2017-01-25 03:43:02 +01:00
|
|
|
|
// 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"
|
|
|
|
|
|
2021-01-18 02:21:14 +01:00
|
|
|
|
"github.com/blevesearch/bleve/v2/analysis"
|
|
|
|
|
"github.com/blevesearch/bleve/v2/registry"
|
2017-01-25 03:43:02 +01:00
|
|
|
|
)
|
|
|
|
|
|
|
|
|
|
// 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)
|
|
|
|
|
}
|