52 lines
1.5 KiB
Go
52 lines
1.5 KiB
Go
// Copyright (c) 2020 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 de
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import (
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"github.com/blevesearch/bleve/v2/analysis"
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"github.com/blevesearch/bleve/v2/registry"
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"github.com/blevesearch/snowballstem"
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"github.com/blevesearch/snowballstem/german"
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)
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const SnowballStemmerName = "stemmer_de_snowball"
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type GermanStemmerFilter struct {
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}
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func NewGermanStemmerFilter() *GermanStemmerFilter {
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return &GermanStemmerFilter{}
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}
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func (s *GermanStemmerFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
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for _, token := range input {
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env := snowballstem.NewEnv(string(token.Term))
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german.Stem(env)
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token.Term = []byte(env.Current())
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}
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return input
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}
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func GermanStemmerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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return NewGermanStemmerFilter(), nil
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}
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func init() {
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err := registry.RegisterTokenFilter(SnowballStemmerName, GermanStemmerFilterConstructor)
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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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