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bleve/analysis/tokenizers/character/character.go
Marty Schoch 0b171c85da change "simple" analyzer to use "letter" tokenizer
this change improves compatibility with the simple analyzer
defined by Lucene.  this has important implications for
some perf tests as well as they often use the simple
analyzer.
2016-03-31 15:13:17 -04:00

72 lines
1.8 KiB
Go

// 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 character
import (
"unicode/utf8"
"github.com/blevesearch/bleve/analysis"
)
type IsTokenRune func(r rune) bool
type CharacterTokenizer struct {
isTokenRun IsTokenRune
}
func NewCharacterTokenizer(f IsTokenRune) *CharacterTokenizer {
return &CharacterTokenizer{
isTokenRun: f,
}
}
func (c *CharacterTokenizer) Tokenize(input []byte) analysis.TokenStream {
rv := make(analysis.TokenStream, 0, 1024)
offset := 0
start := 0
end := 0
count := 0
for currRune, size := utf8.DecodeRune(input[offset:]); currRune != utf8.RuneError; currRune, size = utf8.DecodeRune(input[offset:]) {
isToken := c.isTokenRun(currRune)
if isToken {
end = offset + size
} else {
if end-start > 0 {
// build token
rv = append(rv, &analysis.Token{
Term: input[start:end],
Start: start,
End: end,
Position: count + 1,
Type: analysis.AlphaNumeric,
})
count++
}
start = offset + size
end = start
}
offset += size
}
// if we ended in the middle of a token, finish it
if end-start > 0 {
// build token
rv = append(rv, &analysis.Token{
Term: input[start:end],
Start: start,
End: end,
Position: count + 1,
Type: analysis.AlphaNumeric,
})
}
return rv
}