yomichan/ext/bg/js/japanese.js
2020-03-28 18:17:00 -04:00

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/*
* Copyright (C) 2016-2020 Alex Yatskov <alex@foosoft.net>
* Author: Alex Yatskov <alex@foosoft.net>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/* global
* jp
* wanakana
*/
(() => {
const HALFWIDTH_KATAKANA_MAPPING = new Map([
['ヲ', 'ヲヺ-'],
['ァ', 'ァ--'],
['ィ', 'ィ--'],
['ゥ', 'ゥ--'],
['ェ', 'ェ--'],
['ォ', 'ォ--'],
['ャ', 'ャ--'],
['ュ', 'ュ--'],
['ョ', 'ョ--'],
['ッ', 'ッ--'],
['ー', 'ー--'],
['ア', 'ア--'],
['イ', 'イ--'],
['ウ', 'ウヴ-'],
['エ', 'エ--'],
['オ', 'オ--'],
['カ', 'カガ-'],
['キ', 'キギ-'],
['ク', 'クグ-'],
['ケ', 'ケゲ-'],
['コ', 'コゴ-'],
['サ', 'サザ-'],
['シ', 'シジ-'],
['ス', 'スズ-'],
['セ', 'セゼ-'],
['ソ', 'ソゾ-'],
['タ', 'タダ-'],
['チ', 'チヂ-'],
['ツ', 'ツヅ-'],
['テ', 'テデ-'],
['ト', 'トド-'],
['ナ', 'ナ--'],
['ニ', 'ニ--'],
['ヌ', 'ヌ--'],
['ネ', 'ネ--'],
['ノ', '--'],
['ハ', 'ハバパ'],
['ヒ', 'ヒビピ'],
['フ', 'フブプ'],
['ヘ', 'ヘベペ'],
['ホ', 'ホボポ'],
['マ', 'マ--'],
['ミ', 'ミ--'],
['ム', 'ム--'],
['メ', 'メ--'],
['モ', 'モ--'],
['ヤ', 'ヤ--'],
['ユ', 'ユ--'],
['ヨ', 'ヨ--'],
['ラ', 'ラ--'],
['リ', 'リ--'],
['ル', 'ル--'],
['レ', 'レ--'],
['ロ', 'ロ--'],
['ワ', 'ワ--'],
['ン', 'ン--']
]);
const ITERATION_MARK_CODE_POINT = 0x3005;
// Existing functions
const isCodePointKanji = jp.isCodePointKanji;
const isStringEntirelyKana = jp.isStringEntirelyKana;
// Conversion functions
function convertKatakanaToHiragana(text) {
let result = '';
for (const c of text) {
if (wanakana.isKatakana(c)) {
result += wanakana.toHiragana(c);
} else {
result += c;
}
}
return result;
}
function convertHiraganaToKatakana(text) {
let result = '';
for (const c of text) {
if (wanakana.isHiragana(c)) {
result += wanakana.toKatakana(c);
} else {
result += c;
}
}
return result;
}
function convertToRomaji(text) {
return wanakana.toRomaji(text);
}
function convertReading(expressionFragment, readingFragment, readingMode) {
switch (readingMode) {
case 'hiragana':
return convertKatakanaToHiragana(readingFragment || '');
case 'katakana':
return convertHiraganaToKatakana(readingFragment || '');
case 'romaji':
if (readingFragment) {
return convertToRomaji(readingFragment);
} else {
if (isStringEntirelyKana(expressionFragment)) {
return convertToRomaji(expressionFragment);
}
}
return readingFragment;
case 'none':
return null;
default:
return readingFragment;
}
}
function convertNumericToFullWidth(text) {
let result = '';
for (const char of text) {
let c = char.codePointAt(0);
if (c >= 0x30 && c <= 0x39) { // ['0', '9']
c += 0xff10 - 0x30; // 0xff10 = '0' full width
result += String.fromCodePoint(c);
} else {
result += char;
}
}
return result;
}
function convertHalfWidthKanaToFullWidth(text, sourceMap=null) {
let result = '';
// This function is safe to use charCodeAt instead of codePointAt, since all
// the relevant characters are represented with a single UTF-16 character code.
