76 lines
2.0 KiB
Go
76 lines
2.0 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
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// except in compliance with the License. You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed under the
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// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
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// either express or implied. See the License for the specific language governing permissions
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// and limitations under the License.
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package fa
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import (
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"bytes"
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"github.com/couchbaselabs/bleve/analysis"
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"github.com/couchbaselabs/bleve/registry"
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)
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const NormalizeName = "normalize_fa"
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const (
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YEH = '\u064A'
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FARSI_YEH = '\u06CC'
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YEH_BARREE = '\u06D2'
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KEHEH = '\u06A9'
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KAF = '\u0643'
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HAMZA_ABOVE = '\u0654'
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HEH_YEH = '\u06C0'
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HEH_GOAL = '\u06C1'
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HEH = '\u0647'
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)
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type PersianNormalizeFilter struct {
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}
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func NewPersianNormalizeFilter() *PersianNormalizeFilter {
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return &PersianNormalizeFilter{}
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}
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func (s *PersianNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
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rv := make(analysis.TokenStream, 0)
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for _, token := range input {
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term := normalize(token.Term)
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token.Term = term
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rv = append(rv, token)
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}
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return rv
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}
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func normalize(input []byte) []byte {
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runes := bytes.Runes(input)
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for i := 0; i < len(runes); i++ {
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switch runes[i] {
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case FARSI_YEH, YEH_BARREE:
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runes[i] = YEH
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case KEHEH:
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runes[i] = KAF
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case HEH_YEH, HEH_GOAL:
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runes[i] = HEH
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case HAMZA_ABOVE: // necessary for HEH + HAMZA
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runes = analysis.DeleteRune(runes, i)
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i--
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}
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}
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return analysis.BuildTermFromRunes(runes)
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}
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func NormalizerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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return NewPersianNormalizeFilter(), nil
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}
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func init() {
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registry.RegisterTokenFilter(NormalizeName, NormalizerFilterConstructor)
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}
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