Adding upstream version 0.10.5.

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

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
+}