80 lines
2.0 KiB
Go
80 lines
2.0 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 unicodenorm
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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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"golang.org/x/text/unicode/norm"
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)
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const Name = "normalize_unicode"
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const NFC = "nfc"
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const NFD = "nfd"
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const NFKC = "nfkc"
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const NFKD = "nfkd"
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var forms = map[string]norm.Form{
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NFC: norm.NFC,
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NFD: norm.NFD,
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NFKC: norm.NFKC,
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NFKD: norm.NFKD,
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}
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type UnicodeNormalizeFilter struct {
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form norm.Form
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}
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func NewUnicodeNormalizeFilter(formName string) (*UnicodeNormalizeFilter, error) {
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form, ok := forms[formName]
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if !ok {
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return nil, fmt.Errorf("no form named %s", formName)
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}
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return &UnicodeNormalizeFilter{
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form: form,
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}, nil
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}
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func MustNewUnicodeNormalizeFilter(formName string) *UnicodeNormalizeFilter {
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filter, err := NewUnicodeNormalizeFilter(formName)
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if err != nil {
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panic(err)
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}
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return filter
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}
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func (s *UnicodeNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
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for _, token := range input {
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token.Term = s.form.Bytes(token.Term)
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}
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return input
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}
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func UnicodeNormalizeFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
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formVal, ok := config["form"].(string)
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if !ok {
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return nil, fmt.Errorf("must specify form")
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}
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form := formVal
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return NewUnicodeNormalizeFilter(form)
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}
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func init() {
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registry.RegisterTokenFilter(Name, UnicodeNormalizeFilterConstructor)
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}
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