60 lines
1.6 KiB
Go
60 lines
1.6 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 snowball
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import (
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"fmt"
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"github.com/blevesearch/bleve/analysis"
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"github.com/blevesearch/bleve/registry"
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"github.com/kljensen/snowball"
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)
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const Name = "stemmer_snowball"
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type SnowballStemmer struct {
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langauge string
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}
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func NewSnowballStemmer(language string) *SnowballStemmer {
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return &SnowballStemmer{
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langauge: language,
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}
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}
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func (s *SnowballStemmer) Filter(input analysis.TokenStream) analysis.TokenStream {
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for _, token := range input {
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// if it is not a protected keyword, stem it
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if !token.KeyWord {
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stemmed, _ := snowball.Stem(string(token.Term), s.langauge, true)
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token.Term = []byte(stemmed)
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}
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}
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return input
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}
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func SnowballStemmerConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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language, ok := config["language"].(string)
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if !ok {
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return nil, fmt.Errorf("must specify language")
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}
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return NewSnowballStemmer(language), nil
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}
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func init() {
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registry.RegisterTokenFilter(Name, SnowballStemmerConstructor)
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}
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