// 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 ckb import ( "bytes" "unicode" "github.com/couchbaselabs/bleve/analysis" "github.com/couchbaselabs/bleve/registry" ) const NormalizeName = "normalize_ckb" const ( YEH = '\u064A' DOTLESS_YEH = '\u0649' FARSI_YEH = '\u06CC' KAF = '\u0643' KEHEH = '\u06A9' HEH = '\u0647' AE = '\u06D5' ZWNJ = '\u200C' HEH_DOACHASHMEE = '\u06BE' TEH_MARBUTA = '\u0629' REH = '\u0631' RREH = '\u0695' RREH_ABOVE = '\u0692' TATWEEL = '\u0640' FATHATAN = '\u064B' DAMMATAN = '\u064C' KASRATAN = '\u064D' FATHA = '\u064E' DAMMA = '\u064F' KASRA = '\u0650' SHADDA = '\u0651' SUKUN = '\u0652' ) type SoraniNormalizeFilter struct { } func NewSoraniNormalizeFilter() *SoraniNormalizeFilter { return &SoraniNormalizeFilter{} } func (s *SoraniNormalizeFilter) Filter(input analysis.TokenStream) analysis.TokenStream { rv := make(analysis.TokenStream, 0) for _, token := range input { term := normalize(token.Term) token.Term = term rv = append(rv, token) } return rv } func normalize(input []byte) []byte { runes := bytes.Runes(input) for i := 0; i < len(runes); i++ { switch runes[i] { case YEH, DOTLESS_YEH: runes[i] = FARSI_YEH case KAF: runes[i] = KEHEH case ZWNJ: if i > 0 && runes[i-1] == HEH { runes[i-1] = AE } runes = analysis.DeleteRune(runes, i) i-- case HEH: if i == len(runes)-1 { runes[i] = AE } case TEH_MARBUTA: runes[i] = AE case HEH_DOACHASHMEE: runes[i] = HEH case REH: if i == 0 { runes[i] = RREH } case RREH_ABOVE: runes[i] = RREH case TATWEEL, KASRATAN, DAMMATAN, FATHATAN, FATHA, DAMMA, KASRA, SHADDA, SUKUN: runes = analysis.DeleteRune(runes, i) i-- default: if unicode.In(runes[i], unicode.Cf) { runes = analysis.DeleteRune(runes, i) i-- } } } return analysis.BuildTermFromRunes(runes) } func NormalizerFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) { return NewSoraniNormalizeFilter(), nil } func init() { registry.RegisterTokenFilter(NormalizeName, NormalizerFilterConstructor) }