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bleve/analysis/lang/fr/minimal_stemmer_fr.go

80 lines
2.0 KiB
Go

// Copyright (c) 2015 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 fr
import (
"bytes"
"github.com/blevesearch/bleve/analysis"
"github.com/blevesearch/bleve/registry"
)
const MinimalStemmerName = "stemmer_fr_min"
type FrenchMinimalStemmerFilter struct {
}
func NewFrenchMinimalStemmerFilter() *FrenchMinimalStemmerFilter {
return &FrenchMinimalStemmerFilter{}
}
func (s *FrenchMinimalStemmerFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
for _, token := range input {
runes := bytes.Runes(token.Term)
runes = minstem(runes)
token.Term = analysis.BuildTermFromRunes(runes)
}
return input
}
func minstem(input []rune) []rune {
if len(input) < 6 {
return input
}
if input[len(input)-1] == 'x' {
if input[len(input)-3] == 'a' && input[len(input)-2] == 'u' {
input[len(input)-2] = 'l'
}
return input[0 : len(input)-1]
}
if input[len(input)-1] == 's' {
input = input[0 : len(input)-1]
}
if input[len(input)-1] == 'r' {
input = input[0 : len(input)-1]
}
if input[len(input)-1] == 'e' {
input = input[0 : len(input)-1]
}
if input[len(input)-1] == 'é' {
input = input[0 : len(input)-1]
}
if input[len(input)-1] == input[len(input)-2] {
input = input[0 : len(input)-1]
}
return input
}
func FrenchMinimalStemmerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
return NewFrenchMinimalStemmerFilter(), nil
}
func init() {
registry.RegisterTokenFilter(MinimalStemmerName, FrenchMinimalStemmerFilterConstructor)
}