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76 lines
1.8 KiB
76 lines
1.8 KiB
// Copyright (c) 2016 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package character
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import (
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"unicode/utf8"
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"github.com/blevesearch/bleve/analysis"
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)
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type IsTokenRune func(r rune) bool
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type CharacterTokenizer struct {
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isTokenRun IsTokenRune
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}
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func NewCharacterTokenizer(f IsTokenRune) *CharacterTokenizer {
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return &CharacterTokenizer{
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isTokenRun: f,
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}
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}
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func (c *CharacterTokenizer) Tokenize(input []byte) analysis.TokenStream {
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rv := make(analysis.TokenStream, 0, 1024)
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offset := 0
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start := 0
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end := 0
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count := 0
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for currRune, size := utf8.DecodeRune(input[offset:]); currRune != utf8.RuneError; currRune, size = utf8.DecodeRune(input[offset:]) {
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isToken := c.isTokenRun(currRune)
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if isToken {
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end = offset + size
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} else {
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if end-start > 0 {
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// build token
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rv = append(rv, &analysis.Token{
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Term: input[start:end],
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Start: start,
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End: end,
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Position: count + 1,
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Type: analysis.AlphaNumeric,
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})
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count++
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}
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start = offset + size
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end = start
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}
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offset += size
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}
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// if we ended in the middle of a token, finish it
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if end-start > 0 {
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// build token
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rv = append(rv, &analysis.Token{
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Term: input[start:end],
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Start: start,
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End: end,
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Position: count + 1,
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Type: analysis.AlphaNumeric,
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})
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}
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return rv
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}
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