberPtr
+	case OpBool:
+		if isString {
+			return OpStructHeadBoolString
+		}
+		return OpStructHeadBool
+	case OpBoolPtr:
+		if isString {
+			return OpStructHeadBoolPtrString
+		}
+		return OpStructHeadBoolPtr
+	case OpBytes:
+		return OpStructHeadBytes
+	case OpBytesPtr:
+		return OpStructHeadBytesPtr
+	case OpMap:
+		return OpStructHeadMap
+	case OpMapPtr:
+		c.Op = OpMap
+		return OpStructHeadMapPtr
+	case OpArray:
+		return OpStructHeadArray
+	case OpArrayPtr:
+		c.Op = OpArray
+		return OpStructHeadArrayPtr
+	case OpSlice:
+		return OpStructHeadSlice
+	case OpSlicePtr:
+		c.Op = OpSlice
+		return OpStructHeadSlicePtr
+	case OpMarshalJSON:
+		return OpStructHeadMarshalJSON
+	case OpMarshalJSONPtr:
+		return OpStructHeadMarshalJSONPtr
+	case OpMarshalText:
+		return OpStructHeadMarshalText
+	case OpMarshalTextPtr:
+		return OpStructHeadMarshalTextPtr
+	}
+	return OpStructHead
+}
+
+func (c *Opcode) ToFieldType(isString bool) OpType {
+	switch c.Op {
+	case OpInt:
+		if isString {
+			return OpStructFieldIntString
+		}
+		return OpStructFieldInt
+	case OpIntPtr:
+		if isString {
+			return OpStructFieldIntPtrString
+		}
+		return OpStructFieldIntPtr
+	case OpUint:
+		if isString {
+			return OpStructFieldUintString
+		}
+		return OpStructFieldUint
+	case OpUintPtr:
+		if isString {
+			return OpStructFieldUintPtrString
+		}
+		return OpStructFieldUintPtr
+	case OpFloat32:
+		if isString {
+			return OpStructFieldFloat32String
+		}
+		return OpStructFieldFloat32
+	case OpFloat32Ptr:
+		if isString {
+			return OpStructFieldFloat32PtrString
+		}
+		return OpStructFieldFloat32Ptr
+	case OpFloat64:
+		if isString {
+			return OpStructFieldFloat64String
+		}
+		return OpStructFieldFloat64
+	case OpFloat64Ptr:
+		if isString {
+			return OpStructFieldFloat64PtrString
+		}
+		return OpStructFieldFloat64Ptr
+	case OpString:
+		if isString {
+			return OpStructFieldStringString
+		}
+		return OpStructFieldString
+	case OpStringPtr:
+		if isString {
+			return OpStructFieldStringPtrString
+		}
+		return OpStructFieldStringPtr
+	case OpNumber:
+		if isString {
+			return OpStructFieldNumberString
+		}
+		return OpStructFieldNumber
+	case OpNumberPtr:
+		if isString {
+			return OpStructFieldNumberPtrString
+		}
+		return OpStructFieldNumberPtr
+	case OpBool:
+		if isString {
+			return OpStructFieldBoolString
+		}
+		return OpStructFieldBool
+	case OpBoolPtr:
+		if isString {
+			return OpStructFieldBoolPtrString
+		}
+		return OpStructFieldBoolPtr
+	case OpBytes:
+		return OpStructFieldBytes
+	case OpBytesPtr:
+		return OpStructFieldBytesPtr
+	case OpMap:
+		return OpStructFieldMap
+	case OpMapPtr:
+		c.Op = OpMap
+		return OpStructFieldMapPtr
+	case OpArray:
+		return OpStructFieldArray
+	case OpArrayPtr:
+		c.Op = OpArray
+		return OpStructFieldArrayPtr
+	case OpSlice:
+		return OpStructFieldSlice
+	case OpSlicePtr:
+		c.Op = OpSlice
+		return OpStructFieldSlicePtr
+	case OpMarshalJSON:
+		return OpStructFieldMarshalJSON
+	case OpMarshalJSONPtr:
+		return OpStructFieldMarshalJSONPtr
+	case OpMarshalText:
+		return OpStructFieldMarshalText
+	case OpMarshalTextPtr:
+		return OpStructFieldMarshalTextPtr
+	}
+	return OpStructField
+}
+
+func newOpCode(ctx *compileContext, typ *runtime.Type, op OpType) *Opcode {
+	return newOpCodeWithNext(ctx, typ, op, newEndOp(ctx, typ))
+}
+
+func opcodeOffset(idx int) uint32 {
+	return uint32(idx) * uintptrSize
+}
+
+func getCodeAddrByIdx(head *Opcode, idx uint32) *Opcode {
+	addr := uintptr(unsafe.Pointer(head)) + uintptr(idx)*unsafe.Sizeof(Opcode{})
+	return *(**Opcode)(unsafe.Pointer(&addr))
+}
+
+func copyOpcode(code *Opcode) *Opcode {
+	codeNum := ToEndCode(code).DisplayIdx + 1
+	codeSlice := make([]Opcode, codeNum)
+	head := (*Opcode)((*runtime.SliceHeader)(unsafe.Pointer(&codeSlice)).Data)
+	ptr := head
+	c := code
+	for {
+		*ptr = Opcode{
+			Op:         c.Op,
+			Key:        c.Key,
+			PtrNum:     c.PtrNum,
+			NumBitSize: c.NumBitSize,
+			Flags:      c.Flags,
+			Idx:        c.Idx,
+			Offset:     c.Offset,
+			Type:       c.Type,
+			FieldQuery: c.FieldQuery,
+			DisplayIdx: c.DisplayIdx,
+			DisplayKey: c.DisplayKey,
+			ElemIdx:    c.ElemIdx,
+			Length:     c.Length,
+			Size:       c.Size,
+			Indent:     c.Indent,
+			Jmp:        c.Jmp,
+		}
+		if c.End != nil {
+			ptr.End = getCodeAddrByIdx(head, c.End.DisplayIdx)
+		}
+		if c.NextField != nil {
+			ptr.NextField = getCodeAddrByIdx(head, c.NextField.DisplayIdx)
+		}
+		if c.Next != nil {
+			ptr.Next = getCodeAddrByIdx(head, c.Next.DisplayIdx)
+		}
+		if c.IsEnd() {
+			break
+		}
+		ptr = getCodeAddrByIdx(head, c.DisplayIdx+1)
+		c = c.IterNext()
+	}
+	return head
+}
+
+func setTotalLengthToInterfaceOp(code *Opcode) {
+	for c := code; !c.IsEnd(); {
+		if c.Op == OpInterface || c.Op == OpInterfacePtr {
+			c.Length = uint32(code.TotalLength())
+		}
+		c = c.IterNext()
+	}
+}
+
+func ToEndCode(code *Opcode) *Opcode {
+	c := code
+	for !c.IsEnd() {
+		c = c.IterNext()
+	}
+	return c
+}
+
+func copyToInterfaceOpcode(code *Opcode) *Opcode {
+	copied := copyOpcode(code)
+	c := copied
+	c = ToEndCode(c)
+	c.Idx += uintptrSize
+	c.ElemIdx = c.Idx + uintptrSize
+	c.Length = c.Idx + 2*uintptrSize
+	c.Op = OpInterfaceEnd
+	return copied
+}
+
+func newOpCodeWithNext(ctx *compileContext, typ *runtime.Type, op OpType, next *Opcode) *Opcode {
+	return &Opcode{
+		Op:         op,
+		Idx:        opcodeOffset(ctx.ptrIndex),
+		Next:       next,
+		Type:       typ,
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+	}
+}
+
+func newEndOp(ctx *compileContext, typ *runtime.Type) *Opcode {
+	return newOpCodeWithNext(ctx, typ, OpEnd, nil)
+}
+
+func (c *Opcode) TotalLength() int {
+	var idx int
+	code := c
+	for !code.IsEnd() {
+		maxIdx := int(code.MaxIdx() / uintptrSize)
+		if idx < maxIdx {
+			idx = maxIdx
+		}
+		if code.Op == OpRecursiveEnd {
+			break
+		}
+		code = code.IterNext()
+	}
+	maxIdx := int(code.MaxIdx() / uintptrSize)
+	if idx < maxIdx {
+		idx = maxIdx
+	}
+	return idx + 1
+}
+
+func (c *Opcode) dumpHead(code *Opcode) string {
+	var length uint32
+	if code.Op.CodeType() == CodeArrayHead {
+		length = code.Length
+	} else {
+		length = code.Length / uintptrSize
+	}
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d][elemIdx:%d][length:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+		code.ElemIdx/uintptrSize,
+		length,
+	)
+}
+
+func (c *Opcode) dumpMapHead(code *Opcode) string {
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+	)
+}
+
+func (c *Opcode) dumpMapEnd(code *Opcode) string {
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+	)
+}
+
+func (c *Opcode) dumpElem(code *Opcode) string {
+	var length uint32
+	if code.Op.CodeType() == CodeArrayElem {
+		length = code.Length
+	} else {
+		length = code.Length / uintptrSize
+	}
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d][elemIdx:%d][length:%d][size:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+		code.ElemIdx/uintptrSize,
+		length,
+		code.Size,
+	)
+}
+
+func (c *Opcode) dumpField(code *Opcode) string {
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d][key:%s][offset:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+		code.DisplayKey,
+		code.Offset,
+	)
+}
+
+func (c *Opcode) dumpKey(code *Opcode) string {
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+	)
+}
+
+func (c *Opcode) dumpValue(code *Opcode) string {
+	return fmt.Sprintf(
+		`[%03d]%s%s ([idx:%d])`,
+		code.DisplayIdx,
+		strings.Repeat("-", int(code.Indent)),
+		code.Op,
+		code.Idx/uintptrSize,
+	)
+}
+
+func (c *Opcode) Dump() string {
+	codes := []string{}
+	for code := c; !code.IsEnd(); {
+		switch code.Op.CodeType() {
+		case CodeSliceHead:
+			codes = append(codes, c.dumpHead(code))
+			code = code.Next
+		case CodeMapHead:
+			codes = append(codes, c.dumpMapHead(code))
+			code = code.Next
+		case CodeArrayElem, CodeSliceElem:
+			codes = append(codes, c.dumpElem(code))
+			code = code.End
+		case CodeMapKey:
+			codes = append(codes, c.dumpKey(code))
+			code = code.End
+		case CodeMapValue:
+			codes = append(codes, c.dumpValue(code))
+			code = code.Next
+		case CodeMapEnd:
+			codes = append(codes, c.dumpMapEnd(code))
+			code = code.Next
+		case CodeStructField:
+			codes = append(codes, c.dumpField(code))
+			code = code.Next
+		case CodeStructEnd:
+			codes = append(codes, c.dumpField(code))
+			code = code.Next
+		default:
+			codes = append(codes, fmt.Sprintf(
+				"[%03d]%s%s ([idx:%d])",
+				code.DisplayIdx,
+				strings.Repeat("-", int(code.Indent)),
+				code.Op,
+				code.Idx/uintptrSize,
+			))
+			code = code.Next
+		}
+	}
+	return strings.Join(codes, "\n")
+}
+
+func (c *Opcode) DumpDOT() string {
+	type edge struct {
+		from, to *Opcode
+		label    string
+		weight   int
+	}
+	var edges []edge
+
+	b := &bytes.Buffer{}
+	fmt.Fprintf(b, "digraph \"%p\" {\n", c.Type)
+	fmt.Fprintln(b, "mclimit=1.5;\nrankdir=TD;\nordering=out;\nnode[shape=box];")
+	for code := c; !code.IsEnd(); {
+		label := code.Op.String()
+		fmt.Fprintf(b, "\"%p\" [label=%q];\n", code, label)
+		if p := code.Next; p != nil {
+			edges = append(edges, edge{
+				from:   code,
+				to:     p,
+				label:  "Next",
+				weight: 10,
+			})
+		}
+		if p := code.NextField; p != nil {
+			edges = append(edges, edge{
+				from:   code,
+				to:     p,
+				label:  "NextField",
+				weight: 2,
+			})
+		}
+		if p := code.End; p != nil {
+			edges = append(edges, edge{
+				from:   code,
+				to:     p,
+				label:  "End",
+				weight: 1,
+			})
+		}
+		if p := code.Jmp; p != nil {
+			edges = append(edges, edge{
+				from:   code,
+				to:     p.Code,
+				label:  "Jmp",
+				weight: 1,
+			})
+		}
+
+		switch code.Op.CodeType() {
+		case CodeSliceHead:
+			code = code.Next
+		case CodeMapHead:
+			code = code.Next
+		case CodeArrayElem, CodeSliceElem:
+			code = code.End
+		case CodeMapKey:
+			code = code.End
+		case CodeMapValue:
+			code = code.Next
+		case CodeMapEnd:
+			code = code.Next
+		case CodeStructField:
+			code = code.Next
+		case CodeStructEnd:
+			code = code.Next
+		default:
+			code = code.Next
+		}
+		if code.IsEnd() {
+			fmt.Fprintf(b, "\"%p\" [label=%q];\n", code, code.Op.String())
+		}
+	}
+	sort.Slice(edges, func(i, j int) bool {
+		return edges[i].to.DisplayIdx < edges[j].to.DisplayIdx
+	})
+	for _, e := range edges {
+		fmt.Fprintf(b, "\"%p\" -> \"%p\" [label=%q][weight=%d];\n", e.from, e.to, e.label, e.weight)
+	}
+	fmt.Fprint(b, "}")
+	return b.String()
+}
+
+func newSliceHeaderCode(ctx *compileContext, typ *runtime.Type) *Opcode {
+	idx := opcodeOffset(ctx.ptrIndex)
+	ctx.incPtrIndex()
+	elemIdx := opcodeOffset(ctx.ptrIndex)
+	ctx.incPtrIndex()
+	length := opcodeOffset(ctx.ptrIndex)
+	return &Opcode{
+		Op:         OpSlice,
+		Type:       typ,
+		Idx:        idx,
+		DisplayIdx: ctx.opcodeIndex,
+		ElemIdx:    elemIdx,
+		Length:     length,
+		Indent:     ctx.indent,
+	}
+}
+
+func newSliceElemCode(ctx *compileContext, typ *runtime.Type, head *Opcode, size uintptr) *Opcode {
+	return &Opcode{
+		Op:         OpSliceElem,
+		Type:       typ,
+		Idx:        head.Idx,
+		DisplayIdx: ctx.opcodeIndex,
+		ElemIdx:    head.ElemIdx,
+		Length:     head.Length,
+		Indent:     ctx.indent,
+		Size:       uint32(size),
+	}
+}
+
+func newArrayHeaderCode(ctx *compileContext, typ *runtime.Type, alen int) *Opcode {
+	idx := opcodeOffset(ctx.ptrIndex)
+	ctx.incPtrIndex()
+	elemIdx := opcodeOffset(ctx.ptrIndex)
+	return &Opcode{
+		Op:         OpArray,
+		Type:       typ,
+		Idx:        idx,
+		DisplayIdx: ctx.opcodeIndex,
+		ElemIdx:    elemIdx,
+		Indent:     ctx.indent,
+		Length:     uint32(alen),
+	}
+}
+
+func newArrayElemCode(ctx *compileContext, typ *runtime.Type, head *Opcode, length int, size uintptr) *Opcode {
+	return &Opcode{
+		Op:         OpArrayElem,
+		Type:       typ,
+		Idx:        head.Idx,
+		DisplayIdx: ctx.opcodeIndex,
+		ElemIdx:    head.ElemIdx,
+		Length:     uint32(length),
+		Indent:     ctx.indent,
+		Size:       uint32(size),
+	}
+}
+
+func newMapHeaderCode(ctx *compileContext, typ *runtime.Type) *Opcode {
+	idx := opcodeOffset(ctx.ptrIndex)
+	ctx.incPtrIndex()
+	return &Opcode{
+		Op:         OpMap,
+		Type:       typ,
+		Idx:        idx,
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+	}
+}
+
+func newMapKeyCode(ctx *compileContext, typ *runtime.Type, head *Opcode) *Opcode {
+	return &Opcode{
+		Op:         OpMapKey,
+		Type:       typ,
+		Idx:        head.Idx,
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+	}
+}
+
+func newMapValueCode(ctx *compileContext, typ *runtime.Type, head *Opcode) *Opcode {
+	return &Opcode{
+		Op:         OpMapValue,
+		Type:       typ,
+		Idx:        head.Idx,
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+	}
+}
+
+func newMapEndCode(ctx *compileContext, typ *runtime.Type, head *Opcode) *Opcode {
+	return &Opcode{
+		Op:         OpMapEnd,
+		Type:       typ,
+		Idx:        head.Idx,
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+		Next:       newEndOp(ctx, typ),
+	}
+}
+
+func newRecursiveCode(ctx *compileContext, typ *runtime.Type, jmp *CompiledCode) *Opcode {
+	return &Opcode{
+		Op:         OpRecursive,
+		Type:       typ,
+		Idx:        opcodeOffset(ctx.ptrIndex),
+		Next:       newEndOp(ctx, typ),
+		DisplayIdx: ctx.opcodeIndex,
+		Indent:     ctx.indent,
+		Jmp:        jmp,
+	}
+}