for (let i = 0, ii = text.length; i < ii; ++i) {
const c = text[i];
const mapping = HALFWIDTH_KATAKANA_MAPPING.get(c);
if (typeof mapping !== 'string') {
result += c;
continue;
}
let index = 0;
switch (text.charCodeAt(i + 1)) {
case 0xff9e: // dakuten
index = 1;
break;
case 0xff9f: // handakuten
index = 2;
break;
}
let c2 = mapping[index];
if (index > 0) {
if (c2 === '-') { // invalid
index = 0;
c2 = mapping[0];
} else {
++i;
}
}
if (sourceMap !== null && index > 0) {
sourceMap.combine(result.length, 1);
}
result += c2;
}
return result;
}
function convertAlphabeticToKana(text, sourceMap=null) {
let part = '';
let result = '';
for (const char of text) {
// Note: 0x61 is the character code for 'a'
let c = char.codePointAt(0);
if (c >= 0x41 && c <= 0x5a) { // ['A', 'Z']
c += (0x61 - 0x41);
} else if (c >= 0x61 && c <= 0x7a) { // ['a', 'z']
// NOP; c += (0x61 - 0x61);
} else if (c >= 0xff21 && c <= 0xff3a) { // ['A', 'Z'] fullwidth
c += (0x61 - 0xff21);
} else if (c >= 0xff41 && c <= 0xff5a) { // ['a', 'z'] fullwidth
c += (0x61 - 0xff41);
} else if (c === 0x2d || c === 0xff0d) { // '-' or fullwidth dash
c = 0x2d; // '-'
} else {
if (part.length > 0) {
result += convertAlphabeticPartToKana(part, sourceMap, result.length);
part = '';
}
result += char;
continue;
}
part += String.fromCodePoint(c);
}
if (part.length > 0) {
result += convertAlphabeticPartToKana(part, sourceMap, result.length);
}
return result;
}
function convertAlphabeticPartToKana(text, sourceMap, sourceMapStart) {
const result = wanakana.toHiragana(text);
// Generate source mapping
if (sourceMap !== null) {
let i = 0;
let resultPos = 0;
const ii = text.length;
while (i < ii) {
// Find smallest matching substring
let iNext = i + 1;
let resultPosNext = result.length;
while (iNext < ii) {
const t = wanakana.toHiragana(text.substring(0, iNext));
if (t === result.substring(0, t.length)) {
resultPosNext = t.length;
break;
}
++iNext;
}
// Merge characters
const removals = iNext - i - 1;
if (removals > 0) {
sourceMap.combine(sourceMapStart, removals);
}
++sourceMapStart;
// Empty elements
const additions = resultPosNext - resultPos - 1;
for (let j = 0; j < additions; ++j) {
sourceMap.insert(sourceMapStart, 0);
++sourceMapStart;
}
i = iNext;
resultPos = resultPosNext;
}
}
return result;
}
// Furigana distribution
function distributeFurigana(expression, reading) {
const fallback = [{furigana: reading, text: expression}];
if (!reading) {
return fallback;
}
let isAmbiguous = false;
const segmentize = (reading2, groups) => {
if (groups.length === 0 || isAmbiguous) {
return [];
}
const group = groups[0];
if (group.mode === 'kana') {
if (convertKatakanaToHiragana(reading2).startsWith(convertKatakanaToHiragana(group.text))) {
const readingLeft = reading2.substring(group.text.length);
const segs = segmentize(readingLeft, groups.splice(1));
if (segs) {
return [{text: group.text}].concat(segs);
}
}
} else {
let foundSegments = null;
for (let i = reading2.length; i >= group.text.length; --i) {
const readingUsed = reading2.substring(0, i);
const readingLeft = reading2.substring(i);
const segs = segmentize(readingLeft, groups.slice(1));
if (segs) {
if (foundSegments !== null) {
// more than one way to segmentize the tail, mark as ambiguous
isAmbiguous = true;
return null;
}
foundSegments = [{text: group.text, furigana: readingUsed}].concat(segs);
}
// there is only one way to segmentize the last non-kana group
if (groups.length === 1) {
break;
}
}
return foundSegments;
}
};
const groups = [];
let modePrev = null;
for (const c of expression) {
const codePoint = c.codePointAt(0);
const modeCurr = isCodePointKanji(codePoint) || codePoint === ITERATION_MARK_CODE_POINT ? 'kanji' : 'kana';
if (modeCurr === modePrev) {
groups[groups.length - 1].text += c;
} else {
groups.push({mode: modeCurr, text: c});
modePrev = modeCurr;
}
}
const segments = segmentize(reading, groups);
if (segments && !isAmbiguous) {
return segments;
}
return fallback;
}
function distributeFuriganaInflected(expression, reading, source) {
const output = [];
let stemLength = 0;
const shortest = Math.min(source.length, expression.length);
const sourceHiragana = convertKatakanaToHiragana(source);
const expressionHiragana = convertKatakanaToHiragana(expression);
while (stemLength < shortest && sourceHiragana[stemLength] === expressionHiragana[stemLength]) {
++stemLength;
}
const offset = source.length - stemLength;
const stemExpression = source.substring(0, source.length - offset);
const stemReading = reading.substring(
0,
offset === 0 ? reading.length : reading.length - expression.length + stemLength
);
for (const segment of distributeFurigana(stemExpression, stemReading)) {
output.push(segment);
}
if (stemLength !== source.length) {
output.push({text: source.substring(stemLength)});
}
return output;
}
// Exports
Object.assign(jp, {
convertKatakanaToHiragana,
convertHiraganaToKatakana,
convertToRomaji,
convertReading,
convertNumericToFullWidth,
convertHalfWidthKanaToFullWidth,
convertAlphabeticToKana,
distributeFurigana,
distributeFuriganaInflected
});
})();