102 lines
3.1 KiB
Go
102 lines
3.1 KiB
Go
// Copyright (c) 2016 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 cjk
|
|
|
|
import (
|
|
"bytes"
|
|
"unicode/utf8"
|
|
|
|
"github.com/blevesearch/bleve/analysis"
|
|
"github.com/blevesearch/bleve/registry"
|
|
)
|
|
|
|
const WidthName = "cjk_width"
|
|
|
|
type CJKWidthFilter struct{}
|
|
|
|
func NewCJKWidthFilter() *CJKWidthFilter {
|
|
return &CJKWidthFilter{}
|
|
}
|
|
|
|
func (s *CJKWidthFilter) Filter(input analysis.TokenStream) analysis.TokenStream {
|
|
for _, token := range input {
|
|
runeCount := utf8.RuneCount(token.Term)
|
|
runes := bytes.Runes(token.Term)
|
|
for i := 0; i < runeCount; i++ {
|
|
ch := runes[i]
|
|
if ch >= 0xFF01 && ch <= 0xFF5E {
|
|
// fullwidth ASCII variants
|
|
runes[i] -= 0xFEE0
|
|
} else if ch >= 0xFF65 && ch <= 0xFF9F {
|
|
// halfwidth Katakana variants
|
|
if (ch == 0xFF9E || ch == 0xFF9F) && i > 0 && combine(runes, i, ch) {
|
|
runes = analysis.DeleteRune(runes, i)
|
|
i--
|
|
runeCount = len(runes)
|
|
} else {
|
|
runes[i] = kanaNorm[ch-0xFF65]
|
|
}
|
|
}
|
|
}
|
|
token.Term = analysis.BuildTermFromRunes(runes)
|
|
}
|
|
|
|
return input
|
|
}
|
|
|
|
var kanaNorm = []rune{
|
|
0x30fb, 0x30f2, 0x30a1, 0x30a3, 0x30a5, 0x30a7, 0x30a9, 0x30e3, 0x30e5,
|
|
0x30e7, 0x30c3, 0x30fc, 0x30a2, 0x30a4, 0x30a6, 0x30a8, 0x30aa, 0x30ab,
|
|
0x30ad, 0x30af, 0x30b1, 0x30b3, 0x30b5, 0x30b7, 0x30b9, 0x30bb, 0x30bd,
|
|
0x30bf, 0x30c1, 0x30c4, 0x30c6, 0x30c8, 0x30ca, 0x30cb, 0x30cc, 0x30cd,
|
|
0x30ce, 0x30cf, 0x30d2, 0x30d5, 0x30d8, 0x30db, 0x30de, 0x30df, 0x30e0,
|
|
0x30e1, 0x30e2, 0x30e4, 0x30e6, 0x30e8, 0x30e9, 0x30ea, 0x30eb, 0x30ec,
|
|
0x30ed, 0x30ef, 0x30f3, 0x3099, 0x309A,
|
|
}
|
|
|
|
var kanaCombineVoiced = []rune{
|
|
78, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
|
|
0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1,
|
|
0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 8, 8, 8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
|
|
}
|
|
var kanaCombineHalfVoiced = []rune{
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 2,
|
|
0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
}
|
|
|
|
func combine(text []rune, pos int, r rune) bool {
|
|
prev := text[pos-1]
|
|
if prev >= 0x30A6 && prev <= 0x30FD {
|
|
if r == 0xFF9F {
|
|
text[pos-1] += kanaCombineHalfVoiced[prev-0x30A6]
|
|
} else {
|
|
text[pos-1] += kanaCombineVoiced[prev-0x30A6]
|
|
}
|
|
return text[pos-1] != prev
|
|
}
|
|
return false
|
|
}
|
|
|
|
func CJKWidthFilterConstructor(config map[string]interface{}, cache *registry.Cache) (analysis.TokenFilter, error) {
|
|
return NewCJKWidthFilter(), nil
|
|
}
|
|
|
|
func init() {
|
|
registry.RegisterTokenFilter(WidthName, CJKWidthFilterConstructor)
|
|
}
|