internal/encoder/option.go

@@ -0,0 +1,48 @@
+package encoder
+
+import (
+	"context"
+	"io"
+)
+
+type OptionFlag uint8
+
+const (
+	HTMLEscapeOption OptionFlag = 1 << iota
+	IndentOption
+	UnorderedMapOption
+	DebugOption
+	ColorizeOption
+	ContextOption
+	NormalizeUTF8Option
+	FieldQueryOption
+)
+
+type Option struct {
+	Flag        OptionFlag
+	ColorScheme *ColorScheme
+	Context     context.Context
+	DebugOut    io.Writer
+	DebugDOTOut io.WriteCloser
+}
+
+type EncodeFormat struct {
+	Header string
+	Footer string
+}
+
+type EncodeFormatScheme struct {
+	Int       EncodeFormat
+	Uint      EncodeFormat
+	Float     EncodeFormat
+	Bool      EncodeFormat
+	String    EncodeFormat
+	Binary    EncodeFormat
+	ObjectKey EncodeFormat
+	Null      EncodeFormat
+}
+
+type (
+	ColorScheme = EncodeFormatScheme
+	ColorFormat = EncodeFormat
+)

internal/encoder/optype.go

@@ -0,0 +1,932 @@
+// Code generated by internal/cmd/generator. DO NOT EDIT!
+package encoder
+
+import (
+	"strings"
+)
+
+type CodeType int
+
+const (
+	CodeOp          CodeType = 0
+	CodeArrayHead   CodeType = 1
+	CodeArrayElem   CodeType = 2
+	CodeSliceHead   CodeType = 3
+	CodeSliceElem   CodeType = 4
+	CodeMapHead     CodeType = 5
+	CodeMapKey      CodeType = 6
+	CodeMapValue    CodeType = 7
+	CodeMapEnd      CodeType = 8
+	CodeRecursive   CodeType = 9
+	CodeStructField CodeType = 10
+	CodeStructEnd   CodeType = 11
+)
+
+var opTypeStrings = [400]string{
+	"End",
+	"Interface",
+	"Ptr",
+	"SliceElem",
+	"SliceEnd",
+	"ArrayElem",
+	"ArrayEnd",
+	"MapKey",
+	"MapValue",
+	"MapEnd",
+	"Recursive",
+	"RecursivePtr",
+	"RecursiveEnd",
+	"InterfaceEnd",
+	"Int",
+	"Uint",
+	"Float32",
+	"Float64",
+	"Bool",
+	"String",
+	"Bytes",
+	"Number",
+	"Array",
+	"Map",
+	"Slice",
+	"Struct",
+	"MarshalJSON",
+	"MarshalText",
+	"IntString",
+	"UintString",
+	"Float32String",
+	"Float64String",
+	"BoolString",
+	"StringString",
+	"NumberString",
+	"IntPtr",
+	"UintPtr",
+	"Float32Ptr",
+	"Float64Ptr",
+	"BoolPtr",
+	"StringPtr",
+	"BytesPtr",
+	"NumberPtr",
+	"ArrayPtr",
+	"MapPtr",
+	"SlicePtr",
+	"MarshalJSONPtr",
+	"MarshalTextPtr",
+	"InterfacePtr",
+	"IntPtrString",
+	"UintPtrString",
+	"Float32PtrString",
+	"Float64PtrString",
+	"BoolPtrString",
+	"StringPtrString",
+	"NumberPtrString",
+	"StructHeadInt",
+	"StructHeadOmitEmptyInt",
+	"StructPtrHeadInt",
+	"StructPtrHeadOmitEmptyInt",
+	"StructHeadUint",
+	"StructHeadOmitEmptyUint",
+	"StructPtrHeadUint",
+	"StructPtrHeadOmitEmptyUint",
+	"StructHeadFloat32",
+	"StructHeadOmitEmptyFloat32",
+	"StructPtrHeadFloat32",
+	"StructPtrHeadOmitEmptyFloat32",
+	"StructHeadFloat64",
+	"StructHeadOmitEmptyFloat64",
+	"StructPtrHeadFloat64",
+	"StructPtrHeadOmitEmptyFloat64",
+	"StructHeadBool",
+	"StructHeadOmitEmptyBool",
+	"StructPtrHeadBool",
+	"StructPtrHeadOmitEmptyBool",
+	"StructHeadString",
+	"StructHeadOmitEmptyString",
+	"StructPtrHeadString",
+	"StructPtrHeadOmitEmptyString",
+	"StructHeadBytes",
+	"StructHeadOmitEmptyBytes",
+	"StructPtrHeadBytes",
+	"StructPtrHeadOmitEmptyBytes",
+	"StructHeadNumber",
+	"StructHeadOmitEmptyNumber",
+	"StructPtrHeadNumber",
+	"StructPtrHeadOmitEmptyNumber",
+	"StructHeadArray",
+	"StructHeadOmitEmptyArray",
+	"StructPtrHeadArray",
+	"StructPtrHeadOmitEmptyArray",
+	"StructHeadMap",
+	"StructHeadOmitEmptyMap",
+	"StructPtrHeadMap",
+	"StructPtrHeadOmitEmptyMap",
+	"StructHeadSlice",
+	"StructHeadOmitEmptySlice",
+	"StructPtrHeadSlice",
+	"StructPtrHeadOmitEmptySlice",
+	"StructHeadStruct",
+	"StructHeadOmitEmptyStruct",
+	"StructPtrHeadStruct",
+	"StructPtrHeadOmitEmptyStruct",
+	"StructHeadMarshalJSON",
+	"StructHeadOmitEmptyMarshalJSON",
+	"StructPtrHeadMarshalJSON",
+	"StructPtrHeadOmitEmptyMarshalJSON",
+	"StructHeadMarshalText",
+	"StructHeadOmitEmptyMarshalText",
+	"StructPtrHeadMarshalText",
+	"StructPtrHeadOmitEmptyMarshalText",
+	"StructHeadIntString",
+	"StructHeadOmitEmptyIntString",
+	"StructPtrHeadIntString",
+	"StructPtrHeadOmitEmptyIntString",
+	"StructHeadUintString",
+	"StructHeadOmitEmptyUintString",
+	"StructPtrHeadUintString",
+	"StructPtrHeadOmitEmptyUintString",
+	"StructHeadFloat32String",
+	"StructHeadOmitEmptyFloat32String",
+	"StructPtrHeadFloat32String",
+	"StructPtrHeadOmitEmptyFloat32String",
+	"StructHeadFloat64String",
+	"StructHeadOmitEmptyFloat64String",
+	"StructPtrHeadFloat64String",
+	"StructPtrHeadOmitEmptyFloat64String",
+	"StructHeadBoolString",
+	"StructHeadOmitEmptyBoolString",
+	"StructPtrHeadBoolString",
+	"StructPtrHeadOmitEmptyBoolString",
+	"StructHeadStringString",
+	"StructHeadOmitEmptyStringString",
+	"StructPtrHeadStringString",
+	"StructPtrHeadOmitEmptyStringString",
+	"StructHeadNumberString",
+	"StructHeadOmitEmptyNumberString",
+	"StructPtrHeadNumberString",
+	"StructPtrHeadOmitEmptyNumberString",
+	"StructHeadIntPtr",
+	"StructHeadOmitEmptyIntPtr",
+	"StructPtrHeadIntPtr",
+	"StructPtrHeadOmitEmptyIntPtr",
+	"StructHeadUintPtr",
+	"StructHeadOmitEmptyUintPtr",
+	"StructPtrHeadUintPtr",
+	"StructPtrHeadOmitEmptyUintPtr",
+	"StructHeadFloat32Ptr",
+	"StructHeadOmitEmptyFloat32Ptr",
+	"StructPtrHeadFloat32Ptr",
+	"StructPtrHeadOmitEmptyFloat32Ptr",
+	"StructHeadFloat64Ptr",
+	"StructHeadOmitEmptyFloat64Ptr",
+	"StructPtrHeadFloat64Ptr",
+	"StructPtrHeadOmitEmptyFloat64Ptr",
+	"StructHeadBoolPtr",
+	"StructHeadOmitEmptyBoolPtr",
+	"StructPtrHeadBoolPtr",
+	"StructPtrHeadOmitEmptyBoolPtr",
+	"StructHeadStringPtr",
+	"StructHeadOmitEmptyStringPtr",
+	"StructPtrHeadStringPtr",
+	"StructPtrHeadOmitEmptyStringPtr",
+	"StructHeadBytesPtr",
+	"StructHeadOmitEmptyBytesPtr",
+	"StructPtrHeadBytesPtr",
+	"StructPtrHeadOmitEmptyBytesPtr",
+	"StructHeadNumberPtr",
+	"StructHeadOmitEmptyNumberPtr",
+	"StructPtrHeadNumberPtr",
+	"StructPtrHeadOmitEmptyNumberPtr",
+	"StructHeadArrayPtr",
+	"StructHeadOmitEmptyArrayPtr",
+	"StructPtrHeadArrayPtr",
+	"StructPtrHeadOmitEmptyArrayPtr",
+	"StructHeadMapPtr",
+	"StructHeadOmitEmptyMapPtr",
+	"StructPtrHeadMapPtr",
+	"StructPtrHeadOmitEmptyMapPtr",
+	"StructHeadSlicePtr",
+	"StructHeadOmitEmptySlicePtr",
+	"StructPtrHeadSlicePtr",
+	"StructPtrHeadOmitEmptySlicePtr",
+	"StructHeadMarshalJSONPtr",
+	"StructHeadOmitEmptyMarshalJSONPtr",
+	"StructPtrHeadMarshalJSONPtr",
+	"StructPtrHeadOmitEmptyMarshalJSONPtr",
+	"StructHeadMarshalTextPtr",
+	"StructHeadOmitEmptyMarshalTextPtr",
+	"StructPtrHeadMarshalTextPtr",
+	"StructPtrHeadOmitEmptyMarshalTextPtr",
+	"StructHeadInterfacePtr",
+	"StructHeadOmitEmptyInterfacePtr",
+	"StructPtrHeadInterfacePtr",
+	"StructPtrHeadOmitEmptyInterfacePtr",
+	"StructHeadIntPtrString",
+	"StructHeadOmitEmptyIntPtrString",
+	"StructPtrHeadIntPtrString",
+	"StructPtrHeadOmitEmptyIntPtrString",
+	"StructHeadUintPtrString",
+	"StructHeadOmitEmptyUintPtrString",
+	"StructPtrHeadUintPtrString",
+	"StructPtrHeadOmitEmptyUintPtrString",
+	"StructHeadFloat32PtrString",
+	"StructHeadOmitEmptyFloat32PtrString",
+	"StructPtrHeadFloat32PtrString",
+	"StructPtrHeadOmitEmptyFloat32PtrString",
+	"StructHeadFloat64PtrString",
+	"StructHeadOmitEmptyFloat64PtrString",
+	"StructPtrHeadFloat64PtrString",
+	"StructPtrHeadOmitEmptyFloat64PtrString",
+	"StructHeadBoolPtrString",
+	"StructHeadOmitEmptyBoolPtrString",
+	"StructPtrHeadBoolPtrString",
+	"StructPtrHeadOmitEmptyBoolPtrString",
+	"StructHeadStringPtrString",
+	"StructHeadOmitEmptyStringPtrString",
+	"StructPtrHeadStringPtrString",
+	"StructPtrHeadOmitEmptyStringPtrString",
+	"StructHeadNumberPtrString",
+	"StructHeadOmitEmptyNumberPtrString",
+	"StructPtrHeadNumberPtrString",
+	"StructPtrHeadOmitEmptyNumberPtrString",
+	"StructHead",
+	"StructHeadOmitEmpty",
+	"StructPtrHead",
+	"StructPtrHeadOmitEmpty",
+	"StructFieldInt",
+	"StructFieldOmitEmptyInt",
+	"StructEndInt",
+	"StructEndOmitEmptyInt",
+	"StructFieldUint",
+	"StructFieldOmitEmptyUint",
+	"StructEndUint",
+	"StructEndOmitEmptyUint",
+	"StructFieldFloat32",
+	"StructFieldOmitEmptyFloat32",
+	"StructEndFloat32",
+	"StructEndOmitEmptyFloat32",
+	"StructFieldFloat64",
+	"StructFieldOmitEmptyFloat64",
+	"StructEndFloat64",
+	"StructEndOmitEmptyFloat64",
+	"StructFieldBool",
+	"StructFieldOmitEmptyBool",
+	"StructEndBool",
+	"StructEndOmitEmptyBool",
+	"StructFieldString",
+	"StructFieldOmitEmptyString",
+	"StructEndString",
+	"StructEndOmitEmptyString",
+	"StructFieldBytes",
+	"StructFieldOmitEmptyBytes",
+	"StructEndBytes",
+	"StructEndOmitEmptyBytes",
+	"StructFieldNumber",
+	"StructFieldOmitEmptyNumber",
+	"StructEndNumber",
+	"StructEndOmitEmptyNumber",
+	"StructFieldArray",
+	"StructFieldOmitEmptyArray",
+	"StructEndArray",
+	"StructEndOmitEmptyArray",
+	"StructFieldMap",
+	"StructFieldOmitEmptyMap",
+	"StructEndMap",
+	"StructEndOmitEmptyMap",
+	"StructFieldSlice",
+	"StructFieldOmitEmptySlice",
+	"StructEndSlice",
+	"StructEndOmitEmptySlice",
+	"StructFieldStruct",
+	"StructFieldOmitEmptyStruct",
+	"StructEndStruct",
+	"StructEndOmitEmptyStruct",
+	"StructFieldMarshalJSON",
+	"StructFieldOmitEmptyMarshalJSON",
+	"StructEndMarshalJSON",
+	"StructEndOmitEmptyMarshalJSON",
+	"StructFieldMarshalText",
+	"StructFieldOmitEmptyMarshalText",
+	"StructEndMarshalText",
+	"StructEndOmitEmptyMarshalText",
+	"StructFieldIntString",
+	"StructFieldOmitEmptyIntString",
+	"StructEndIntString",
+	"StructEndOmitEmptyIntString",
+	"StructFieldUintString",
+	"StructFieldOmitEmptyUintString",
+	"StructEndUintString",
+	"StructEndOmitEmptyUintString",
+	"StructFieldFloat32String",
+	"StructFieldOmitEmptyFloat32String",
+	"StructEndFloat32String",
+	"StructEndOmitEmptyFloat32String",
+	"StructFieldFloat64String",
+	"StructFieldOmitEmptyFloat64String",
+	"StructEndFloat64String",
+	"StructEndOmitEmptyFloat64String",
+	"StructFieldBoolString",
+	"StructFieldOmitEmptyBoolString",
+	"StructEndBoolString",
+	"StructEndOmitEmptyBoolString",
+	"StructFieldStringString",
+	"StructFieldOmitEmptyStringString",
+	"StructEndStringString",
+	"StructEndOmitEmptyStringString",
+	"StructFieldNumberString",
+	"StructFieldOmitEmptyNumberString",
+	"StructEndNumberString",
+	"StructEndOmitEmptyNumberString",
+	"StructFieldIntPtr",
+	"StructFieldOmitEmptyIntPtr",
+	"StructEndIntPtr",
+	"StructEndOmitEmptyIntPtr",
+	"StructFieldUintPtr",
+	"StructFieldOmitEmptyUintPtr",
+	"StructEndUintPtr",
+	"StructEndOmitEmptyUintPtr",
+	"StructFieldFloat32Ptr",
+	"StructFieldOmitEmptyFloat32Ptr",
+	"StructEndFloat32Ptr",
+	"StructEndOmitEmptyFloat32Ptr",
+	"StructFieldFloat64Ptr",
+	"StructFieldOmitEmptyFloat64Ptr",
+	"StructEndFloat64Ptr",
+	"StructEndOmitEmptyFloat64Ptr",
+	"StructFieldBoolPtr",
+	"StructFieldOmitEmptyBoolPtr",
+	"StructEndBoolPtr",
+	"StructEndOmitEmptyBoolPtr",
+	"StructFieldStringPtr",
+	"StructFieldOmitEmptyStringPtr",
+	"StructEndStringPtr",
+	"StructEndOmitEmptyStringPtr",
+	"StructFieldBytesPtr",
+	"StructFieldOmitEmptyBytesPtr",
+	"StructEndBytesPtr",
+	"StructEndOmitEmptyBytesPtr",
+	"StructFieldNumberPtr",
+	"StructFieldOmitEmptyNumberPtr",
+	"StructEndNumberPtr",
+	"StructEndOmitEmptyNumberPtr",
+	"StructFieldArrayPtr",
+	"StructFieldOmitEmptyArrayPtr",
+	"StructEndArrayPtr",
+	"StructEndOmitEmptyArrayPtr",
+	"StructFieldMapPtr",
+	"StructFieldOmitEmptyMapPtr",
+	"StructEndMapPtr",
+	"StructEndOmitEmptyMapPtr",
+	"StructFieldSlicePtr",
+	"StructFieldOmitEmptySlicePtr",
+	"StructEndSlicePtr",
+	"StructEndOmitEmptySlicePtr",
+	"StructFieldMarshalJSONPtr",
+	"StructFieldOmitEmptyMarshalJSONPtr",
+	"StructEndMarshalJSONPtr",
+	"StructEndOmitEmptyMarshalJSONPtr",
+	"StructFieldMarshalTextPtr",
+	"StructFieldOmitEmptyMarshalTextPtr",
+	"StructEndMarshalTextPtr",
+	"StructEndOmitEmptyMarshalTextPtr",
+	"StructFieldInterfacePtr",
+	"StructFieldOmitEmptyInterfacePtr",
+	"StructEndInterfacePtr",
+	"StructEndOmitEmptyInterfacePtr",
+	"StructFieldIntPtrString",
+	"StructFieldOmitEmptyIntPtrString",
+	"StructEndIntPtrString",
+	"StructEndOmitEmptyIntPtrString",
+	"StructFieldUintPtrString",
+	"StructFieldOmitEmptyUintPtrString",
+	"StructEndUintPtrString",
+	"StructEndOmitEmptyUintPtrString",
+	"StructFieldFloat32PtrString",
+	"StructFieldOmitEmptyFloat32PtrString",
+	"StructEndFloat32PtrString",
+	"StructEndOmitEmptyFloat32PtrString",
+	"StructFieldFloat64PtrString",
+	"StructFieldOmitEmptyFloat64PtrString",
+	"StructEndFloat64PtrString",
+	"StructEndOmitEmptyFloat64PtrString",
+	"StructFieldBoolPtrString",
+	"StructFieldOmitEmptyBoolPtrString",
+	"StructEndBoolPtrString",
+	"StructEndOmitEmptyBoolPtrString",
+	"StructFieldStringPtrString",
+	"StructFieldOmitEmptyStringPtrString",
+	"StructEndStringPtrString",
+	"StructEndOmitEmptyStringPtrString",
+	"StructFieldNumberPtrString",
+	"StructFieldOmitEmptyNumberPtrString",
+	"StructEndNumberPtrString",
+	"StructEndOmitEmptyNumberPtrString",
+	"StructField",
+	"StructFieldOmitEmpty",
+	"StructEnd",
+	"StructEndOmitEmpty",
+}
+
+type OpType uint16
+
+const (
+	OpEnd                                    OpType = 0
+	OpInterface                              OpType = 1
+	OpPtr                                    OpType = 2
+	OpSliceElem                              OpType = 3
+	OpSliceEnd                               OpType = 4
+	OpArrayElem                              OpType = 5
+	OpArrayEnd                               OpType = 6
+	OpMapKey                                 OpType = 7
+	OpMapValue                               OpType = 8
+	OpMapEnd                                 OpType = 9
+	OpRecursive                              OpType = 10
+	OpRecursivePtr                           OpType = 11
+	OpRecursiveEnd                           OpType = 12
+	OpInterfaceEnd                           OpType = 13
+	OpInt                                    OpType = 14
+	OpUint                                   OpType = 15
+	OpFloat32                                OpType = 16
+	OpFloat64                                OpType = 17
+	OpBool                                   OpType = 18
+	OpString                                 OpType = 19
+	OpBytes                                  OpType = 20
+	OpNumber                                 OpType = 21
+	OpArray                                  OpType = 22
+	OpMap                                    OpType = 23
+	OpSlice                                  OpType = 24
+	OpStruct                                 OpType = 25
+	OpMarshalJSON                            OpType = 26
+	OpMarshalText                            OpType = 27
+	OpIntString                              OpType = 28
+	OpUintString                             OpType = 29
+	OpFloat32String                          OpType = 30
+	OpFloat64String                          OpType = 31
+	OpBoolString                             OpType = 32
+	OpStringString                           OpType = 33
+	OpNumberString                           OpType = 34
+	OpIntPtr                                 OpType = 35
+	OpUintPtr                                OpType = 36
+	OpFloat32Ptr                             OpType = 37
+	OpFloat64Ptr                             OpType = 38
+	OpBoolPtr                                OpType = 39
+	OpStringPtr                              OpType = 40
+	OpBytesPtr                               OpType = 41
+	OpNumberPtr                              OpType = 42
+	OpArrayPtr                               OpType = 43
+	OpMapPtr                                 OpType = 44
+	OpSlicePtr                               OpType = 45
+	OpMarshalJSONPtr                         OpType = 46
+	OpMarshalTextPtr                         OpType = 47
+	OpInterfacePtr                           OpType = 48
+	OpIntPtrString                           OpType = 49
+	OpUintPtrString                          OpType = 50
+	OpFloat32PtrString                       OpType = 51
+	OpFloat64PtrString                       OpType = 52
+	OpBoolPtrString                          OpType = 53
+	OpStringPtrString                        OpType = 54
+	OpNumberPtrString                        OpType = 55
+	OpStructHeadInt                          OpType = 56
+	OpStructHeadOmitEmptyInt                 OpType = 57
+	OpStructPtrHeadInt                       OpType = 58
+	OpStructPtrHeadOmitEmptyInt              OpType = 59
+	OpStructHeadUint                         OpType = 60
+	OpStructHeadOmitEmptyUint                OpType = 61
+	OpStructPtrHeadUint                      OpType = 62
+	OpStructPtrHeadOmitEmptyUint             OpType = 63
+	OpStructHeadFloat32                      OpType = 64
+	OpStructHeadOmitEmptyFloat32             OpType = 65
+	OpStructPtrHeadFloat32                   OpType = 66
+	OpStructPtrHeadOmitEmptyFloat32          OpType = 67
+	OpStructHeadFloat64                      OpType = 68
+	OpStructHeadOmitEmptyFloat64             OpType = 69
+	OpStructPtrHeadFloat64                   OpType = 70
+	OpStructPtrHeadOmitEmptyFloat64          OpType = 71
+	OpStructHeadBool                         OpType = 72
+	OpStructHeadOmitEmptyBool                OpType = 73
+	OpStructPtrHeadBool                      OpType = 74
+	OpStructPtrHeadOmitEmptyBool             OpType = 75
+	OpStructHeadString                       OpType = 76
+	OpStructHeadOmitEmptyString              OpType = 77
+	OpStructPtrHeadString                    OpType = 78
+	OpStructPtrHeadOmitEmptyString           OpType = 79
+	OpStructHeadBytes                        OpType = 80
+	OpStructHeadOmitEmptyBytes               OpType = 81
+	OpStructPtrHeadBytes                     OpType = 82
+	OpStructPtrHeadOmitEmptyBytes            OpType = 83
+	OpStructHeadNumber                       OpType = 84
+	OpStructHeadOmitEmptyNumber              OpType = 85
+	OpStructPtrHeadNumber                    OpType = 86
+	OpStructPtrHeadOmitEmptyNumber           OpType = 87
+	OpStructHeadArray                        OpType = 88
+	OpStructHeadOmitEmptyArray               OpType = 89
+	OpStructPtrHeadArray                     OpType = 90
+	OpStructPtrHeadOmitEmptyArray            OpType = 91
+	OpStructHeadMap                          OpType = 92
+	OpStructHeadOmitEmptyMap                 OpType = 93
+	OpStructPtrHeadMap                       OpType = 94
+	OpStructPtrHeadOmitEmptyMap              OpType = 95
+	OpStructHeadSlice                        OpType = 96
+	OpStructHeadOmitEmptySlice               OpType = 97
+	OpStructPtrHeadSlice                     OpType = 98
+	OpStructPtrHeadOmitEmptySlice            OpType = 99
+	OpStructHeadStruct                       OpType = 100
+	OpStructHeadOmitEmptyStruct              OpType = 101
+	OpStructPtrHeadStruct                    OpType = 102
+	OpStructPtrHeadOmitEmptyStruct           OpType = 103
+	OpStructHeadMarshalJSON                  OpType = 104
+	OpStructHeadOmitEmptyMarshalJSON         OpType = 105
+	OpStructPtrHeadMarshalJSON               OpType = 106
