Move japanese.js into bg

1 files changed, 454 insertions, 0 deletions

diff --git a/ext/bg/js/japanese.js b/ext/bg/js/japanese.js
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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/>.
+ */
+
+
+const JP_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', '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 JP_HIRAGANA_RANGE = [0x3040, 0x309f];
+const JP_KATAKANA_RANGE = [0x30a0, 0x30ff];
+const JP_KANA_RANGES = [JP_HIRAGANA_RANGE, JP_KATAKANA_RANGE];
+
+const JP_CJK_COMMON_RANGE = [0x4e00, 0x9fff];
+const JP_CJK_RARE_RANGE = [0x3400, 0x4dbf];
+const JP_CJK_RANGES = [JP_CJK_COMMON_RANGE, JP_CJK_RARE_RANGE];
+
+const JP_ITERATION_MARK_CHAR_CODE = 0x3005;
+
+// Japanese character ranges, roughly ordered in order of expected frequency
+const JP_JAPANESE_RANGES = [
+    JP_HIRAGANA_RANGE,
+    JP_KATAKANA_RANGE,
+
+    JP_CJK_COMMON_RANGE,
+    JP_CJK_RARE_RANGE,
+
+    [0xff66, 0xff9f], // Halfwidth katakana
+
+    [0x30fb, 0x30fc], // Katakana punctuation
+    [0xff61, 0xff65], // Kana punctuation
+    [0x3000, 0x303f], // CJK punctuation
+
+    [0xff10, 0xff19], // Fullwidth numbers
+    [0xff21, 0xff3a], // Fullwidth upper case Latin letters
+    [0xff41, 0xff5a], // Fullwidth lower case Latin letters
+
+    [0xff01, 0xff0f], // Fullwidth punctuation 1
+    [0xff1a, 0xff1f], // Fullwidth punctuation 2
+    [0xff3b, 0xff3f], // Fullwidth punctuation 3
+    [0xff5b, 0xff60], // Fullwidth punctuation 4
+    [0xffe0, 0xffee], // Currency markers
+];
+
+
+// Helper functions
+
+function _jpIsCharCodeInRanges(charCode, ranges) {
+    for (const [min, max] of ranges) {
+        if (charCode >= min && charCode <= max) {
+            return true;
+        }
+    }
+    return false;
+}
+
+
+// Character code testing functions
+
+function jpIsCharCodeKanji(charCode) {
+    return _jpIsCharCodeInRanges(charCode, JP_CJK_RANGES);
+}
+
+function jpIsCharCodeKana(charCode) {
+    return _jpIsCharCodeInRanges(charCode, JP_KANA_RANGES);
+}
+
+function jpIsCharCodeJapanese(charCode) {
+    return _jpIsCharCodeInRanges(charCode, JP_JAPANESE_RANGES);
+}
+
+
+// String testing functions
+
+function jpIsStringEntirelyKana(str) {
+    if (str.length === 0) { return false; }
+    for (let i = 0, ii = str.length; i < ii; ++i) {
+        if (!jpIsCharCodeKana(str.charCodeAt(i))) {
+            return false;
+        }
+    }
+    return true;
+}
+
+function jpIsStringPartiallyJapanese(str) {
+    if (str.length === 0) { return false; }
+    for (let i = 0, ii = str.length; i < ii; ++i) {
+        if (jpIsCharCodeJapanese(str.charCodeAt(i))) {
+            return true;
+        }
+    }
+    return false;
+}
+
+
+// Conversion functions
+
+function jpKatakanaToHiragana(text) {
+    let result = '';
+    for (const c of text) {
+        if (wanakana.isKatakana(c)) {
+            result += wanakana.toHiragana(c);
+        } else {
+            result += c;
+        }
+    }
+
+    return result;
+}
+
+function jpHiraganaToKatakana(text) {
+    let result = '';
+    for (const c of text) {
+        if (wanakana.isHiragana(c)) {
+            result += wanakana.toKatakana(c);
+        } else {
+            result += c;
+        }
+    }
+
+    return result;
+}
+
+function jpToRomaji(text) {
+    return wanakana.toRomaji(text);
+}
+
+function jpConvertReading(expressionFragment, readingFragment, readingMode) {
+    switch (readingMode) {
+        case 'hiragana':
+            return jpKatakanaToHiragana(readingFragment || '');
+        case 'katakana':
+            return jpHiraganaToKatakana(readingFragment || '');
+        case 'romaji':
+            if (readingFragment) {
+                return jpToRomaji(readingFragment);
+            } else {
+                if (jpIsStringEntirelyKana(expressionFragment)) {
+                    return jpToRomaji(expressionFragment);
+                }
+            }
+            return readingFragment;
+        case 'none':
+            return null;
+        default:
+            return readingFragment;
+    }
+}
+
+function jpDistributeFurigana(expression, reading) {
+    const fallback = [{furigana: reading, text: expression}];
