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bleve/analysis/lang/in/scripts.go

297 lines
10 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 in
import (
"unicode"
"github.com/blevesearch/bleve/analysis"
"github.com/willf/bitset"
)
type ScriptData struct {
flag rune
base rune
decompMask *bitset.BitSet
}
var scripts = map[*unicode.RangeTable]*ScriptData{
unicode.Devanagari: {
flag: 1,
base: 0x0900,
},
unicode.Bengali: {
flag: 2,
base: 0x0980,
},
unicode.Gurmukhi: {
flag: 4,
base: 0x0A00,
},
unicode.Gujarati: {
flag: 8,
base: 0x0A80,
},
unicode.Oriya: {
flag: 16,
base: 0x0B00,
},
unicode.Tamil: {
flag: 32,
base: 0x0B80,
},
unicode.Telugu: {
flag: 64,
base: 0x0C00,
},
unicode.Kannada: {
flag: 128,
base: 0x0C80,
},
unicode.Malayalam: {
flag: 256,
base: 0x0D00,
},
}
func flag(ub *unicode.RangeTable) rune {
return scripts[ub].flag
}
var decompositions = [][]rune{
/* devanagari, gujarati vowel candra O */
{0x05, 0x3E, 0x45, 0x11, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari short O */
{0x05, 0x3E, 0x46, 0x12, flag(unicode.Devanagari)},
/* devanagari, gujarati letter O */
{0x05, 0x3E, 0x47, 0x13, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari letter AI, gujarati letter AU */
{0x05, 0x3E, 0x48, 0x14, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari, bengali, gurmukhi, gujarati, oriya AA */
{0x05, 0x3E, -1, 0x06, flag(unicode.Devanagari) | flag(unicode.Bengali) | flag(unicode.Gurmukhi) | flag(unicode.Gujarati) | flag(unicode.Oriya)},
/* devanagari letter candra A */
{0x05, 0x45, -1, 0x72, flag(unicode.Devanagari)},
/* gujarati vowel candra E */
{0x05, 0x45, -1, 0x0D, flag(unicode.Gujarati)},
/* devanagari letter short A */
{0x05, 0x46, -1, 0x04, flag(unicode.Devanagari)},
/* gujarati letter E */
{0x05, 0x47, -1, 0x0F, flag(unicode.Gujarati)},
/* gurmukhi, gujarati letter AI */
{0x05, 0x48, -1, 0x10, flag(unicode.Gurmukhi) | flag(unicode.Gujarati)},
/* devanagari, gujarati vowel candra O */
{0x05, 0x49, -1, 0x11, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari short O */
{0x05, 0x4A, -1, 0x12, flag(unicode.Devanagari)},
/* devanagari, gujarati letter O */
{0x05, 0x4B, -1, 0x13, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari letter AI, gurmukhi letter AU, gujarati letter AU */
{0x05, 0x4C, -1, 0x14, flag(unicode.Devanagari) | flag(unicode.Gurmukhi) | flag(unicode.Gujarati)},
/* devanagari, gujarati vowel candra O */
{0x06, 0x45, -1, 0x11, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari short O */
{0x06, 0x46, -1, 0x12, flag(unicode.Devanagari)},
/* devanagari, gujarati letter O */
{0x06, 0x47, -1, 0x13, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari letter AI, gujarati letter AU */
{0x06, 0x48, -1, 0x14, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* malayalam letter II */
{0x07, 0x57, -1, 0x08, flag(unicode.Malayalam)},
/* devanagari letter UU */
{0x09, 0x41, -1, 0x0A, flag(unicode.Devanagari)},
/* tamil, malayalam letter UU (some styles) */
{0x09, 0x57, -1, 0x0A, flag(unicode.Tamil) | flag(unicode.Malayalam)},
/* malayalam letter AI */
{0x0E, 0x46, -1, 0x10, flag(unicode.Malayalam)},