+	OpStructPtrHeadOmitEmptyMarshalJSON      OpType = 107
+	OpStructHeadMarshalText                  OpType = 108
+	OpStructHeadOmitEmptyMarshalText         OpType = 109
+	OpStructPtrHeadMarshalText               OpType = 110
+	OpStructPtrHeadOmitEmptyMarshalText      OpType = 111
+	OpStructHeadIntString                    OpType = 112
+	OpStructHeadOmitEmptyIntString           OpType = 113
+	OpStructPtrHeadIntString                 OpType = 114
+	OpStructPtrHeadOmitEmptyIntString        OpType = 115
+	OpStructHeadUintString                   OpType = 116
+	OpStructHeadOmitEmptyUintString          OpType = 117
+	OpStructPtrHeadUintString                OpType = 118
+	OpStructPtrHeadOmitEmptyUintString       OpType = 119
+	OpStructHeadFloat32String                OpType = 120
+	OpStructHeadOmitEmptyFloat32String       OpType = 121
+	OpStructPtrHeadFloat32String             OpType = 122
+	OpStructPtrHeadOmitEmptyFloat32String    OpType = 123
+	OpStructHeadFloat64String                OpType = 124
+	OpStructHeadOmitEmptyFloat64String       OpType = 125
+	OpStructPtrHeadFloat64String             OpType = 126
+	OpStructPtrHeadOmitEmptyFloat64String    OpType = 127
+	OpStructHeadBoolString                   OpType = 128
+	OpStructHeadOmitEmptyBoolString          OpType = 129
+	OpStructPtrHeadBoolString                OpType = 130
+	OpStructPtrHeadOmitEmptyBoolString       OpType = 131
+	OpStructHeadStringString                 OpType = 132
+	OpStructHeadOmitEmptyStringString        OpType = 133
+	OpStructPtrHeadStringString              OpType = 134
+	OpStructPtrHeadOmitEmptyStringString     OpType = 135
+	OpStructHeadNumberString                 OpType = 136
+	OpStructHeadOmitEmptyNumberString        OpType = 137
+	OpStructPtrHeadNumberString              OpType = 138
+	OpStructPtrHeadOmitEmptyNumberString     OpType = 139
+	OpStructHeadIntPtr                       OpType = 140
+	OpStructHeadOmitEmptyIntPtr              OpType = 141
+	OpStructPtrHeadIntPtr                    OpType = 142
+	OpStructPtrHeadOmitEmptyIntPtr           OpType = 143
+	OpStructHeadUintPtr                      OpType = 144
+	OpStructHeadOmitEmptyUintPtr             OpType = 145
+	OpStructPtrHeadUintPtr                   OpType = 146
+	OpStructPtrHeadOmitEmptyUintPtr          OpType = 147
+	OpStructHeadFloat32Ptr                   OpType = 148
+	OpStructHeadOmitEmptyFloat32Ptr          OpType = 149
+	OpStructPtrHeadFloat32Ptr                OpType = 150
+	OpStructPtrHeadOmitEmptyFloat32Ptr       OpType = 151
+	OpStructHeadFloat64Ptr                   OpType = 152
+	OpStructHeadOmitEmptyFloat64Ptr          OpType = 153
+	OpStructPtrHeadFloat64Ptr                OpType = 154
+	OpStructPtrHeadOmitEmptyFloat64Ptr       OpType = 155
+	OpStructHeadBoolPtr                      OpType = 156
+	OpStructHeadOmitEmptyBoolPtr             OpType = 157
+	OpStructPtrHeadBoolPtr                   OpType = 158
+	OpStructPtrHeadOmitEmptyBoolPtr          OpType = 159
+	OpStructHeadStringPtr                    OpType = 160
+	OpStructHeadOmitEmptyStringPtr           OpType = 161
+	OpStructPtrHeadStringPtr                 OpType = 162
+	OpStructPtrHeadOmitEmptyStringPtr        OpType = 163
+	OpStructHeadBytesPtr                     OpType = 164
+	OpStructHeadOmitEmptyBytesPtr            OpType = 165
+	OpStructPtrHeadBytesPtr                  OpType = 166
+	OpStructPtrHeadOmitEmptyBytesPtr         OpType = 167
+	OpStructHeadNumberPtr                    OpType = 168
+	OpStructHeadOmitEmptyNumberPtr           OpType = 169
+	OpStructPtrHeadNumberPtr                 OpType = 170
+	OpStructPtrHeadOmitEmptyNumberPtr        OpType = 171
+	OpStructHeadArrayPtr                     OpType = 172
+	OpStructHeadOmitEmptyArrayPtr            OpType = 173
+	OpStructPtrHeadArrayPtr                  OpType = 174
+	OpStructPtrHeadOmitEmptyArrayPtr         OpType = 175
+	OpStructHeadMapPtr                       OpType = 176
+	OpStructHeadOmitEmptyMapPtr              OpType = 177
+	OpStructPtrHeadMapPtr                    OpType = 178
+	OpStructPtrHeadOmitEmptyMapPtr           OpType = 179
+	OpStructHeadSlicePtr                     OpType = 180
+	OpStructHeadOmitEmptySlicePtr            OpType = 181
+	OpStructPtrHeadSlicePtr                  OpType = 182
+	OpStructPtrHeadOmitEmptySlicePtr         OpType = 183
+	OpStructHeadMarshalJSONPtr               OpType = 184
+	OpStructHeadOmitEmptyMarshalJSONPtr      OpType = 185
+	OpStructPtrHeadMarshalJSONPtr            OpType = 186
+	OpStructPtrHeadOmitEmptyMarshalJSONPtr   OpType = 187
+	OpStructHeadMarshalTextPtr               OpType = 188
+	OpStructHeadOmitEmptyMarshalTextPtr      OpType = 189
+	OpStructPtrHeadMarshalTextPtr            OpType = 190
+	OpStructPtrHeadOmitEmptyMarshalTextPtr   OpType = 191
+	OpStructHeadInterfacePtr                 OpType = 192
+	OpStructHeadOmitEmptyInterfacePtr        OpType = 193
+	OpStructPtrHeadInterfacePtr              OpType = 194
+	OpStructPtrHeadOmitEmptyInterfacePtr     OpType = 195
+	OpStructHeadIntPtrString                 OpType = 196
+	OpStructHeadOmitEmptyIntPtrString        OpType = 197
+	OpStructPtrHeadIntPtrString              OpType = 198
+	OpStructPtrHeadOmitEmptyIntPtrString     OpType = 199
+	OpStructHeadUintPtrString                OpType = 200
+	OpStructHeadOmitEmptyUintPtrString       OpType = 201
+	OpStructPtrHeadUintPtrString             OpType = 202
+	OpStructPtrHeadOmitEmptyUintPtrString    OpType = 203
+	OpStructHeadFloat32PtrString             OpType = 204
+	OpStructHeadOmitEmptyFloat32PtrString    OpType = 205
+	OpStructPtrHeadFloat32PtrString          OpType = 206
+	OpStructPtrHeadOmitEmptyFloat32PtrString OpType = 207
+	OpStructHeadFloat64PtrString             OpType = 208
+	OpStructHeadOmitEmptyFloat64PtrString    OpType = 209
+	OpStructPtrHeadFloat64PtrString          OpType = 210
+	OpStructPtrHeadOmitEmptyFloat64PtrString OpType = 211
+	OpStructHeadBoolPtrString                OpType = 212
+	OpStructHeadOmitEmptyBoolPtrString       OpType = 213
+	OpStructPtrHeadBoolPtrString             OpType = 214
+	OpStructPtrHeadOmitEmptyBoolPtrString    OpType = 215
+	OpStructHeadStringPtrString              OpType = 216
+	OpStructHeadOmitEmptyStringPtrString     OpType = 217
+	OpStructPtrHeadStringPtrString           OpType = 218
+	OpStructPtrHeadOmitEmptyStringPtrString  OpType = 219
+	OpStructHeadNumberPtrString              OpType = 220
+	OpStructHeadOmitEmptyNumberPtrString     OpType = 221
+	OpStructPtrHeadNumberPtrString           OpType = 222
+	OpStructPtrHeadOmitEmptyNumberPtrString  OpType = 223
+	OpStructHead                             OpType = 224
+	OpStructHeadOmitEmpty                    OpType = 225
+	OpStructPtrHead                          OpType = 226
+	OpStructPtrHeadOmitEmpty                 OpType = 227
+	OpStructFieldInt                         OpType = 228
+	OpStructFieldOmitEmptyInt                OpType = 229
+	OpStructEndInt                           OpType = 230
+	OpStructEndOmitEmptyInt                  OpType = 231
+	OpStructFieldUint                        OpType = 232
+	OpStructFieldOmitEmptyUint               OpType = 233
+	OpStructEndUint                          OpType = 234
+	OpStructEndOmitEmptyUint                 OpType = 235
+	OpStructFieldFloat32                     OpType = 236
+	OpStructFieldOmitEmptyFloat32            OpType = 237
+	OpStructEndFloat32                       OpType = 238
+	OpStructEndOmitEmptyFloat32              OpType = 239
+	OpStructFieldFloat64                     OpType = 240
+	OpStructFieldOmitEmptyFloat64            OpType = 241
+	OpStructEndFloat64                       OpType = 242
+	OpStructEndOmitEmptyFloat64              OpType = 243
+	OpStructFieldBool                        OpType = 244
+	OpStructFieldOmitEmptyBool               OpType = 245
+	OpStructEndBool                          OpType = 246
+	OpStructEndOmitEmptyBool                 OpType = 247
+	OpStructFieldString                      OpType = 248
+	OpStructFieldOmitEmptyString             OpType = 249
+	OpStructEndString                        OpType = 250
+	OpStructEndOmitEmptyString               OpType = 251
+	OpStructFieldBytes                       OpType = 252
+	OpStructFieldOmitEmptyBytes              OpType = 253
+	OpStructEndBytes                         OpType = 254
+	OpStructEndOmitEmptyBytes                OpType = 255
+	OpStructFieldNumber                      OpType = 256
+	OpStructFieldOmitEmptyNumber             OpType = 257
+	OpStructEndNumber                        OpType = 258
+	OpStructEndOmitEmptyNumber               OpType = 259
+	OpStructFieldArray                       OpType = 260
+	OpStructFieldOmitEmptyArray              OpType = 261
+	OpStructEndArray                         OpType = 262
+	OpStructEndOmitEmptyArray                OpType = 263
+	OpStructFieldMap                         OpType = 264
+	OpStructFieldOmitEmptyMap                OpType = 265
+	OpStructEndMap                           OpType = 266
+	OpStructEndOmitEmptyMap                  OpType = 267
+	OpStructFieldSlice                       OpType = 268
+	OpStructFieldOmitEmptySlice              OpType = 269
+	OpStructEndSlice                         OpType = 270
+	OpStructEndOmitEmptySlice                OpType = 271
+	OpStructFieldStruct                      OpType = 272
+	OpStructFieldOmitEmptyStruct             OpType = 273
+	OpStructEndStruct                        OpType = 274
+	OpStructEndOmitEmptyStruct               OpType = 275
+	OpStructFieldMarshalJSON                 OpType = 276
+	OpStructFieldOmitEmptyMarshalJSON        OpType = 277
+	OpStructEndMarshalJSON                   OpType = 278
+	OpStructEndOmitEmptyMarshalJSON          OpType = 279
+	OpStructFieldMarshalText                 OpType = 280
+	OpStructFieldOmitEmptyMarshalText        OpType = 281
+	OpStructEndMarshalText                   OpType = 282
+	OpStructEndOmitEmptyMarshalText          OpType = 283
+	OpStructFieldIntString                   OpType = 284
+	OpStructFieldOmitEmptyIntString          OpType = 285
+	OpStructEndIntString                     OpType = 286
+	OpStructEndOmitEmptyIntString            OpType = 287
+	OpStructFieldUintString                  OpType = 288
+	OpStructFieldOmitEmptyUintString         OpType = 289
+	OpStructEndUintString                    OpType = 290
+	OpStructEndOmitEmptyUintString           OpType = 291
+	OpStructFieldFloat32String               OpType = 292
+	OpStructFieldOmitEmptyFloat32String      OpType = 293
+	OpStructEndFloat32String                 OpType = 294
+	OpStructEndOmitEmptyFloat32String        OpType = 295
+	OpStructFieldFloat64String               OpType = 296
+	OpStructFieldOmitEmptyFloat64String      OpType = 297
+	OpStructEndFloat64String                 OpType = 298
+	OpStructEndOmitEmptyFloat64String        OpType = 299
+	OpStructFieldBoolString                  OpType = 300
+	OpStructFieldOmitEmptyBoolString         OpType = 301
+	OpStructEndBoolString                    OpType = 302
+	OpStructEndOmitEmptyBoolString           OpType = 303
+	OpStructFieldStringString                OpType = 304
+	OpStructFieldOmitEmptyStringString       OpType = 305
+	OpStructEndStringString                  OpType = 306
+	OpStructEndOmitEmptyStringString         OpType = 307
+	OpStructFieldNumberString                OpType = 308
+	OpStructFieldOmitEmptyNumberString       OpType = 309
+	OpStructEndNumberString                  OpType = 310
+	OpStructEndOmitEmptyNumberString         OpType = 311
+	OpStructFieldIntPtr                      OpType = 312
+	OpStructFieldOmitEmptyIntPtr             OpType = 313
+	OpStructEndIntPtr                        OpType = 314
+	OpStructEndOmitEmptyIntPtr               OpType = 315
+	OpStructFieldUintPtr                     OpType = 316
+	OpStructFieldOmitEmptyUintPtr            OpType = 317
+	OpStructEndUintPtr                       OpType = 318
+	OpStructEndOmitEmptyUintPtr              OpType = 319
+	OpStructFieldFloat32Ptr                  OpType = 320
+	OpStructFieldOmitEmptyFloat32Ptr         OpType = 321
+	OpStructEndFloat32Ptr                    OpType = 322
+	OpStructEndOmitEmptyFloat32Ptr           OpType = 323
+	OpStructFieldFloat64Ptr                  OpType = 324
+	OpStructFieldOmitEmptyFloat64Ptr         OpType = 325
+	OpStructEndFloat64Ptr                    OpType = 326
+	OpStructEndOmitEmptyFloat64Ptr           OpType = 327
+	OpStructFieldBoolPtr                     OpType = 328
+	OpStructFieldOmitEmptyBoolPtr            OpType = 329
+	OpStructEndBoolPtr                       OpType = 330
+	OpStructEndOmitEmptyBoolPtr              OpType = 331
+	OpStructFieldStringPtr                   OpType = 332
+	OpStructFieldOmitEmptyStringPtr          OpType = 333
+	OpStructEndStringPtr                     OpType = 334
+	OpStructEndOmitEmptyStringPtr            OpType = 335
+	OpStructFieldBytesPtr                    OpType = 336
+	OpStructFieldOmitEmptyBytesPtr           OpType = 337
+	OpStructEndBytesPtr                      OpType = 338
+	OpStructEndOmitEmptyBytesPtr             OpType = 339
+	OpStructFieldNumberPtr                   OpType = 340
+	OpStructFieldOmitEmptyNumberPtr          OpType = 341
+	OpStructEndNumberPtr                     OpType = 342
+	OpStructEndOmitEmptyNumberPtr            OpType = 343
+	OpStructFieldArrayPtr                    OpType = 344
+	OpStructFieldOmitEmptyArrayPtr           OpType = 345
+	OpStructEndArrayPtr                      OpType = 346
+	OpStructEndOmitEmptyArrayPtr             OpType = 347
+	OpStructFieldMapPtr                      OpType = 348
+	OpStructFieldOmitEmptyMapPtr             OpType = 349
+	OpStructEndMapPtr                        OpType = 350
+	OpStructEndOmitEmptyMapPtr               OpType = 351
+	OpStructFieldSlicePtr                    OpType = 352
+	OpStructFieldOmitEmptySlicePtr           OpType = 353
+	OpStructEndSlicePtr                      OpType = 354
+	OpStructEndOmitEmptySlicePtr             OpType = 355
+	OpStructFieldMarshalJSONPtr              OpType = 356
+	OpStructFieldOmitEmptyMarshalJSONPtr     OpType = 357
+	OpStructEndMarshalJSONPtr                OpType = 358
+	OpStructEndOmitEmptyMarshalJSONPtr       OpType = 359
+	OpStructFieldMarshalTextPtr              OpType = 360
+	OpStructFieldOmitEmptyMarshalTextPtr     OpType = 361
+	OpStructEndMarshalTextPtr                OpType = 362
+	OpStructEndOmitEmptyMarshalTextPtr       OpType = 363
+	OpStructFieldInterfacePtr                OpType = 364
+	OpStructFieldOmitEmptyInterfacePtr       OpType = 365
+	OpStructEndInterfacePtr                  OpType = 366
+	OpStructEndOmitEmptyInterfacePtr         OpType = 367
+	OpStructFieldIntPtrString                OpType = 368
+	OpStructFieldOmitEmptyIntPtrString       OpType = 369
+	OpStructEndIntPtrString                  OpType = 370
+	OpStructEndOmitEmptyIntPtrString         OpType = 371
+	OpStructFieldUintPtrString               OpType = 372
+	OpStructFieldOmitEmptyUintPtrString      OpType = 373
+	OpStructEndUintPtrString                 OpType = 374
+	OpStructEndOmitEmptyUintPtrString        OpType = 375
+	OpStructFieldFloat32PtrString            OpType = 376
+	OpStructFieldOmitEmptyFloat32PtrString   OpType = 377
+	OpStructEndFloat32PtrString              OpType = 378
+	OpStructEndOmitEmptyFloat32PtrString     OpType = 379
+	OpStructFieldFloat64PtrString            OpType = 380
+	OpStructFieldOmitEmptyFloat64PtrString   OpType = 381
+	OpStructEndFloat64PtrString              OpType = 382
+	OpStructEndOmitEmptyFloat64PtrString     OpType = 383
+	OpStructFieldBoolPtrString               OpType = 384
+	OpStructFieldOmitEmptyBoolPtrString      OpType = 385
+	OpStructEndBoolPtrString                 OpType = 386
+	OpStructEndOmitEmptyBoolPtrString        OpType = 387
+	OpStructFieldStringPtrString             OpType = 388
+	OpStructFieldOmitEmptyStringPtrString    OpType = 389
+	OpStructEndStringPtrString               OpType = 390
+	OpStructEndOmitEmptyStringPtrString      OpType = 391
+	OpStructFieldNumberPtrString             OpType = 392
+	OpStructFieldOmitEmptyNumberPtrString    OpType = 393
+	OpStructEndNumberPtrString               OpType = 394
+	OpStructEndOmitEmptyNumberPtrString      OpType = 395
+	OpStructField                            OpType = 396
+	OpStructFieldOmitEmpty                   OpType = 397
+	OpStructEnd                              OpType = 398
+	OpStructEndOmitEmpty                     OpType = 399
+)
+
+func (t OpType) String() string {
+	if int(t) >= 400 {
+		return ""
+	}
+	return opTypeStrings[int(t)]
+}
+
+func (t OpType) CodeType() CodeType {
+	if strings.Contains(t.String(), "Struct") {
+		if strings.Contains(t.String(), "End") {
+			return CodeStructEnd
+		}
+		return CodeStructField
+	}
+	switch t {
+	case OpArray, OpArrayPtr:
+		return CodeArrayHead
+	case OpArrayElem:
+		return CodeArrayElem
+	case OpSlice, OpSlicePtr:
+		return CodeSliceHead
+	case OpSliceElem:
+		return CodeSliceElem
+	case OpMap, OpMapPtr:
+		return CodeMapHead
+	case OpMapKey:
+		return CodeMapKey
+	case OpMapValue:
+		return CodeMapValue
+	case OpMapEnd:
+		return CodeMapEnd
+	}
+
+	return CodeOp
+}
+
+func (t OpType) HeadToPtrHead() OpType {
+	if strings.Index(t.String(), "PtrHead") > 0 {
+		return t
+	}
+
+	idx := strings.Index(t.String(), "Head")
+	if idx == -1 {
+		return t
+	}
+	suffix := "PtrHead" + t.String()[idx+len("Head"):]
+
+	const toPtrOffset = 2
+	if strings.Contains(OpType(int(t)+toPtrOffset).String(), suffix) {
+		return OpType(int(t) + toPtrOffset)
+	}
+	return t
+}
+
+func (t OpType) HeadToOmitEmptyHead() OpType {
+	const toOmitEmptyOffset = 1
+	if strings.Contains(OpType(int(t)+toOmitEmptyOffset).String(), "OmitEmpty") {
+		return OpType(int(t) + toOmitEmptyOffset)
+	}
+
+	return t
+}
+
+func (t OpType) PtrHeadToHead() OpType {
+	idx := strings.Index(t.String(), "PtrHead")
+	if idx == -1 {
+		return t
+	}
+	suffix := t.String()[idx+len("Ptr"):]
+
+	const toPtrOffset = 2
+	if strings.Contains(OpType(int(t)-toPtrOffset).String(), suffix) {
+		return OpType(int(t) - toPtrOffset)
+	}
+	return t
+}
+
+func (t OpType) FieldToEnd() OpType {
+	idx := strings.Index(t.String(), "Field")
+	if idx == -1 {
+		return t
+	}
+	suffix := t.String()[idx+len("Field"):]
+	if suffix == "" || suffix == "OmitEmpty" {
+		return t
+	}
+	const toEndOffset = 2
+	if strings.Contains(OpType(int(t)+toEndOffset).String(), "End"+suffix) {
+		return OpType(int(t) + toEndOffset)
+	}
+	return t
+}
+
+func (t OpType) FieldToOmitEmptyField() OpType {
+	const toOmitEmptyOffset = 1
+	if strings.Contains(OpType(int(t)+toOmitEmptyOffset).String(), "OmitEmpty") {
+		return OpType(int(t) + toOmitEmptyOffset)
+	}
+	return t
+}

