35da361bfa
this commit only addresses the analysis sub-package
63 lines
2.2 KiB
Go
63 lines
2.2 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 en
|
||
|
||
import (
|
||
"unicode/utf8"
|
||
|
||
"github.com/blevesearch/bleve/analysis"
|
||
"github.com/blevesearch/bleve/registry"
|
||
)
|
||
|
||
// PossessiveName is the name PossessiveFilter is registered as
|
||
// in the bleve registry.
|
||
const PossessiveName = "possessive_en"
|
||
|
||
const rightSingleQuotationMark = '’'
|
||
const apostrophe = '\''
|
||
const fullWidthApostrophe = '''
|
||
|
||
const apostropheChars = rightSingleQuotationMark + apostrophe + fullWidthApostrophe
|
||
|
||
// PossessiveFilter implements a TokenFilter which
|
||
// strips the English possessive suffix ('s) from tokens.
|
||
// It handle a variety of apostrophe types, is case-insensitive
|
||
// and doesn't distinguish between possessive and contraction.
|
||
// (ie "She's So Rad" becomes "She So Rad")
|
||
type PossessiveFilter struct {
|
||
}
|
||
|
||
func NewPossessiveFilter() *PossessiveFilter {
|
||
return &PossessiveFilter{}
|
||
}
|
||
|
||
func (s *PossessiveFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
|
||
for _, token := range input {
|
||
lastRune, lastRuneSize := utf8.DecodeLastRune(token.Term)
|
||
if lastRune == 's' || lastRune == 'S' {
|
||
nextLastRune, nextLastRuneSize := utf8.DecodeLastRune(token.Term[:len(token.Term)-lastRuneSize])
|
||
if nextLastRune == rightSingleQuotationMark ||
|
||
nextLastRune == apostrophe ||
|
||
nextLastRune == fullWidthApostrophe {
|
||
token.Term = token.Term[:len(token.Term)-lastRuneSize-nextLastRuneSize]
|
||
}
|
||
}
|
||
}
|
||
return input
|
||
}
|
||
|
||
func PossessiveFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
|
||
return NewPossessiveFilter(), nil
|
||
}
|
||
|
||
func init() {
|
||
registry.RegisterTokenFilter(PossessiveName, PossessiveFilterConstructor)
|
||
}
|