/* devanagari candra E */
{0x0F, 0x45, -1, 0x0D, flag(unicode.Devanagari)},
/* devanagari short E */
{0x0F, 0x46, -1, 0x0E, flag(unicode.Devanagari)},
/* devanagari AI */
{0x0F, 0x47, -1, 0x10, flag(unicode.Devanagari)},
/* oriya AI */
{0x0F, 0x57, -1, 0x10, flag(unicode.Oriya)},
/* malayalam letter OO */
{0x12, 0x3E, -1, 0x13, flag(unicode.Malayalam)},
/* telugu, kannada letter AU */
{0x12, 0x4C, -1, 0x14, flag(unicode.Telugu) | flag(unicode.Kannada)},
/* telugu letter OO */
{0x12, 0x55, -1, 0x13, flag(unicode.Telugu)},
/* tamil, malayalam letter AU */
{0x12, 0x57, -1, 0x14, flag(unicode.Tamil) | flag(unicode.Malayalam)},
/* oriya letter AU */
{0x13, 0x57, -1, 0x14, flag(unicode.Oriya)},
/* devanagari qa */
{0x15, 0x3C, -1, 0x58, flag(unicode.Devanagari)},
/* devanagari, gurmukhi khha */
{0x16, 0x3C, -1, 0x59, flag(unicode.Devanagari) | flag(unicode.Gurmukhi)},
/* devanagari, gurmukhi ghha */
{0x17, 0x3C, -1, 0x5A, flag(unicode.Devanagari) | flag(unicode.Gurmukhi)},
/* devanagari, gurmukhi za */
{0x1C, 0x3C, -1, 0x5B, flag(unicode.Devanagari) | flag(unicode.Gurmukhi)},
/* devanagari dddha, bengali, oriya rra */
{0x21, 0x3C, -1, 0x5C, flag(unicode.Devanagari) | flag(unicode.Bengali) | flag(unicode.Oriya)},
/* devanagari, bengali, oriya rha */
{0x22, 0x3C, -1, 0x5D, flag(unicode.Devanagari) | flag(unicode.Bengali) | flag(unicode.Oriya)},
/* malayalam chillu nn */
{0x23, 0x4D, 0xFF, 0x7A, flag(unicode.Malayalam)},
/* bengali khanda ta */
{0x24, 0x4D, 0xFF, 0x4E, flag(unicode.Bengali)},
/* devanagari nnna */
{0x28, 0x3C, -1, 0x29, flag(unicode.Devanagari)},
/* malayalam chillu n */
{0x28, 0x4D, 0xFF, 0x7B, flag(unicode.Malayalam)},
/* devanagari, gurmukhi fa */
{0x2B, 0x3C, -1, 0x5E, flag(unicode.Devanagari) | flag(unicode.Gurmukhi)},
/* devanagari, bengali yya */
{0x2F, 0x3C, -1, 0x5F, flag(unicode.Devanagari) | flag(unicode.Bengali)},
/* telugu letter vocalic R */
{0x2C, 0x41, 0x41, 0x0B, flag(unicode.Telugu)},
/* devanagari rra */
{0x30, 0x3C, -1, 0x31, flag(unicode.Devanagari)},
/* malayalam chillu rr */
{0x30, 0x4D, 0xFF, 0x7C, flag(unicode.Malayalam)},
/* malayalam chillu l */
{0x32, 0x4D, 0xFF, 0x7D, flag(unicode.Malayalam)},
/* devanagari llla */
{0x33, 0x3C, -1, 0x34, flag(unicode.Devanagari)},
/* malayalam chillu ll */
{0x33, 0x4D, 0xFF, 0x7E, flag(unicode.Malayalam)},
/* telugu letter MA */
{0x35, 0x41, -1, 0x2E, flag(unicode.Telugu)},
/* devanagari, gujarati vowel sign candra O */
{0x3E, 0x45, -1, 0x49, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari vowel sign short O */
{0x3E, 0x46, -1, 0x4A, flag(unicode.Devanagari)},
/* devanagari, gujarati vowel sign O */
{0x3E, 0x47, -1, 0x4B, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* devanagari, gujarati vowel sign AU */
{0x3E, 0x48, -1, 0x4C, flag(unicode.Devanagari) | flag(unicode.Gujarati)},
/* kannada vowel sign II */
{0x3F, 0x55, -1, 0x40, flag(unicode.Kannada)},
/* gurmukhi vowel sign UU (when stacking) */
{0x41, 0x41, -1, 0x42, flag(unicode.Gurmukhi)},
/* tamil, malayalam vowel sign O */
{0x46, 0x3E, -1, 0x4A, flag(unicode.Tamil) | flag(unicode.Malayalam)},