internal/encoder/query.go

@@ -0,0 +1,135 @@
+package encoder
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+)
+
+var (
+	Marshal   func(interface{}) ([]byte, error)
+	Unmarshal func([]byte, interface{}) error
+)
+
+type FieldQuery struct {
+	Name   string
+	Fields []*FieldQuery
+	hash   string
+}
+
+func (q *FieldQuery) Hash() string {
+	if q.hash != "" {
+		return q.hash
+	}
+	b, _ := Marshal(q)
+	q.hash = string(b)
+	return q.hash
+}
+
+func (q *FieldQuery) MarshalJSON() ([]byte, error) {
+	if q.Name != "" {
+		if len(q.Fields) > 0 {
+			return Marshal(map[string][]*FieldQuery{q.Name: q.Fields})
+		}
+		return Marshal(q.Name)
+	}
+	return Marshal(q.Fields)
+}
+
+func (q *FieldQuery) QueryString() (FieldQueryString, error) {
+	b, err := Marshal(q)
+	if err != nil {
+		return "", err
+	}
+	return FieldQueryString(b), nil
+}
+
+type FieldQueryString string
+
+func (s FieldQueryString) Build() (*FieldQuery, error) {
+	var query interface{}
+	if err := Unmarshal([]byte(s), &query); err != nil {
+		return nil, err
+	}
+	return s.build(reflect.ValueOf(query))
+}
+
+func (s FieldQueryString) build(v reflect.Value) (*FieldQuery, error) {
+	switch v.Type().Kind() {
+	case reflect.String:
+		return s.buildString(v)
+	case reflect.Map:
+		return s.buildMap(v)
+	case reflect.Slice:
+		return s.buildSlice(v)
+	case reflect.Interface:
+		return s.build(reflect.ValueOf(v.Interface()))
+	}
+	return nil, fmt.Errorf("failed to build field query")
+}
+
+func (s FieldQueryString) buildString(v reflect.Value) (*FieldQuery, error) {
+	b := []byte(v.String())
+	switch b[0] {
+	case '[', '{':
+		var query interface{}
+		if err := Unmarshal(b, &query); err != nil {
+			return nil, err
+		}
+		if str, ok := query.(string); ok {
+			return &FieldQuery{Name: str}, nil
+		}
+		return s.build(reflect.ValueOf(query))
+	}
+	return &FieldQuery{Name: string(b)}, nil
+}
+
+func (s FieldQueryString) buildSlice(v reflect.Value) (*FieldQuery, error) {
+	fields := make([]*FieldQuery, 0, v.Len())
+	for i := 0; i < v.Len(); i++ {
+		def, err := s.build(v.Index(i))
+		if err != nil {
+			return nil, err
+		}
+		fields = append(fields, def)
+	}
+	return &FieldQuery{Fields: fields}, nil
+}
+
+func (s FieldQueryString) buildMap(v reflect.Value) (*FieldQuery, error) {
+	keys := v.MapKeys()
+	if len(keys) != 1 {
+		return nil, fmt.Errorf("failed to build field query object")
+	}
+	key := keys[0]
+	if key.Type().Kind() != reflect.String {
+		return nil, fmt.Errorf("failed to build field query. invalid object key type")
+	}
+	name := key.String()
+	def, err := s.build(v.MapIndex(key))
+	if err != nil {
+		return nil, err
+	}
+	return &FieldQuery{
+		Name:   name,
+		Fields: def.Fields,
+	}, nil
+}
+
+type queryKey struct{}
+
+func FieldQueryFromContext(ctx context.Context) *FieldQuery {
+	query := ctx.Value(queryKey{})
+	if query == nil {
+		return nil
+	}
+	q, ok := query.(*FieldQuery)
+	if !ok {
+		return nil
+	}
+	return q
+}
+
+func SetFieldQueryToContext(ctx context.Context, query *FieldQuery) context.Context {
+	return context.WithValue(ctx, queryKey{}, query)
+}