+    if (!reading) {
+        return fallback;
+    }
+
+    let isAmbiguous = false;
+    const segmentize = (reading, groups) => {
+        if (groups.length === 0 || isAmbiguous) {
+            return [];
+        }
+
+        const group = groups[0];
+        if (group.mode === 'kana') {
+            if (jpKatakanaToHiragana(reading).startsWith(jpKatakanaToHiragana(group.text))) {
+                const readingLeft = reading.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 = reading.length; i >= group.text.length; --i) {
+                const readingUsed = reading.substring(0, i);
+                const readingLeft = reading.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 charCode = c.charCodeAt(0);
+        const modeCurr = jpIsCharCodeKanji(charCode) || charCode === JP_ITERATION_MARK_CHAR_CODE ? '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 jpDistributeFuriganaInflected(expression, reading, source) {
+    const output = [];
+
+    let stemLength = 0;
+    const shortest = Math.min(source.length, expression.length);
+    const sourceHiragana = jpKatakanaToHiragana(source);
+    const expressionHiragana = jpKatakanaToHiragana(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 jpDistributeFurigana(stemExpression, stemReading)) {
+        output.push(segment);
+    }
+
+    if (stemLength !== source.length) {
+        output.push({text: source.substring(stemLength)});
+    }
+
+    return output;
+}
+
+function jpConvertHalfWidthKanaToFullWidth(text, sourceMapping) {
+    let result = '';
+    const ii = text.length;
+    const hasSourceMapping = Array.isArray(sourceMapping);
+
+    for (let i = 0; i < ii; ++i) {
+        const c = text[i];
+        const mapping = JP_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 (hasSourceMapping && index > 0) {
+            index = result.length;
+            const v = sourceMapping.splice(index + 1, 1)[0];
+            sourceMapping[index] += v;
+        }
+        result += c2;
+    }
+
+    return result;
+}
+
+function jpConvertNumericTofullWidth(text) {
+    let result = '';
+    for (let i = 0, ii = text.length; i < ii; ++i) {
+        let c = text.charCodeAt(i);
+        if (c >= 0x30 && c <= 0x39) { // ['0', '9']
+            c += 0xff10 - 0x30; // 0xff10 = '0' full width
+            result += String.fromCharCode(c);
+        } else {
+            result += text[i];
+        }
+    }
+    return result;
+}
+
+function jpConvertAlphabeticToKana(text, sourceMapping) {
+    let part = '';
+    let result = '';
+    const ii = text.length;
+
+    if (sourceMapping.length === ii) {
+        sourceMapping.length = ii;
+        sourceMapping.fill(1);
+    }
+
+    for (let i = 0; i < ii; ++i) {
+        // Note: 0x61 is the character code for 'a'
+        let c = text.charCodeAt(i);
+        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 += jpToHiragana(part, sourceMapping, result.length);
+                part = '';
+            }
+            result += text[i];
+            continue;
+        }
+        part += String.fromCharCode(c);
+    }
+
+    if (part.length > 0) {
+        result += jpToHiragana(part, sourceMapping, result.length);
+    }
+    return result;
+}
+
+function jpToHiragana(text, sourceMapping, sourceMappingStart) {
+    const result = wanakana.toHiragana(text);
+
+    // Generate source mapping
+    if (Array.isArray(sourceMapping)) {
+        if (typeof sourceMappingStart !== 'number') { sourceMappingStart = 0; }
+        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) {
+                let sum = 0;
+                const vs = sourceMapping.splice(sourceMappingStart + 1, removals);
+                for (const v of vs) { sum += v; }
+                sourceMapping[sourceMappingStart] += sum;
+            }
+            ++sourceMappingStart;
+
+            // Empty elements
+            const additions = resultPosNext - resultPos - 1;
+            for (let j = 0; j < additions; ++j) {
+                sourceMapping.splice(sourceMappingStart, 0, 0);
+                ++sourceMappingStart;
+            }
+
+            i = iNext;
+            resultPos = resultPosNext;
+        }
+    }
+
+    return result;
+}