c526a38369
ultimately this is make it more convenient for us to wire up different elements of the analysis pipeline, without having to preload everything into memory before we need it separately the index layer now has a mechanism for storing internal key/value pairs. this is expected to be used to store the mapping, and possibly other pieces of data by the top layer, but not exposed to the user at the top.
74 lines
1.9 KiB
Go
74 lines
1.9 KiB
Go
// Copyright (c) 2014 Couchbase, Inc.
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
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// except in compliance with the License. You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed under the
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// License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
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// either express or implied. See the License for the specific language governing permissions
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// and limitations under the License.
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package stemmer_filter
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import (
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"bitbucket.org/tebeka/snowball"
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"github.com/couchbaselabs/bleve/analysis"
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"github.com/couchbaselabs/bleve/registry"
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)
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const Name = "stem"
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type StemmerFilter struct {
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lang string
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stemmer *snowball.Stemmer
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}
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func NewStemmerFilter(lang string) (*StemmerFilter, error) {
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stemmer, err := snowball.New(lang)
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if err != nil {
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return nil, err
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}
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return &StemmerFilter{
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lang: lang,
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stemmer: stemmer,
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}, nil
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}
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func MustNewStemmerFilter(lang string) *StemmerFilter {
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sf, err := NewStemmerFilter(lang)
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if err != nil {
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panic(err)
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}
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return sf
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}
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func (s *StemmerFilter) List() []string {
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return snowball.LangList()
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}
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func (s *StemmerFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
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rv := make(analysis.TokenStream, 0)
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for _, token := range input {
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// if not protected keyword, stem it
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if !token.KeyWord {
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stemmed := s.stemmer.Stem(string(token.Term))
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token.Term = []byte(stemmed)
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}
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rv = append(rv, token)
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}
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return rv
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}
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func StemmerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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lang := "en"
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langVal, ok := config["lang"].(string)
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if ok {
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lang = langVal
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}
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return NewStemmerFilter(lang)
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}
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func init() {
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registry.RegisterTokenFilter(Name, StemmerFilterConstructor)
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}
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