internal/encoder/string.go

@@ -0,0 +1,483 @@
+// This files's string processing codes are inspired by https://github.com/segmentio/encoding.
+// The license notation is as follows.
+//
+// # MIT License
+//
+// Copyright (c) 2019 Segment.io, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+package encoder
+
+import (
+	"math/bits"
+	"reflect"
+	"unsafe"
+)
+
+const (
+	lsb = 0x0101010101010101
+	msb = 0x8080808080808080
+)
+
+var hex = "0123456789abcdef"
+
+//nolint:govet
+func stringToUint64Slice(s string) []uint64 {
+	return *(*[]uint64)(unsafe.Pointer(&reflect.SliceHeader{
+		Data: ((*reflect.StringHeader)(unsafe.Pointer(&s))).Data,
+		Len:  len(s) / 8,
+		Cap:  len(s) / 8,
+	}))
+}
+
+func AppendString(ctx *RuntimeContext, buf []byte, s string) []byte {
+	if ctx.Option.Flag&HTMLEscapeOption != 0 {
+		if ctx.Option.Flag&NormalizeUTF8Option != 0 {
+			return appendNormalizedHTMLString(buf, s)
+		}
+		return appendHTMLString(buf, s)
+	}
+	if ctx.Option.Flag&NormalizeUTF8Option != 0 {
+		return appendNormalizedString(buf, s)
+	}
+	return appendString(buf, s)
+}
+
+func appendNormalizedHTMLString(buf []byte, s string) []byte {
+	valLen := len(s)
+	if valLen == 0 {
+		return append(buf, `""`...)
+	}
+	buf = append(buf, '"')
+	var (
+		i, j int
+	)
+	if valLen >= 8 {
+		chunks := stringToUint64Slice(s)
+		for _, n := range chunks {
+			// combine masks before checking for the MSB of each byte. We include
+			// `n` in the mask to check whether any of the *input* byte MSBs were
+			// set (i.e. the byte was outside the ASCII range).
+			mask := n | (n - (lsb * 0x20)) |
+				((n ^ (lsb * '"')) - lsb) |
+				((n ^ (lsb * '\\')) - lsb) |
+				((n ^ (lsb * '<')) - lsb) |
+				((n ^ (lsb * '>')) - lsb) |
+				((n ^ (lsb * '&')) - lsb)
+			if (mask & msb) != 0 {
+				j = bits.TrailingZeros64(mask&msb) / 8
+				goto ESCAPE_END
+			}
+		}
+		for i := len(chunks) * 8; i < valLen; i++ {
+			if needEscapeHTMLNormalizeUTF8[s[i]] {
+				j = i
+				goto ESCAPE_END
+			}
+		}
+		// no found any escape characters.
+		return append(append(buf, s...), '"')
+	}
+ESCAPE_END:
+	for j < valLen {
+		c := s[j]
+
+		if !needEscapeHTMLNormalizeUTF8[c] {
+			// fast path: most of the time, printable ascii characters are used
+			j++
+			continue
+		}
+
+		switch c {
+		case '\\', '"':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', c)
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\n':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'n')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\r':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'r')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\t':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 't')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '<', '>', '&':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+
+		case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
+			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+		}
+		state, size := decodeRuneInString(s[j:])
+		switch state {
+		case runeErrorState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\ufffd`...)
+			i = j + 1
+			j = j + 1
+			continue
+			// U+2028 is LINE SEPARATOR.
+			// U+2029 is PARAGRAPH SEPARATOR.
+			// They are both technically valid characters in JSON strings,
+			// but don't work in JSONP, which has to be evaluated as JavaScript,
+			// and can lead to security holes there. It is valid JSON to
+			// escape them, so we do so unconditionally.
+			// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
+		case lineSepState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u2028`...)
+			i = j + 3
+			j = j + 3
+			continue
+		case paragraphSepState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u2029`...)
+			i = j + 3
+			j = j + 3
+			continue
+		}
+		j += size
+	}
+
+	return append(append(buf, s[i:]...), '"')
+}
+
+func appendHTMLString(buf []byte, s string) []byte {
+	valLen := len(s)
+	if valLen == 0 {
+		return append(buf, `""`...)
+	}
+	buf = append(buf, '"')
+	var (
+		i, j int
+	)
+	if valLen >= 8 {
+		chunks := stringToUint64Slice(s)
+		for _, n := range chunks {
+			// combine masks before checking for the MSB of each byte. We include
+			// `n` in the mask to check whether any of the *input* byte MSBs were
+			// set (i.e. the byte was outside the ASCII range).
+			mask := n | (n - (lsb * 0x20)) |
+				((n ^ (lsb * '"')) - lsb) |
+				((n ^ (lsb * '\\')) - lsb) |
+				((n ^ (lsb * '<')) - lsb) |
+				((n ^ (lsb * '>')) - lsb) |
+				((n ^ (lsb * '&')) - lsb)
+			if (mask & msb) != 0 {
+				j = bits.TrailingZeros64(mask&msb) / 8
+				goto ESCAPE_END
+			}
+		}
+		for i := len(chunks) * 8; i < valLen; i++ {
+			if needEscapeHTML[s[i]] {
+				j = i
+				goto ESCAPE_END
+			}
+		}
+		// no found any escape characters.
+		return append(append(buf, s...), '"')
+	}
+ESCAPE_END:
+	for j < valLen {
+		c := s[j]
+
+		if !needEscapeHTML[c] {
+			// fast path: most of the time, printable ascii characters are used
+			j++
+			continue
+		}
+
+		switch c {
+		case '\\', '"':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', c)
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\n':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'n')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\r':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'r')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\t':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 't')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '<', '>', '&':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+
+		case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
+			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+		}
+		j++
+	}
+
+	return append(append(buf, s[i:]...), '"')
+}
+
+func appendNormalizedString(buf []byte, s string) []byte {
+	valLen := len(s)
+	if valLen == 0 {
+		return append(buf, `""`...)
+	}
+	buf = append(buf, '"')
+	var (
+		i, j int
+	)
+	if valLen >= 8 {
+		chunks := stringToUint64Slice(s)
+		for _, n := range chunks {
+			// combine masks before checking for the MSB of each byte. We include
+			// `n` in the mask to check whether any of the *input* byte MSBs were
+			// set (i.e. the byte was outside the ASCII range).
+			mask := n | (n - (lsb * 0x20)) |
+				((n ^ (lsb * '"')) - lsb) |
+				((n ^ (lsb * '\\')) - lsb)
+			if (mask & msb) != 0 {
+				j = bits.TrailingZeros64(mask&msb) / 8
+				goto ESCAPE_END
+			}
+		}
+		valLen := len(s)
+		for i := len(chunks) * 8; i < valLen; i++ {
+			if needEscapeNormalizeUTF8[s[i]] {
+				j = i
+				goto ESCAPE_END
+			}
+		}
+		return append(append(buf, s...), '"')
+	}
+ESCAPE_END:
+	for j < valLen {
+		c := s[j]
+
+		if !needEscapeNormalizeUTF8[c] {
+			// fast path: most of the time, printable ascii characters are used
+			j++
+			continue
+		}
+
+		switch c {
+		case '\\', '"':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', c)
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\n':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'n')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\r':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'r')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\t':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 't')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
+			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+		}
+
+		state, size := decodeRuneInString(s[j:])
+		switch state {
+		case runeErrorState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\ufffd`...)
+			i = j + 1
+			j = j + 1
+			continue
+			// U+2028 is LINE SEPARATOR.
+			// U+2029 is PARAGRAPH SEPARATOR.
+			// They are both technically valid characters in JSON strings,
+			// but don't work in JSONP, which has to be evaluated as JavaScript,
+			// and can lead to security holes there. It is valid JSON to
+			// escape them, so we do so unconditionally.
+			// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
+		case lineSepState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u2028`...)
+			i = j + 3
+			j = j + 3
+			continue
+		case paragraphSepState:
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u2029`...)
+			i = j + 3
+			j = j + 3
+			continue
+		}
+		j += size
+	}
+
+	return append(append(buf, s[i:]...), '"')
+}
+
+func appendString(buf []byte, s string) []byte {
+	valLen := len(s)
+	if valLen == 0 {
+		return append(buf, `""`...)
+	}
+	buf = append(buf, '"')
+	var (
+		i, j int
+	)
+	if valLen >= 8 {
+		chunks := stringToUint64Slice(s)
+		for _, n := range chunks {
+			// combine masks before checking for the MSB of each byte. We include
+			// `n` in the mask to check whether any of the *input* byte MSBs were
+			// set (i.e. the byte was outside the ASCII range).
+			mask := n | (n - (lsb * 0x20)) |
+				((n ^ (lsb * '"')) - lsb) |
+				((n ^ (lsb * '\\')) - lsb)
+			if (mask & msb) != 0 {
+				j = bits.TrailingZeros64(mask&msb) / 8
+				goto ESCAPE_END
+			}
+		}
+		valLen := len(s)
+		for i := len(chunks) * 8; i < valLen; i++ {
+			if needEscape[s[i]] {
+				j = i
+				goto ESCAPE_END
+			}
+		}
+		return append(append(buf, s...), '"')
+	}
+ESCAPE_END:
+	for j < valLen {
+		c := s[j]
+
+		if !needEscape[c] {
+			// fast path: most of the time, printable ascii characters are used
+			j++
+			continue
+		}
+
+		switch c {
+		case '\\', '"':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', c)
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\n':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'n')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\r':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 'r')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case '\t':
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, '\\', 't')
+			i = j + 1
+			j = j + 1
+			continue
+
+		case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
+			0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
+			buf = append(buf, s[i:j]...)
+			buf = append(buf, `\u00`...)
+			buf = append(buf, hex[c>>4], hex[c&0xF])
+			i = j + 1
+			j = j + 1
+			continue
+		}
+		j++
+	}
+
+	return append(append(buf, s[i:]...), '"')
+}

internal/encoder/string_table.go

@@ -0,0 +1,415 @@
+package encoder
+
+var needEscapeHTMLNormalizeUTF8 = [256]bool{
+	'"':  true,
+	'&':  true,
+	'<':  true,
+	'>':  true,
+	'\\': true,
+	0x00: true,
+	0x01: true,
+	0x02: true,
+	0x03: true,
+	0x04: true,
+	0x05: true,
+	0x06: true,
+	0x07: true,
+	0x08: true,
+	0x09: true,
+	0x0a: true,
+	0x0b: true,
+	0x0c: true,
+	0x0d: true,
+	0x0e: true,
+	0x0f: true,
+	0x10: true,
+	0x11: true,
+	0x12: true,
+	0x13: true,
+	0x14: true,
+	0x15: true,
+	0x16: true,
+	0x17: true,
+	0x18: true,
+	0x19: true,
+	0x1a: true,
+	0x1b: true,
+	0x1c: true,
+	0x1d: true,
+	0x1e: true,
+	0x1f: true,
+	/* 0x20 - 0x7f */
+	0x80: true,
+	0x81: true,
+	0x82: true,
+	0x83: true,
+	0x84: true,
+	0x85: true,
+	0x86: true,
+	0x87: true,
+	0x88: true,
+	0x89: true,
+	0x8a: true,
+	0x8b: true,
+	0x8c: true,
+	0x8d: true,
+	0x8e: true,
+	0x8f: true,
+	0x90: true,
+	0x91: true,
+	0x92: true,
+	0x93: true,
+	0x94: true,
+	0x95: true,
+	0x96: true,
+	0x97: true,
+	0x98: true,
+	0x99: true,
+	0x9a: true,
+	0x9b: true,
+	0x9c: true,
+	0x9d: true,
+	0x9e: true,
+	0x9f: true,
+	0xa0: true,
+	0xa1: true,
+	0xa2: true,
+	0xa3: true,
+	0xa4: true,
+	0xa5: true,
+	0xa6: true,
+	0xa7: true,
+	0xa8: true,
+	0xa9: true,
+	0xaa: true,
+	0xab: true,
+	0xac: true,
+	0xad: true,
+	0xae: true,
+	0xaf: true,
+	0xb0: true,
+	0xb1: true,
+	0xb2: true,
+	0xb3: true,
+	0xb4: true,
+	0xb5: true,
+	0xb6: true,
+	0xb7: true,
+	0xb8: true,
+	0xb9: true,
+	0xba: true,
+	0xbb: true,
+	0xbc: true,
+	0xbd: true,
+	0xbe: true,
+	0xbf: true,
+	0xc0: true,
+	0xc1: true,
+	0xc2: true,
+	0xc3: true,
+	0xc4: true,
+	0xc5: true,
+	0xc6: true,
+	0xc7: true,
+	0xc8: true,
+	0xc9: true,
+	0xca: true,
+	0xcb: true,
+	0xcc: true,
+	0xcd: true,
+	0xce: true,
+	0xcf: true,
+	0xd0: true,
+	0xd1: true,
+	0xd2: true,
+	0xd3: true,
+	0xd4: true,
+	0xd5: true,
+	0xd6: true,
+	0xd7: true,
+	0xd8: true,
+	0xd9: true,
+	0xda: true,
+	0xdb: true,
+	0xdc: true,
+	0xdd: true,
+	0xde: true,
+	0xdf: true,
+	0xe0: true,
+	0xe1: true,
+	0xe2: true,
+	0xe3: true,
+	0xe4: true,
+	0xe5: true,
+	0xe6: true,
+	0xe7: true,
+	0xe8: true,
+	0xe9: true,
+	0xea: true,
+	0xeb: true,
+	0xec: true,
+	0xed: true,
+	0xee: true,
+	0xef: true,
+	0xf0: true,
+	0xf1: true,
+	0xf2: true,
+	0xf3: true,
+	0xf4: true,
+	0xf5: true,
+	0xf6: true,
+	0xf7: true,
+	0xf8: true,
+	0xf9: true,
+	0xfa: true,
+	0xfb: true,
+	0xfc: true,
+	0xfd: true,
+	0xfe: true,
+	0xff: true,
+}
+
+var needEscapeNormalizeUTF8 = [256]bool{
+	'"':  true,
+	'\\': true,
+	0x00: true,
+	0x01: true,
+	0x02: true,
+	0x03: true,
+	0x04: true,
+	0x05: true,
+	0x06: true,
+	0x07: true,
+	0x08: true,
+	0x09: true,
+	0x0a: true,
+	0x0b: true,
+	0x0c: true,
+	0x0d: true,
+	0x0e: true,
+	0x0f: true,
+	0x10: true,
+	0x11: true,
+	0x12: true,
+	0x13: true,
+	0x14: true,
+	0x15: true,
+	0x16: true,
+	0x17: true,
+	0x18: true,
+	0x19: true,
+	0x1a: true,
+	0x1b: true,
+	0x1c: true,
+	0x1d: true,
+	0x1e: true,
+	0x1f: true,
+	/* 0x20 - 0x7f */
+	0x80: true,
+	0x81: true,
+	0x82: true,
+	0x83: true,
+	0x84: true,
+	0x85: true,
+	0x86: true,
+	0x87: true,
+	0x88: true,
+	0x89: true,
+	0x8a: true,
+	0x8b: true,
+	0x8c: true,
+	0x8d: true,
+	0x8e: true,
+	0x8f: true,
+	0x90: true,
+	0x91: true,
+	0x92: true,
+	0x93: true,
+	0x94: true,
+	0x95: true,
+	0x96: true,
+	0x97: true,
+	0x98: true,
+	0x99: true,
+	0x9a: true,
+	0x9b: true,
+	0x9c: true,
+	0x9d: true,
+	0x9e: true,
+	0x9f: true,
+	0xa0: true,
+	0xa1: true,
+	0xa2: true,
+	0xa3: true,
+	0xa4: true,
+	0xa5: true,
+	0xa6: true,
+	0xa7: true,
+	0xa8: true,
+	0xa9: true,
+	0xaa: true,
+	0xab: true,
+	0xac: true,
+	0xad: true,
+	0xae: true,
+	0xaf: true,
+	0xb0: true,
+	0xb1: true,
+	0xb2: true,
+	0xb3: true,
+	0xb4: true,
+	0xb5: true,
+	0xb6: true,
+	0xb7: true,
+	0xb8: true,
+	0xb9: true,
+	0xba: true,
+	0xbb: true,
+	0xbc: true,
+	0xbd: true,
+	0xbe: true,
+	0xbf: true,
+	0xc0: true,
+	0xc1: true,
+	0xc2: true,
+	0xc3: true,
+	0xc4: true,
+	0xc5: true,
+	0xc6: true,
+	0xc7: true,
+	0xc8: true,
+	0xc9: true,
+	0xca: true,
+	0xcb: true,
+	0xcc: true,
+	0xcd: true,
+	0xce: true,
+	0xcf: true,
+	0xd0: true,
+	0xd1: true,
+	0xd2: true,
+	0xd3: true,
+	0xd4: true,
+	0xd5: true,
+	0xd6: true,
+	0xd7: true,
+	0xd8: true,
+	0xd9: true,
+	0xda: true,
+	0xdb: true,
+	0xdc: true,
+	0xdd: true,
+	0xde: true,
+	0xdf: true,
+	0xe0: true,
+	0xe1: true,
+	0xe2: true,
+	0xe3: true,
+	0xe4: true,
+	0xe5: true,
+	0xe6: true,
+	0xe7: true,
+	0xe8: true,
+	0xe9: true,
+	0xea: true,
+	0xeb: true,
+	0xec: true,
+	0xed: true,
+	0xee: true,
+	0xef: true,
+	0xf0: true,
+	0xf1: true,
+	0xf2: true,
+	0xf3: true,
+	0xf4: true,
+	0xf5: true,
+	0xf6: true,
+	0xf7: true,
+	0xf8: true,
+	0xf9: true,
+	0xfa: true,
+	0xfb: true,
+	0xfc: true,
+	0xfd: true,
+	0xfe: true,
+	0xff: true,
+}
+
+var needEscapeHTML = [256]bool{
+	'"':  true,
+	'&':  true,
+	'<':  true,
+	'>':  true,
+	'\\': true,
+	0x00: true,
+	0x01: true,
+	0x02: true,
+	0x03: true,
+	0x04: true,
+	0x05: true,
+	0x06: true,
+	0x07: true,
+	0x08: true,
+	0x09: true,
+	0x0a: true,
+	0x0b: true,
+	0x0c: true,
+	0x0d: true,
+	0x0e: true,
+	0x0f: true,
+	0x10: true,
+	0x11: true,
+	0x12: true,
+	0x13: true,
+	0x14: true,
+	0x15: true,
+	0x16: true,
+	0x17: true,
+	0x18: true,
+	0x19: true,
+	0x1a: true,
+	0x1b: true,
+	0x1c: true,
+	0x1d: true,
+	0x1e: true,
+	0x1f: true,
+	/* 0x20 - 0xff */
+}
+
+var needEscape = [256]bool{
+	'"':  true,
+	'\\': true,
+	0x00: true,
+	0x01: true,
+	0x02: true,
+	0x03: true,
+	0x04: true,
+	0x05: true,
+	0x06: true,
+	0x07: true,
+	0x08: true,
+	0x09: true,
+	0x0a: true,
+	0x0b: true,
+	0x0c: true,
+	0x0d: true,
+	0x0e: true,
+	0x0f: true,
+	0x10: true,
+	0x11: true,
+	0x12: true,
+	0x13: true,
+	0x14: true,
+	0x15: true,
+	0x16: true,
+	0x17: true,
+	0x18: true,
+	0x19: true,
+	0x1a: true,
+	0x1b: true,
+	0x1c: true,
+	0x1d: true,
+	0x1e: true,
+	0x1f: true,
+	/* 0x20 - 0xff */
+}

