Adding upstream version 2.5.1.

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

analysis/token/camelcase/camelcase.go

@@ -0,0 +1,81 @@
+//  Copyright (c) 2016 Couchbase, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 		http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package camelcase
+
+import (
+	"bytes"
+	"unicode/utf8"
+
+	"github.com/blevesearch/bleve/v2/analysis"
+	"github.com/blevesearch/bleve/v2/registry"
+)
+
+const Name = "camelCase"
+
+// CamelCaseFilter splits a given token into a set of tokens where each resulting token
+// falls into one the following classes:
+//  1. Upper case followed by lower case letters.
+//     Terminated by a number, an upper case letter, and a non alpha-numeric symbol.
+//  2. Upper case followed by upper case letters.
+//     Terminated by a number, an upper case followed by a lower case letter, and a non alpha-numeric symbol.
+//  3. Lower case followed by lower case letters.
+//     Terminated by a number, an upper case letter, and a non alpha-numeric symbol.
+//  4. Number followed by numbers.
+//     Terminated by a letter, and a non alpha-numeric symbol.
+//  5. Non alpha-numeric symbol followed by non alpha-numeric symbols.
+//     Terminated by a number, and a letter.
+//
+// It does a one-time sequential pass over an input token, from left to right.
+// The scan is greedy and generates the longest substring that fits into one of the classes.
+//
+// See the test file for examples of classes and their parsings.
+type CamelCaseFilter struct{}
+
+func NewCamelCaseFilter() *CamelCaseFilter {
+	return &CamelCaseFilter{}
+}
+
+func (f *CamelCaseFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
+	rv := make(analysis.TokenStream, 0, len(input))
+
+	nextPosition := 1
+	for _, token := range input {
+		runeCount := utf8.RuneCount(token.Term)
+		runes := bytes.Runes(token.Term)
+
+		p := NewParser(runeCount, nextPosition, token.Start)
+		for i := 0; i < runeCount; i++ {
+			if i+1 >= runeCount {
+				p.Push(runes[i], nil)
+			} else {
+				p.Push(runes[i], &runes[i+1])
+			}
+		}
+		rv = append(rv, p.FlushTokens()...)
+		nextPosition = p.NextPosition()
+	}
+	return rv
+}
+
+func CamelCaseFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
+	return NewCamelCaseFilter(), nil
+}
+
+func init() {
+	err := registry.RegisterTokenFilter(Name, CamelCaseFilterConstructor)
+	if err != nil {
+		panic(err)
+	}
+}