/* kannada vowel sign OO */
{0x46, 0x42, 0x55, 0x4B, flag(unicode.Kannada)},
/* kannada vowel sign O */
{0x46, 0x42, -1, 0x4A, flag(unicode.Kannada)},
/* malayalam vowel sign AI (if reordered twice) */
{0x46, 0x46, -1, 0x48, flag(unicode.Malayalam)},
/* telugu, kannada vowel sign EE */
{0x46, 0x55, -1, 0x47, flag(unicode.Telugu) | flag(unicode.Kannada)},
/* telugu, kannada vowel sign AI */
{0x46, 0x56, -1, 0x48, flag(unicode.Telugu) | flag(unicode.Kannada)},
/* tamil, malayalam vowel sign AU */
{0x46, 0x57, -1, 0x4C, flag(unicode.Tamil) | flag(unicode.Malayalam)},
/* bengali, oriya vowel sign O, tamil, malayalam vowel sign OO */
{0x47, 0x3E, -1, 0x4B, flag(unicode.Bengali) | flag(unicode.Oriya) | flag(unicode.Tamil) | flag(unicode.Malayalam)},
/* bengali, oriya vowel sign AU */
{0x47, 0x57, -1, 0x4C, flag(unicode.Bengali) | flag(unicode.Oriya)},
/* kannada vowel sign OO */
{0x4A, 0x55, -1, 0x4B, flag(unicode.Kannada)},
/* gurmukhi letter I */
{0x72, 0x3F, -1, 0x07, flag(unicode.Gurmukhi)},
/* gurmukhi letter II */
{0x72, 0x40, -1, 0x08, flag(unicode.Gurmukhi)},
/* gurmukhi letter EE */
{0x72, 0x47, -1, 0x0F, flag(unicode.Gurmukhi)},
/* gurmukhi letter U */
{0x73, 0x41, -1, 0x09, flag(unicode.Gurmukhi)},
/* gurmukhi letter UU */
{0x73, 0x42, -1, 0x0A, flag(unicode.Gurmukhi)},
/* gurmukhi letter OO */
{0x73, 0x4B, -1, 0x13, flag(unicode.Gurmukhi)},
}
func init() {
for _, scriptData := range scripts {
scriptData.decompMask = bitset.New(0x7d)
for _, decomposition := range decompositions {
ch := decomposition[0]
flags := decomposition[4]
if (flags & scriptData.flag) != 0 {
scriptData.decompMask.Set(uint(ch))
}
}
}
}
func lookupScript(r rune) *unicode.RangeTable {
for script := range scripts {
if unicode.Is(script, r) {
return script
}
}
return nil
}
func normalize(input []rune) []rune {
inputLen := len(input)
for i := 0; i < inputLen; i++ {
r := input[i]
script := lookupScript(r)
if script != nil {
scriptData := scripts[script]
ch := r - scriptData.base
if scriptData.decompMask.Test(uint(ch)) {
input = compose(ch, script, scriptData, input, i, inputLen)
inputLen = len(input)
}
}
}
return input[0:inputLen]
}
func compose(ch0 rune, script0 *unicode.RangeTable, scriptData *ScriptData, input []rune, pos int, inputLen int) []rune {
if pos+1 >= inputLen {
return input // need at least 2 characters
}
ch1 := input[pos+1] - scriptData.base
script1 := lookupScript(input[pos+1])
if script0 != script1 {
return input // need to be same script
}
ch2 := rune(-1)
if pos+2 < inputLen {
ch2 = input[pos+2] - scriptData.base
script2 := lookupScript(input[pos+2])
if input[pos+2] == '\u200D' {
ch2 = 0xff // zero width joiner
} else if script2 != script1 {
ch2 = -1 // still allow 2 character match
}
}
for _, decomposition := range decompositions {
if decomposition[0] == ch0 &&
(decomposition[4]&scriptData.flag) != 0 {
if decomposition[1] == ch1 &&
(decomposition[2] < 0 || decomposition[2] == ch2) {
input[pos] = scriptData.base + decomposition[3]
input = analysis.DeleteRune(input, pos+1)
if decomposition[2] >= 0 {
input = analysis.DeleteRune(input, pos+1)
}
return input
}
}
}
return input
}