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bleve/analysis/language/hi/hindi_normalize.go

137 lines
3.3 KiB
Go

// Copyright (c) 2014 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 hi
import (
"bytes"
"github.com/couchbaselabs/bleve/analysis"
"github.com/couchbaselabs/bleve/registry"
)
const NormalizeName = "normalize_hi"
type HindiNormalizeFilter struct {
}
func NewHindiNormalizeFilter() *HindiNormalizeFilter {
return &HindiNormalizeFilter{}
}
func (s *HindiNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
rv := make(analysis.TokenStream, 0)
for _, token := range input {
term := normalize(token.Term)
token.Term = term
rv = append(rv, token)
}
return rv
}
func normalize(input []byte) []byte {
runes := bytes.Runes(input)
for i := 0; i < len(runes); i++ {
switch runes[i] {
// dead n -> bindu
case '\u0928':
if i+1 < len(runes) && runes[i+1] == '\u094D' {
runes[i] = '\u0902'
runes = analysis.DeleteRune(runes, i+1)
}
// candrabindu -> bindu
case '\u0901':
runes[i] = '\u0902'
// nukta deletions
case '\u093C':
runes = analysis.DeleteRune(runes, i)
i--
case '\u0929':
runes[i] = '\u0928'
case '\u0931':
runes[i] = '\u0930'
case '\u0934':
runes[i] = '\u0933'
case '\u0958':
runes[i] = '\u0915'
case '\u0959':
runes[i] = '\u0916'
case '\u095A':
runes[i] = '\u0917'
case '\u095B':
runes[i] = '\u091C'
case '\u095C':
runes[i] = '\u0921'
case '\u095D':
runes[i] = '\u0922'
case '\u095E':
runes[i] = '\u092B'
case '\u095F':
runes[i] = '\u092F'
// zwj/zwnj -> delete
case '\u200D', '\u200C':
runes = analysis.DeleteRune(runes, i)
i--
// virama -> delete
case '\u094D':
runes = analysis.DeleteRune(runes, i)
i--
// chandra/short -> replace
case '\u0945', '\u0946':
runes[i] = '\u0947'
case '\u0949', '\u094A':
runes[i] = '\u094B'
case '\u090D', '\u090E':
runes[i] = '\u090F'
case '\u0911', '\u0912':
runes[i] = '\u0913'
case '\u0972':
runes[i] = '\u0905'
// long -> short ind. vowels
case '\u0906':
runes[i] = '\u0905'
case '\u0908':
runes[i] = '\u0907'
case '\u090A':
runes[i] = '\u0909'
case '\u0960':
runes[i] = '\u090B'
case '\u0961':
runes[i] = '\u090C'
case '\u0910':
runes[i] = '\u090F'
case '\u0914':
runes[i] = '\u0913'
// long -> short dep. vowels
case '\u0940':
runes[i] = '\u093F'
case '\u0942':
runes[i] = '\u0941'
case '\u0944':
runes[i] = '\u0943'
case '\u0963':
runes[i] = '\u0962'
case '\u0948':
runes[i] = '\u0947'
case '\u094C':
runes[i] = '\u094B'
}
}
return analysis.BuildTermFromRunes(runes)
}
func NormalizerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
return NewHindiNormalizeFilter(), nil
}
func init() {
registry.RegisterTokenFilter(NormalizeName, NormalizerFilterConstructor)
}