internal/encoder/vm/debug_vm.go

@@ -0,0 +1,41 @@
+package vm
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/goccy/go-json/internal/encoder"
+)
+
+func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
+	defer func() {
+		var code *encoder.Opcode
+		if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
+			code = codeSet.EscapeKeyCode
+		} else {
+			code = codeSet.NoescapeKeyCode
+		}
+		if wc := ctx.Option.DebugDOTOut; wc != nil {
+			_, _ = io.WriteString(wc, code.DumpDOT())
+			wc.Close()
+			ctx.Option.DebugDOTOut = nil
+		}
+
+		if err := recover(); err != nil {
+			w := ctx.Option.DebugOut
+			fmt.Fprintln(w, "=============[DEBUG]===============")
+			fmt.Fprintln(w, "* [TYPE]")
+			fmt.Fprintln(w, codeSet.Type)
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [ALL OPCODE]")
+			fmt.Fprintln(w, code.Dump())
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [CONTEXT]")
+			fmt.Fprintf(w, "%+v\n", ctx)
+			fmt.Fprintln(w, "===================================")
+			panic(err)
+		}
+	}()
+
+	return Run(ctx, b, codeSet)
+}

internal/encoder/vm/hack.go

@@ -0,0 +1,9 @@
+package vm
+
+import (
+	// HACK: compile order
+	// `vm`, `vm_indent`, `vm_color`, `vm_color_indent` packages uses a lot of memory to compile,
+	// so forcibly make dependencies and avoid compiling in concurrent.
+	// dependency order: vm => vm_indent => vm_color => vm_color_indent
+	_ "github.com/goccy/go-json/internal/encoder/vm_indent"
+)

internal/encoder/vm/util.go

@@ -0,0 +1,207 @@
+package vm
+
+import (
+	"encoding/json"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/encoder"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+const uintptrSize = 4 << (^uintptr(0) >> 63)
+
+var (
+	appendInt           = encoder.AppendInt
+	appendUint          = encoder.AppendUint
+	appendFloat32       = encoder.AppendFloat32
+	appendFloat64       = encoder.AppendFloat64
+	appendString        = encoder.AppendString
+	appendByteSlice     = encoder.AppendByteSlice
+	appendNumber        = encoder.AppendNumber
+	errUnsupportedValue = encoder.ErrUnsupportedValue
+	errUnsupportedFloat = encoder.ErrUnsupportedFloat
+	mapiterinit         = encoder.MapIterInit
+	mapiterkey          = encoder.MapIterKey
+	mapitervalue        = encoder.MapIterValue
+	mapiternext         = encoder.MapIterNext
+	maplen              = encoder.MapLen
+)
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+type nonEmptyInterface struct {
+	itab *struct {
+		ityp *runtime.Type // static interface type
+		typ  *runtime.Type // dynamic concrete type
+		// unused fields...
+	}
+	ptr unsafe.Pointer
+}
+
+func errUnimplementedOp(op encoder.OpType) error {
+	return fmt.Errorf("encoder: opcode %s has not been implemented", op)
+}
+
+func load(base uintptr, idx uint32) uintptr {
+	addr := base + uintptr(idx)
+	return **(**uintptr)(unsafe.Pointer(&addr))
+}
+
+func store(base uintptr, idx uint32, p uintptr) {
+	addr := base + uintptr(idx)
+	**(**uintptr)(unsafe.Pointer(&addr)) = p
+}
+
+func loadNPtr(base uintptr, idx uint32, ptrNum uint8) uintptr {
+	addr := base + uintptr(idx)
+	p := **(**uintptr)(unsafe.Pointer(&addr))
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUint64(p uintptr, bitSize uint8) uint64 {
+	switch bitSize {
+	case 8:
+		return (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		return (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		return (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		return **(**uint64)(unsafe.Pointer(&p))
+	}
+	return 0
+}
+func ptrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
+func ptrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
+func ptrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
+func ptrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
+func ptrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
+func ptrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
+func ptrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
+func ptrToPtr(p uintptr) uintptr {
+	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
+}
+func ptrToNPtr(p uintptr, ptrNum uint8) uintptr {
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUnsafePtr(p uintptr) unsafe.Pointer {
+	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
+}
+func ptrToInterface(code *encoder.Opcode, p uintptr) interface{} {
+	return *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+}
+
+func appendBool(_ *encoder.RuntimeContext, b []byte, v bool) []byte {
+	if v {
+		return append(b, "true"...)
+	}
+	return append(b, "false"...)
+}
+
+func appendNull(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, "null"...)
+}
+
+func appendComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, ',')
+}
+
+func appendNullComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, "null,"...)
+}
+
+func appendColon(_ *encoder.RuntimeContext, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = ':'
+	return b
+}
+
+func appendMapKeyValue(_ *encoder.RuntimeContext, _ *encoder.Opcode, b, key, value []byte) []byte {
+	b = append(b, key...)
+	b[len(b)-1] = ':'
+	return append(b, value...)
+}
+
+func appendMapEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	b[len(b)-1] = '}'
+	b = append(b, ',')
+	return b
+}
+
+func appendMarshalJSON(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalJSON(ctx, code, b, v)
+}
+
+func appendMarshalText(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalText(ctx, code, b, v)
+}
+
+func appendArrayHead(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	return append(b, '[')
+}
+
+func appendArrayEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = ']'
+	return append(b, ',')
+}
+
+func appendEmptyArray(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '[', ']', ',')
+}
+
+func appendEmptyObject(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '}', ',')
+}
+
+func appendObjectEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = '}'
+	return append(b, ',')
+}
+
+func appendStructHead(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{')
+}
+
+func appendStructKey(_ *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	return append(b, code.Key...)
+}
+
+func appendStructEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	return append(b, '}', ',')
+}
+
+func appendStructEndSkipLast(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	if b[last] == ',' {
+		b[last] = '}'
+		return appendComma(ctx, b)
+	}
+	return appendStructEnd(ctx, code, b)
+}
+
+func restoreIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, _ uintptr)               {}
+func storeIndent(_ uintptr, _ *encoder.Opcode, _ uintptr)                                 {}
+func appendMapKeyIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte    { return b }
+func appendArrayElemIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte { return b }

internal/encoder/vm_color/debug_vm.go

@@ -0,0 +1,35 @@
+package vm_color
+
+import (
+	"fmt"
+
+	"github.com/goccy/go-json/internal/encoder"
+)
+
+func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
+	var code *encoder.Opcode
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
+		code = codeSet.EscapeKeyCode
+	} else {
+		code = codeSet.NoescapeKeyCode
+	}
+
+	defer func() {
+		if err := recover(); err != nil {
+			w := ctx.Option.DebugOut
+			fmt.Fprintln(w, "=============[DEBUG]===============")
+			fmt.Fprintln(w, "* [TYPE]")
+			fmt.Fprintln(w, codeSet.Type)
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [ALL OPCODE]")
+			fmt.Fprintln(w, code.Dump())
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [CONTEXT]")
+			fmt.Fprintf(w, "%+v\n", ctx)
+			fmt.Fprintln(w, "===================================")
+			panic(err)
+		}
+	}()
+
+	return Run(ctx, b, codeSet)
+}

internal/encoder/vm_color/hack.go

@@ -0,0 +1,9 @@
+package vm_color
+
+import (
+	// HACK: compile order
+	// `vm`, `vm_indent`, `vm_color`, `vm_color_indent` packages uses a lot of memory to compile,
+	// so forcibly make dependencies and avoid compiling in concurrent.
+	// dependency order: vm => vm_indent => vm_color => vm_color_indent
+	_ "github.com/goccy/go-json/internal/encoder/vm_color_indent"
+)

internal/encoder/vm_color/util.go

@@ -0,0 +1,274 @@
+package vm_color
+
+import (
+	"encoding/json"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/encoder"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+const uintptrSize = 4 << (^uintptr(0) >> 63)
+
+var (
+	errUnsupportedValue = encoder.ErrUnsupportedValue
+	errUnsupportedFloat = encoder.ErrUnsupportedFloat
+	mapiterinit         = encoder.MapIterInit
+	mapiterkey          = encoder.MapIterKey
+	mapitervalue        = encoder.MapIterValue
+	mapiternext         = encoder.MapIterNext
+	maplen              = encoder.MapLen
+)
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+type nonEmptyInterface struct {
+	itab *struct {
+		ityp *runtime.Type // static interface type
+		typ  *runtime.Type // dynamic concrete type
+		// unused fields...
+	}
+	ptr unsafe.Pointer
+}
+
+func errUnimplementedOp(op encoder.OpType) error {
+	return fmt.Errorf("encoder: opcode %s has not been implemented", op)
+}
+
+func load(base uintptr, idx uint32) uintptr {
+	addr := base + uintptr(idx)
+	return **(**uintptr)(unsafe.Pointer(&addr))
+}
+
+func store(base uintptr, idx uint32, p uintptr) {
+	addr := base + uintptr(idx)
+	**(**uintptr)(unsafe.Pointer(&addr)) = p
+}
+
+func loadNPtr(base uintptr, idx uint32, ptrNum uint8) uintptr {
+	addr := base + uintptr(idx)
+	p := **(**uintptr)(unsafe.Pointer(&addr))
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUint64(p uintptr, bitSize uint8) uint64 {
+	switch bitSize {
+	case 8:
+		return (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		return (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		return (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		return **(**uint64)(unsafe.Pointer(&p))
+	}
+	return 0
+}
+func ptrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
+func ptrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
+func ptrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
+func ptrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
+func ptrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
+func ptrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
+func ptrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
+func ptrToPtr(p uintptr) uintptr {
+	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
+}
+func ptrToNPtr(p uintptr, ptrNum uint8) uintptr {
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUnsafePtr(p uintptr) unsafe.Pointer {
+	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
+}
+func ptrToInterface(code *encoder.Opcode, p uintptr) interface{} {
+	return *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+}
+
+func appendInt(ctx *encoder.RuntimeContext, b []byte, p uintptr, code *encoder.Opcode) []byte {
+	format := ctx.Option.ColorScheme.Int
+	b = append(b, format.Header...)
+	b = encoder.AppendInt(ctx, b, p, code)
+	return append(b, format.Footer...)
+}
+
+func appendUint(ctx *encoder.RuntimeContext, b []byte, p uintptr, code *encoder.Opcode) []byte {
+	format := ctx.Option.ColorScheme.Uint
+	b = append(b, format.Header...)
+	b = encoder.AppendUint(ctx, b, p, code)
+	return append(b, format.Footer...)
+}
+
+func appendFloat32(ctx *encoder.RuntimeContext, b []byte, v float32) []byte {
+	format := ctx.Option.ColorScheme.Float
+	b = append(b, format.Header...)
+	b = encoder.AppendFloat32(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendFloat64(ctx *encoder.RuntimeContext, b []byte, v float64) []byte {
+	format := ctx.Option.ColorScheme.Float
+	b = append(b, format.Header...)
+	b = encoder.AppendFloat64(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendString(ctx *encoder.RuntimeContext, b []byte, v string) []byte {
+	format := ctx.Option.ColorScheme.String
+	b = append(b, format.Header...)
+	b = encoder.AppendString(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendByteSlice(ctx *encoder.RuntimeContext, b []byte, src []byte) []byte {
+	format := ctx.Option.ColorScheme.Binary
+	b = append(b, format.Header...)
+	b = encoder.AppendByteSlice(ctx, b, src)
+	return append(b, format.Footer...)
+}
+
+func appendNumber(ctx *encoder.RuntimeContext, b []byte, n json.Number) ([]byte, error) {
+	format := ctx.Option.ColorScheme.Int
+	b = append(b, format.Header...)
+	bb, err := encoder.AppendNumber(ctx, b, n)
+	if err != nil {
+		return nil, err
+	}
+	return append(bb, format.Footer...), nil
+}
+
+func appendBool(ctx *encoder.RuntimeContext, b []byte, v bool) []byte {
+	format := ctx.Option.ColorScheme.Bool
+	b = append(b, format.Header...)
+	if v {
+		b = append(b, "true"...)
+	} else {
+		b = append(b, "false"...)
+	}
+	return append(b, format.Footer...)
+}
+
+func appendNull(ctx *encoder.RuntimeContext, b []byte) []byte {
+	format := ctx.Option.ColorScheme.Null
+	b = append(b, format.Header...)
+	b = append(b, "null"...)
+	return append(b, format.Footer...)
+}
+
+func appendComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, ',')
+}
+
+func appendNullComma(ctx *encoder.RuntimeContext, b []byte) []byte {
+	format := ctx.Option.ColorScheme.Null
+	b = append(b, format.Header...)
+	b = append(b, "null"...)
+	return append(append(b, format.Footer...), ',')
+}
+
+func appendColon(_ *encoder.RuntimeContext, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = ':'
+	return b
+}
+
+func appendMapKeyValue(_ *encoder.RuntimeContext, _ *encoder.Opcode, b, key, value []byte) []byte {
+	b = append(b, key[:len(key)-1]...)
+	b = append(b, ':')
+	return append(b, value...)
+}
+
+func appendMapEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = '}'
+	b = append(b, ',')
+	return b
+}
+
+func appendMarshalJSON(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalJSON(ctx, code, b, v)
+}
+
+func appendMarshalText(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	format := ctx.Option.ColorScheme.String
+	b = append(b, format.Header...)
+	bb, err := encoder.AppendMarshalText(ctx, code, b, v)
+	if err != nil {
+		return nil, err
+	}
+	return append(bb, format.Footer...), nil
+}
+
+func appendArrayHead(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	return append(b, '[')
+}
+
+func appendArrayEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = ']'
+	return append(b, ',')
+}
+
+func appendEmptyArray(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '[', ']', ',')
+}
+
+func appendEmptyObject(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '}', ',')
+}
+
+func appendObjectEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	b[last] = '}'
+	return append(b, ',')
+}
+
+func appendStructHead(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{')
+}
+
+func appendStructKey(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	format := ctx.Option.ColorScheme.ObjectKey
+	b = append(b, format.Header...)
+	b = append(b, code.Key[:len(code.Key)-1]...)
+	b = append(b, format.Footer...)
+
+	return append(b, ':')
+}
+
+func appendStructEnd(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte {
+	return append(b, '}', ',')
+}
+
+func appendStructEndSkipLast(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	if b[last] == ',' {
+		b[last] = '}'
+		return appendComma(ctx, b)
+	}
+	return appendStructEnd(ctx, code, b)
+}
+
+func restoreIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, _ uintptr)               {}
+func storeIndent(_ uintptr, _ *encoder.Opcode, _ uintptr)                                 {}
+func appendMapKeyIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte    { return b }
+func appendArrayElemIndent(_ *encoder.RuntimeContext, _ *encoder.Opcode, b []byte) []byte { return b }

internal/encoder/vm_color_indent/debug_vm.go

@@ -0,0 +1,35 @@
+package vm_color_indent
+
+import (
+	"fmt"
+
+	"github.com/goccy/go-json/internal/encoder"
+)
+
+func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
+	var code *encoder.Opcode
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
+		code = codeSet.EscapeKeyCode
+	} else {
+		code = codeSet.NoescapeKeyCode
+	}
+
+	defer func() {
+		if err := recover(); err != nil {
+			w := ctx.Option.DebugOut
+			fmt.Fprintln(w, "=============[DEBUG]===============")
+			fmt.Fprintln(w, "* [TYPE]")
+			fmt.Fprintln(w, codeSet.Type)
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [ALL OPCODE]")
+			fmt.Fprintln(w, code.Dump())
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [CONTEXT]")
+			fmt.Fprintf(w, "%+v\n", ctx)
+			fmt.Fprintln(w, "===================================")
+			panic(err)
+		}
+	}()
+
+	return Run(ctx, b, codeSet)
+}

