80 lines
1.9 KiB
Go
80 lines
1.9 KiB
Go
// Copyright (c) 2014 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 fa
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import (
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"bytes"
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"github.com/blevesearch/bleve/v2/analysis"
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"github.com/blevesearch/bleve/v2/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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FarsiYeh = '\u06CC'
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YehBarree = '\u06D2'
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Keheh = '\u06A9'
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Kaf = '\u0643'
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HamzaAbove = '\u0654'
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HehYeh = '\u06C0'
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HehGoal = '\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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for _, token := range input {
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term := normalize(token.Term)
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token.Term = term
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}
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return input
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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 FarsiYeh, YehBarree:
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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 HehYeh, HehGoal:
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runes[i] = Heh
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case HamzaAbove: // 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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err := registry.RegisterTokenFilter(NormalizeName, NormalizerFilterConstructor)
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if err != nil {
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panic(err)
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}
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}
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