internal/encoder/vm_color_indent/util.go

@@ -0,0 +1,297 @@
+package vm_color_indent
+
+import (
+	"encoding/json"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/encoder"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+const uintptrSize = 4 << (^uintptr(0) >> 63)
+
+var (
+	appendIndent        = encoder.AppendIndent
+	appendStructEnd     = encoder.AppendStructEndIndent
+	errUnsupportedValue = encoder.ErrUnsupportedValue
+	errUnsupportedFloat = encoder.ErrUnsupportedFloat
+	mapiterinit         = encoder.MapIterInit
+	mapiterkey          = encoder.MapIterKey
+	mapitervalue        = encoder.MapIterValue
+	mapiternext         = encoder.MapIterNext
+	maplen              = encoder.MapLen
+)
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+type nonEmptyInterface struct {
+	itab *struct {
+		ityp *runtime.Type // static interface type
+		typ  *runtime.Type // dynamic concrete type
+		// unused fields...
+	}
+	ptr unsafe.Pointer
+}
+
+func errUnimplementedOp(op encoder.OpType) error {
+	return fmt.Errorf("encoder (indent): opcode %s has not been implemented", op)
+}
+
+func load(base uintptr, idx uint32) uintptr {
+	addr := base + uintptr(idx)
+	return **(**uintptr)(unsafe.Pointer(&addr))
+}
+
+func store(base uintptr, idx uint32, p uintptr) {
+	addr := base + uintptr(idx)
+	**(**uintptr)(unsafe.Pointer(&addr)) = p
+}
+
+func loadNPtr(base uintptr, idx uint32, ptrNum uint8) uintptr {
+	addr := base + uintptr(idx)
+	p := **(**uintptr)(unsafe.Pointer(&addr))
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUint64(p uintptr, bitSize uint8) uint64 {
+	switch bitSize {
+	case 8:
+		return (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		return (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		return (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		return **(**uint64)(unsafe.Pointer(&p))
+	}
+	return 0
+}
+
+func ptrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
+func ptrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
+func ptrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
+func ptrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
+func ptrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
+func ptrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
+func ptrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
+func ptrToPtr(p uintptr) uintptr {
+	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
+}
+func ptrToNPtr(p uintptr, ptrNum uint8) uintptr {
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUnsafePtr(p uintptr) unsafe.Pointer {
+	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
+}
+func ptrToInterface(code *encoder.Opcode, p uintptr) interface{} {
+	return *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+}
+
+func appendInt(ctx *encoder.RuntimeContext, b []byte, p uintptr, code *encoder.Opcode) []byte {
+	format := ctx.Option.ColorScheme.Int
+	b = append(b, format.Header...)
+	b = encoder.AppendInt(ctx, b, p, code)
+	return append(b, format.Footer...)
+}
+
+func appendUint(ctx *encoder.RuntimeContext, b []byte, p uintptr, code *encoder.Opcode) []byte {
+	format := ctx.Option.ColorScheme.Uint
+	b = append(b, format.Header...)
+	b = encoder.AppendUint(ctx, b, p, code)
+	return append(b, format.Footer...)
+}
+
+func appendFloat32(ctx *encoder.RuntimeContext, b []byte, v float32) []byte {
+	format := ctx.Option.ColorScheme.Float
+	b = append(b, format.Header...)
+	b = encoder.AppendFloat32(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendFloat64(ctx *encoder.RuntimeContext, b []byte, v float64) []byte {
+	format := ctx.Option.ColorScheme.Float
+	b = append(b, format.Header...)
+	b = encoder.AppendFloat64(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendString(ctx *encoder.RuntimeContext, b []byte, v string) []byte {
+	format := ctx.Option.ColorScheme.String
+	b = append(b, format.Header...)
+	b = encoder.AppendString(ctx, b, v)
+	return append(b, format.Footer...)
+}
+
+func appendByteSlice(ctx *encoder.RuntimeContext, b []byte, src []byte) []byte {
+	format := ctx.Option.ColorScheme.Binary
+	b = append(b, format.Header...)
+	b = encoder.AppendByteSlice(ctx, b, src)
+	return append(b, format.Footer...)
+}
+
+func appendNumber(ctx *encoder.RuntimeContext, b []byte, n json.Number) ([]byte, error) {
+	format := ctx.Option.ColorScheme.Int
+	b = append(b, format.Header...)
+	bb, err := encoder.AppendNumber(ctx, b, n)
+	if err != nil {
+		return nil, err
+	}
+	return append(bb, format.Footer...), nil
+}
+
+func appendBool(ctx *encoder.RuntimeContext, b []byte, v bool) []byte {
+	format := ctx.Option.ColorScheme.Bool
+	b = append(b, format.Header...)
+	if v {
+		b = append(b, "true"...)
+	} else {
+		b = append(b, "false"...)
+	}
+	return append(b, format.Footer...)
+}
+
+func appendNull(ctx *encoder.RuntimeContext, b []byte) []byte {
+	format := ctx.Option.ColorScheme.Null
+	b = append(b, format.Header...)
+	b = append(b, "null"...)
+	return append(b, format.Footer...)
+}
+
+func appendComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, ',', '\n')
+}
+
+func appendNullComma(ctx *encoder.RuntimeContext, b []byte) []byte {
+	format := ctx.Option.ColorScheme.Null
+	b = append(b, format.Header...)
+	b = append(b, "null"...)
+	return append(append(b, format.Footer...), ',', '\n')
+}
+
+func appendColon(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b[:len(b)-2], ':', ' ')
+}
+
+func appendMapKeyValue(ctx *encoder.RuntimeContext, code *encoder.Opcode, b, key, value []byte) []byte {
+	b = appendIndent(ctx, b, code.Indent+1)
+	b = append(b, key...)
+	b[len(b)-2] = ':'
+	b[len(b)-1] = ' '
+	return append(b, value...)
+}
+
+func appendMapEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = b[:len(b)-2]
+	b = append(b, '\n')
+	b = appendIndent(ctx, b, code.Indent)
+	return append(b, '}', ',', '\n')
+}
+
+func appendArrayHead(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = append(b, '[', '\n')
+	return appendIndent(ctx, b, code.Indent+1)
+}
+
+func appendArrayEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = b[:len(b)-2]
+	b = append(b, '\n')
+	b = appendIndent(ctx, b, code.Indent)
+	return append(b, ']', ',', '\n')
+}
+
+func appendEmptyArray(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '[', ']', ',', '\n')
+}
+
+func appendEmptyObject(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '}', ',', '\n')
+}
+
+func appendObjectEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	// replace comma to newline
+	b[last-1] = '\n'
+	b = appendIndent(ctx, b[:last], code.Indent)
+	return append(b, '}', ',', '\n')
+}
+
+func appendMarshalJSON(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalJSONIndent(ctx, code, b, v)
+}
+
+func appendMarshalText(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	format := ctx.Option.ColorScheme.String
+	b = append(b, format.Header...)
+	bb, err := encoder.AppendMarshalTextIndent(ctx, code, b, v)
+	if err != nil {
+		return nil, err
+	}
+	return append(bb, format.Footer...), nil
+}
+
+func appendStructHead(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '\n')
+}
+
+func appendStructKey(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = appendIndent(ctx, b, code.Indent)
+
+	format := ctx.Option.ColorScheme.ObjectKey
+	b = append(b, format.Header...)
+	b = append(b, code.Key[:len(code.Key)-1]...)
+	b = append(b, format.Footer...)
+
+	return append(b, ':', ' ')
+}
+
+func appendStructEndSkipLast(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	if b[last-1] == '{' {
+		b[last] = '}'
+	} else {
+		if b[last] == '\n' {
+			// to remove ',' and '\n' characters
+			b = b[:len(b)-2]
+		}
+		b = append(b, '\n')
+		b = appendIndent(ctx, b, code.Indent-1)
+		b = append(b, '}')
+	}
+	return appendComma(ctx, b)
+}
+
+func restoreIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, ctxptr uintptr) {
+	ctx.BaseIndent = uint32(load(ctxptr, code.Length))
+}
+
+func storeIndent(ctxptr uintptr, code *encoder.Opcode, indent uintptr) {
+	store(ctxptr, code.Length, indent)
+}
+
+func appendArrayElemIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	return appendIndent(ctx, b, code.Indent+1)
+}
+
+func appendMapKeyIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	return appendIndent(ctx, b, code.Indent)
+}

internal/encoder/vm_indent/debug_vm.go

@@ -0,0 +1,35 @@
+package vm_indent
+
+import (
+	"fmt"
+
+	"github.com/goccy/go-json/internal/encoder"
+)
+
+func DebugRun(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]byte, error) {
+	var code *encoder.Opcode
+	if (ctx.Option.Flag & encoder.HTMLEscapeOption) != 0 {
+		code = codeSet.EscapeKeyCode
+	} else {
+		code = codeSet.NoescapeKeyCode
+	}
+
+	defer func() {
+		if err := recover(); err != nil {
+			w := ctx.Option.DebugOut
+			fmt.Fprintln(w, "=============[DEBUG]===============")
+			fmt.Fprintln(w, "* [TYPE]")
+			fmt.Fprintln(w, codeSet.Type)
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [ALL OPCODE]")
+			fmt.Fprintln(w, code.Dump())
+			fmt.Fprintf(w, "\n")
+			fmt.Fprintln(w, "* [CONTEXT]")
+			fmt.Fprintf(w, "%+v\n", ctx)
+			fmt.Fprintln(w, "===================================")
+			panic(err)
+		}
+	}()
+
+	return Run(ctx, b, codeSet)
+}

internal/encoder/vm_indent/hack.go

@@ -0,0 +1,9 @@
+package vm_indent
+
+import (
+	// HACK: compile order
+	// `vm`, `vm_indent`, `vm_color`, `vm_color_indent` packages uses a lot of memory to compile,
+	// so forcibly make dependencies and avoid compiling in concurrent.
+	// dependency order: vm => vm_indent => vm_color => vm_color_indent
+	_ "github.com/goccy/go-json/internal/encoder/vm_color"
+)

internal/encoder/vm_indent/util.go

@@ -0,0 +1,230 @@
+package vm_indent
+
+import (
+	"encoding/json"
+	"fmt"
+	"unsafe"
+
+	"github.com/goccy/go-json/internal/encoder"
+	"github.com/goccy/go-json/internal/runtime"
+)
+
+const uintptrSize = 4 << (^uintptr(0) >> 63)
+
+var (
+	appendInt           = encoder.AppendInt
+	appendUint          = encoder.AppendUint
+	appendFloat32       = encoder.AppendFloat32
+	appendFloat64       = encoder.AppendFloat64
+	appendString        = encoder.AppendString
+	appendByteSlice     = encoder.AppendByteSlice
+	appendNumber        = encoder.AppendNumber
+	appendStructEnd     = encoder.AppendStructEndIndent
+	appendIndent        = encoder.AppendIndent
+	errUnsupportedValue = encoder.ErrUnsupportedValue
+	errUnsupportedFloat = encoder.ErrUnsupportedFloat
+	mapiterinit         = encoder.MapIterInit
+	mapiterkey          = encoder.MapIterKey
+	mapitervalue        = encoder.MapIterValue
+	mapiternext         = encoder.MapIterNext
+	maplen              = encoder.MapLen
+)
+
+type emptyInterface struct {
+	typ *runtime.Type
+	ptr unsafe.Pointer
+}
+
+type nonEmptyInterface struct {
+	itab *struct {
+		ityp *runtime.Type // static interface type
+		typ  *runtime.Type // dynamic concrete type
+		// unused fields...
+	}
+	ptr unsafe.Pointer
+}
+
+func errUnimplementedOp(op encoder.OpType) error {
+	return fmt.Errorf("encoder (indent): opcode %s has not been implemented", op)
+}
+
+func load(base uintptr, idx uint32) uintptr {
+	addr := base + uintptr(idx)
+	return **(**uintptr)(unsafe.Pointer(&addr))
+}
+
+func store(base uintptr, idx uint32, p uintptr) {
+	addr := base + uintptr(idx)
+	**(**uintptr)(unsafe.Pointer(&addr)) = p
+}
+
+func loadNPtr(base uintptr, idx uint32, ptrNum uint8) uintptr {
+	addr := base + uintptr(idx)
+	p := **(**uintptr)(unsafe.Pointer(&addr))
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUint64(p uintptr, bitSize uint8) uint64 {
+	switch bitSize {
+	case 8:
+		return (uint64)(**(**uint8)(unsafe.Pointer(&p)))
+	case 16:
+		return (uint64)(**(**uint16)(unsafe.Pointer(&p)))
+	case 32:
+		return (uint64)(**(**uint32)(unsafe.Pointer(&p)))
+	case 64:
+		return **(**uint64)(unsafe.Pointer(&p))
+	}
+	return 0
+}
+func ptrToFloat32(p uintptr) float32            { return **(**float32)(unsafe.Pointer(&p)) }
+func ptrToFloat64(p uintptr) float64            { return **(**float64)(unsafe.Pointer(&p)) }
+func ptrToBool(p uintptr) bool                  { return **(**bool)(unsafe.Pointer(&p)) }
+func ptrToBytes(p uintptr) []byte               { return **(**[]byte)(unsafe.Pointer(&p)) }
+func ptrToNumber(p uintptr) json.Number         { return **(**json.Number)(unsafe.Pointer(&p)) }
+func ptrToString(p uintptr) string              { return **(**string)(unsafe.Pointer(&p)) }
+func ptrToSlice(p uintptr) *runtime.SliceHeader { return *(**runtime.SliceHeader)(unsafe.Pointer(&p)) }
+func ptrToPtr(p uintptr) uintptr {
+	return uintptr(**(**unsafe.Pointer)(unsafe.Pointer(&p)))
+}
+func ptrToNPtr(p uintptr, ptrNum uint8) uintptr {
+	for i := uint8(0); i < ptrNum; i++ {
+		if p == 0 {
+			return 0
+		}
+		p = ptrToPtr(p)
+	}
+	return p
+}
+
+func ptrToUnsafePtr(p uintptr) unsafe.Pointer {
+	return *(*unsafe.Pointer)(unsafe.Pointer(&p))
+}
+func ptrToInterface(code *encoder.Opcode, p uintptr) interface{} {
+	return *(*interface{})(unsafe.Pointer(&emptyInterface{
+		typ: code.Type,
+		ptr: *(*unsafe.Pointer)(unsafe.Pointer(&p)),
+	}))
+}
+
+func appendBool(_ *encoder.RuntimeContext, b []byte, v bool) []byte {
+	if v {
+		return append(b, "true"...)
+	}
+	return append(b, "false"...)
+}
+
+func appendNull(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, "null"...)
+}
+
+func appendComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, ',', '\n')
+}
+
+func appendNullComma(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, "null,\n"...)
+}
+
+func appendColon(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b[:len(b)-2], ':', ' ')
+}
+
+func appendMapKeyValue(ctx *encoder.RuntimeContext, code *encoder.Opcode, b, key, value []byte) []byte {
+	b = appendIndent(ctx, b, code.Indent+1)
+	b = append(b, key...)
+	b[len(b)-2] = ':'
+	b[len(b)-1] = ' '
+	return append(b, value...)
+}
+
+func appendMapEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = b[:len(b)-2]
+	b = append(b, '\n')
+	b = appendIndent(ctx, b, code.Indent)
+	return append(b, '}', ',', '\n')
+}
+
+func appendArrayHead(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = append(b, '[', '\n')
+	return appendIndent(ctx, b, code.Indent+1)
+}
+
+func appendArrayEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = b[:len(b)-2]
+	b = append(b, '\n')
+	b = appendIndent(ctx, b, code.Indent)
+	return append(b, ']', ',', '\n')
+}
+
+func appendEmptyArray(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '[', ']', ',', '\n')
+}
+
+func appendEmptyObject(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '}', ',', '\n')
+}
+
+func appendObjectEnd(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	// replace comma to newline
+	b[last-1] = '\n'
+	b = appendIndent(ctx, b[:last], code.Indent)
+	return append(b, '}', ',', '\n')
+}
+
+func appendMarshalJSON(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalJSONIndent(ctx, code, b, v)
+}
+
+func appendMarshalText(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte, v interface{}) ([]byte, error) {
+	return encoder.AppendMarshalTextIndent(ctx, code, b, v)
+}
+
+func appendStructHead(_ *encoder.RuntimeContext, b []byte) []byte {
+	return append(b, '{', '\n')
+}
+
+func appendStructKey(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	b = appendIndent(ctx, b, code.Indent)
+	b = append(b, code.Key...)
+	return append(b, ' ')
+}
+
+func appendStructEndSkipLast(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	last := len(b) - 1
+	if b[last-1] == '{' {
+		b[last] = '}'
+	} else {
+		if b[last] == '\n' {
+			// to remove ',' and '\n' characters
+			b = b[:len(b)-2]
+		}
+		b = append(b, '\n')
+		b = appendIndent(ctx, b, code.Indent-1)
+		b = append(b, '}')
+	}
+	return appendComma(ctx, b)
+}
+
+func restoreIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, ctxptr uintptr) {
+	ctx.BaseIndent = uint32(load(ctxptr, code.Length))
+}
+
+func storeIndent(ctxptr uintptr, code *encoder.Opcode, indent uintptr) {
+	store(ctxptr, code.Length, indent)
+}
+
+func appendArrayElemIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	return appendIndent(ctx, b, code.Indent+1)
+}
+
+func appendMapKeyIndent(ctx *encoder.RuntimeContext, code *encoder.Opcode, b []byte) []byte {
+	return appendIndent(ctx, b, code.Indent)
+}

internal/errors/error.go

@@ -0,0 +1,183 @@
+package errors
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+)
+
+type InvalidUTF8Error struct {
+	S string // the whole string value that caused the error
+}
+
+func (e *InvalidUTF8Error) Error() string {
+	return fmt.Sprintf("json: invalid UTF-8 in string: %s", strconv.Quote(e.S))
+}
+
+type InvalidUnmarshalError struct {
+	Type reflect.Type
+}
+
+func (e *InvalidUnmarshalError) Error() string {
+	if e.Type == nil {
+		return "json: Unmarshal(nil)"
+	}
+
+	if e.Type.Kind() != reflect.Ptr {
+		return fmt.Sprintf("json: Unmarshal(non-pointer %s)", e.Type)
+	}
+	return fmt.Sprintf("json: Unmarshal(nil %s)", e.Type)
+}
+
+// A MarshalerError represents an error from calling a MarshalJSON or MarshalText method.
+type MarshalerError struct {
+	Type       reflect.Type
+	Err        error
+	sourceFunc string
+}
+
+func (e *MarshalerError) Error() string {
+	srcFunc := e.sourceFunc
+	if srcFunc == "" {
+		srcFunc = "MarshalJSON"
+	}
+	return fmt.Sprintf("json: error calling %s for type %s: %s", srcFunc, e.Type, e.Err.Error())
+}
+
+// Unwrap returns the underlying error.
+func (e *MarshalerError) Unwrap() error { return e.Err }
+
+// A SyntaxError is a description of a JSON syntax error.
+type SyntaxError struct {
+	msg    string // description of error
+	Offset int64  // error occurred after reading Offset bytes
+}
+
+func (e *SyntaxError) Error() string { return e.msg }
+
+// An UnmarshalFieldError describes a JSON object key that
+// led to an unexported (and therefore unwritable) struct field.
+//
+// Deprecated: No longer used; kept for compatibility.
+type UnmarshalFieldError struct {
+	Key   string
+	Type  reflect.Type
+	Field reflect.StructField
+}
+
+func (e *UnmarshalFieldError) Error() string {
+	return fmt.Sprintf("json: cannot unmarshal object key %s into unexported field %s of type %s",
+		strconv.Quote(e.Key), e.Field.Name, e.Type.String(),
+	)
+}
+
+// An UnmarshalTypeError describes a JSON value that was
+// not appropriate for a value of a specific Go type.
+type UnmarshalTypeError struct {
+	Value  string       // description of JSON value - "bool", "array", "number -5"
+	Type   reflect.Type // type of Go value it could not be assigned to
+	Offset int64        // error occurred after reading Offset bytes
+	Struct string       // name of the struct type containing the field
+	Field  string       // the full path from root node to the field
+}
+
+func (e *UnmarshalTypeError) Error() string {
+	if e.Struct != "" || e.Field != "" {
+		return fmt.Sprintf("json: cannot unmarshal %s into Go struct field %s.%s of type %s",
+			e.Value, e.Struct, e.Field, e.Type,
+		)
+	}
+	return fmt.Sprintf("json: cannot unmarshal %s into Go value of type %s", e.Value, e.Type)
+}
+
+// An UnsupportedTypeError is returned by Marshal when attempting
+// to encode an unsupported value type.
+type UnsupportedTypeError struct {
+	Type reflect.Type
+}
+
+func (e *UnsupportedTypeError) Error() string {
+	return fmt.Sprintf("json: unsupported type: %s", e.Type)
+}
+
+type UnsupportedValueError struct {
+	Value reflect.Value
+	Str   string
+}
+
+func (e *UnsupportedValueError) Error() string {
+	return fmt.Sprintf("json: unsupported value: %s", e.Str)
+}
+
+func ErrSyntax(msg string, offset int64) *SyntaxError {
+	return &SyntaxError{msg: msg, Offset: offset}
+}
+
+func ErrMarshaler(typ reflect.Type, err error, msg string) *MarshalerError {
+	return &MarshalerError{
+		Type:       typ,
+		Err:        err,
+		sourceFunc: msg,
+	}
+}
+
+func ErrExceededMaxDepth(c byte, cursor int64) *SyntaxError {
+	return &SyntaxError{
+		msg:    fmt.Sprintf(`invalid character "%c" exceeded max depth`, c),
+		Offset: cursor,
+	}
+}
+
+func ErrNotAtBeginningOfValue(cursor int64) *SyntaxError {
+	return &SyntaxError{msg: "not at beginning of value", Offset: cursor}
+}
+
+func ErrUnexpectedEndOfJSON(msg string, cursor int64) *SyntaxError {
+	return &SyntaxError{
+		msg:    fmt.Sprintf("json: %s unexpected end of JSON input", msg),
+		Offset: cursor,
+	}
+}
+
+func ErrExpected(msg string, cursor int64) *SyntaxError {
+	return &SyntaxError{msg: fmt.Sprintf("expected %s", msg), Offset: cursor}
+}
+
+func ErrInvalidCharacter(c byte, context string, cursor int64) *SyntaxError {
+	if c == 0 {
+		return &SyntaxError{
+			msg:    fmt.Sprintf("json: invalid character as %s", context),
+			Offset: cursor,
+		}
+	}
+	return &SyntaxError{
+		msg:    fmt.Sprintf("json: invalid character %c as %s", c, context),
+		Offset: cursor,
+	}
+}
+
+func ErrInvalidBeginningOfValue(c byte, cursor int64) *SyntaxError {
+	return &SyntaxError{
+		msg:    fmt.Sprintf("invalid character '%c' looking for beginning of value", c),
+		Offset: cursor,
+	}
+}
+
+type PathError struct {
+	msg string
+}
+
+func (e *PathError) Error() string {
+	return fmt.Sprintf("json: invalid path format: %s", e.msg)
+}
+
+func ErrInvalidPath(msg string, args ...interface{}) *PathError {
+	if len(args) != 0 {
+		return &PathError{msg: fmt.Sprintf(msg, args...)}
+	}
+	return &PathError{msg: msg}
+}
+
+func ErrEmptyPath() *PathError {
+	return &PathError{msg: "path is empty"}
+}

internal/runtime/rtype.go

@@ -0,0 +1,262 @@
+package runtime
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// Type representing reflect.rtype for noescape trick
+type Type struct{}
+
+//go:linkname rtype_Align reflect.(*rtype).Align
+//go:noescape
+func rtype_Align(*Type) int
+
+func (t *Type) Align() int {
+	return rtype_Align(t)
+}
+
+//go:linkname rtype_FieldAlign reflect.(*rtype).FieldAlign
+//go:noescape
+func rtype_FieldAlign(*Type) int
+
+func (t *Type) FieldAlign() int {
+	return rtype_FieldAlign(t)
+}
+
+//go:linkname rtype_Method reflect.(*rtype).Method
+//go:noescape
+func rtype_Method(*Type, int) reflect.Method
+
+func (t *Type) Method(a0 int) reflect.Method {
+	return rtype_Method(t, a0)
+}
+
+//go:linkname rtype_MethodByName reflect.(*rtype).MethodByName
+//go:noescape
+func rtype_MethodByName(*Type, string) (reflect.Method, bool)
+
+func (t *Type) MethodByName(a0 string) (reflect.Method, bool) {
+	return rtype_MethodByName(t, a0)
+}
+
+//go:linkname rtype_NumMethod reflect.(*rtype).NumMethod
+//go:noescape
+func rtype_NumMethod(*Type) int
+
+func (t *Type) NumMethod() int {
+	return rtype_NumMethod(t)
+}
+
+//go:linkname rtype_Name reflect.(*rtype).Name
+//go:noescape
+func rtype_Name(*Type) string
+
+func (t *Type) Name() string {
+	return rtype_Name(t)
+}
+
+//go:linkname rtype_PkgPath reflect.(*rtype).PkgPath
+//go:noescape
+func rtype_PkgPath(*Type) string
+
+func (t *Type) PkgPath() string {
+	return rtype_PkgPath(t)
+}
+
+//go:linkname rtype_Size reflect.(*rtype).Size
+//go:noescape
+func rtype_Size(*Type) uintptr
+
+func (t *Type) Size() uintptr {
+	return rtype_Size(t)
+}
+
+//go:linkname rtype_String reflect.(*rtype).String
+//go:noescape
+func rtype_String(*Type) string
+
+func (t *Type) String() string {
+	return rtype_String(t)
+}
+
+//go:linkname rtype_Kind reflect.(*rtype).Kind
+//go:noescape
+func rtype_Kind(*Type) reflect.Kind
+
+func (t *Type) Kind() reflect.Kind {
+	return rtype_Kind(t)
+}
+
+//go:linkname rtype_Implements reflect.(*rtype).Implements
+//go:noescape
+func rtype_Implements(*Type, reflect.Type) bool
+
+func (t *Type) Implements(u reflect.Type) bool {
+	return rtype_Implements(t, u)
+}
+
+//go:linkname rtype_AssignableTo reflect.(*rtype).AssignableTo
+//go:noescape
+func rtype_AssignableTo(*Type, reflect.Type) bool
+
+func (t *Type) AssignableTo(u reflect.Type) bool {
+	return rtype_AssignableTo(t, u)
+}
+
+//go:linkname rtype_ConvertibleTo reflect.(*rtype).ConvertibleTo
+//go:noescape
+func rtype_ConvertibleTo(*Type, reflect.Type) bool
+
+func (t *Type) ConvertibleTo(u reflect.Type) bool {
+	return rtype_ConvertibleTo(t, u)
+}
+
+//go:linkname rtype_Comparable reflect.(*rtype).Comparable
+//go:noescape
+func rtype_Comparable(*Type) bool
+
+func (t *Type) Comparable() bool {
+	return rtype_Comparable(t)
+}
+
+//go:linkname rtype_Bits reflect.(*rtype).Bits
+//go:noescape
+func rtype_Bits(*Type) int
+
+func (t *Type) Bits() int {
+	return rtype_Bits(t)
+}
+
+//go:linkname rtype_ChanDir reflect.(*rtype).ChanDir
+//go:noescape
+func rtype_ChanDir(*Type) reflect.ChanDir
+
+func (t *Type) ChanDir() reflect.ChanDir {
+	return rtype_ChanDir(t)
+}
+
+//go:linkname rtype_IsVariadic reflect.(*rtype).IsVariadic
+//go:noescape
+func rtype_IsVariadic(*Type) bool
+
+func (t *Type) IsVariadic() bool {
+	return rtype_IsVariadic(t)
+}
+
+//go:linkname rtype_Elem reflect.(*rtype).Elem
+//go:noescape
+func rtype_Elem(*Type) reflect.Type
+
+func (t *Type) Elem() *Type {
+	return Type2RType(rtype_Elem(t))
+}
+
+//go:linkname rtype_Field reflect.(*rtype).Field
+//go:noescape
+func rtype_Field(*Type, int) reflect.StructField
+
+func (t *Type) Field(i int) reflect.StructField {
+	return rtype_Field(t, i)
+}
+
+//go:linkname rtype_FieldByIndex reflect.(*rtype).FieldByIndex
+//go:noescape
+func rtype_FieldByIndex(*Type, []int) reflect.StructField
+
+func (t *Type) FieldByIndex(index []int) reflect.StructField {
+	return rtype_FieldByIndex(t, index)
+}
+
+//go:linkname rtype_FieldByName reflect.(*rtype).FieldByName
+//go:noescape
+func rtype_FieldByName(*Type, string) (reflect.StructField, bool)
+
+func (t *Type) FieldByName(name string) (reflect.StructField, bool) {
+	return rtype_FieldByName(t, name)
+}
+
+//go:linkname rtype_FieldByNameFunc reflect.(*rtype).FieldByNameFunc
+//go:noescape
+func rtype_FieldByNameFunc(*Type, func(string) bool) (reflect.StructField, bool)
+
+func (t *Type) FieldByNameFunc(match func(string) bool) (reflect.StructField, bool) {
+	return rtype_FieldByNameFunc(t, match)
+}
+
+//go:linkname rtype_In reflect.(*rtype).In
+//go:noescape
+func rtype_In(*Type, int) reflect.Type
+
+func (t *Type) In(i int) reflect.Type {
+	return rtype_In(t, i)
+}
+
+//go:linkname rtype_Key reflect.(*rtype).Key
+//go:noescape
+func rtype_Key(*Type) reflect.Type
+
+func (t *Type) Key() *Type {
+	return Type2RType(rtype_Key(t))
+}
+
+//go:linkname rtype_Len reflect.(*rtype).Len
+//go:noescape
+func rtype_Len(*Type) int
+
+func (t *Type) Len() int {
+	return rtype_Len(t)
+}
+
+//go:linkname rtype_NumField reflect.(*rtype).NumField
+//go:noescape
+func rtype_NumField(*Type) int
+
+func (t *Type) NumField() int {
+	return rtype_NumField(t)
+}
+
+//go:linkname rtype_NumIn reflect.(*rtype).NumIn
+//go:noescape
+func rtype_NumIn(*Type) int
+
+func (t *Type) NumIn() int {
+	return rtype_NumIn(t)
+}
+
+//go:linkname rtype_NumOut reflect.(*rtype).NumOut
+//go:noescape
+func rtype_NumOut(*Type) int
+
+func (t *Type) NumOut() int {
+	return rtype_NumOut(t)
+}
+
+//go:linkname rtype_Out reflect.(*rtype).Out
+//go:noescape
+func rtype_Out(*Type, int) reflect.Type
+
+//go:linkname PtrTo reflect.(*rtype).ptrTo
+//go:noescape
+func PtrTo(*Type) *Type
+
+func (t *Type) Out(i int) reflect.Type {
+	return rtype_Out(t, i)
+}
+
+//go:linkname IfaceIndir reflect.ifaceIndir
+//go:noescape
+func IfaceIndir(*Type) bool
+
+//go:linkname RType2Type reflect.toType
+//go:noescape
+func RType2Type(t *Type) reflect.Type
+
+type emptyInterface struct {
+	_   *Type
+	ptr unsafe.Pointer
+}
+
+func Type2RType(t reflect.Type) *Type {
+	return (*Type)(((*emptyInterface)(unsafe.Pointer(&t))).ptr)
+}

internal/runtime/struct_field.go

@@ -0,0 +1,91 @@
+package runtime
+
+import (
+	"reflect"
+	"strings"
+	"unicode"
+)
+
+func getTag(field reflect.StructField) string {
+	return field.Tag.Get("json")
+}
+
+func IsIgnoredStructField(field reflect.StructField) bool {
+	if field.PkgPath != "" {
+		if field.Anonymous {
+			t := field.Type
+			if t.Kind() == reflect.Ptr {
+				t = t.Elem()
+			}
+			if t.Kind() != reflect.Struct {
+				return true
+			}
+		} else {
+			// private field
+			return true
+		}
+	}
+	tag := getTag(field)
+	return tag == "-"
+}
+
+type StructTag struct {
+	Key         string
+	IsTaggedKey bool
+	IsOmitEmpty bool
+	IsString    bool
+	Field       reflect.StructField
+}
+
+type StructTags []*StructTag
+
+func (t StructTags) ExistsKey(key string) bool {
+	for _, tt := range t {
+		if tt.Key == key {
+			return true
+		}
+	}
+	return false
+}
+
+func isValidTag(s string) bool {
+	if s == "" {
+		return false
+	}
+	for _, c := range s {
+		switch {
+		case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c):
+			// Backslash and quote chars are reserved, but
+			// otherwise any punctuation chars are allowed
+			// in a tag name.
+		case !unicode.IsLetter(c) && !unicode.IsDigit(c):
+			return false
+		}
+	}
+	return true
+}
+
+func StructTagFromField(field reflect.StructField) *StructTag {
+	keyName := field.Name
+	tag := getTag(field)
+	st := &StructTag{Field: field}
+	opts := strings.Split(tag, ",")
+	if len(opts) > 0 {
+		if opts[0] != "" && isValidTag(opts[0]) {
+			keyName = opts[0]
+			st.IsTaggedKey = true
+		}
+	}
+	st.Key = keyName
+	if len(opts) > 1 {
+		for _, opt := range opts[1:] {
+			switch opt {
+			case "omitempty":
+				st.IsOmitEmpty = true
+			case "string":
+				st.IsString = true
+			}
+		}
+	}
+	return st
+}

internal/runtime/type.go

@@ -0,0 +1,98 @@
+package runtime
+
+import (
+	"reflect"
+	"sync"
+	"unsafe"
+)
+
+type SliceHeader struct {
+	Data unsafe.Pointer
+	Len  int
+	Cap  int
+}
+
+const (
+	maxAcceptableTypeAddrRange = 1024 * 1024 * 2 // 2 Mib
+)
+
+type TypeAddr struct {
+	BaseTypeAddr uintptr
+	MaxTypeAddr  uintptr
+	AddrRange    uintptr
+	AddrShift    uintptr
+}
+
+var (
+	typeAddr *TypeAddr
+	once     sync.Once
+)
+
+//go:linkname typelinks reflect.typelinks
+func typelinks() ([]unsafe.Pointer, [][]int32)
+
+//go:linkname rtypeOff reflect.rtypeOff
+func rtypeOff(unsafe.Pointer, int32) unsafe.Pointer
+
+func AnalyzeTypeAddr() *TypeAddr {
+	once.Do(func() {
+		sections, offsets := typelinks()
+		if len(sections) != 1 {
+			return
+		}
+		if len(offsets) != 1 {
+			return
+		}
+		section := sections[0]
+		offset := offsets[0]
+		var (
+			min         uintptr = uintptr(^uint(0))
+			max         uintptr = 0
+			isAligned64         = true
+			isAligned32         = true
+		)
+		for i := 0; i < len(offset); i++ {
+			typ := (*Type)(rtypeOff(section, offset[i]))
+			addr := uintptr(unsafe.Pointer(typ))
+			if min > addr {
+				min = addr
+			}
+			if max < addr {
+				max = addr
+			}
+			if typ.Kind() == reflect.Ptr {
+				addr = uintptr(unsafe.Pointer(typ.Elem()))
+				if min > addr {
+					min = addr
+				}
+				if max < addr {
+					max = addr
+				}
+			}
+			isAligned64 = isAligned64 && (addr-min)&63 == 0
+			isAligned32 = isAligned32 && (addr-min)&31 == 0
+		}
+		addrRange := max - min
+		if addrRange == 0 {
+			return
+		}
+		var addrShift uintptr
+		if isAligned64 {
+			addrShift = 6
+		} else if isAligned32 {
+			addrShift = 5
+		}
+		cacheSize := addrRange >> addrShift
+		if cacheSize > maxAcceptableTypeAddrRange {
+			return
+		}
+		typeAddr = &TypeAddr{
+			BaseTypeAddr: min,
+			MaxTypeAddr:  max,
+			AddrRange:    addrRange,
+			AddrShift:    addrShift,
+		}
+	})
+
+	return typeAddr
+}