Yosina JavaScript

A TypeScript port of the Yosina Japanese text transliteration library.

Overview

Yosina is a library for Japanese text transliteration that provides various text normalization and conversion features commonly needed when processing Japanese text.

Usage

import { makeTransliterator, TransliterationRecipe } from '@yosina-lib/yosina';

// Create a recipe with desired transformations
const recipe: TransliterationRecipe = {
  kanjiOldNew: true,
  replaceSpaces: true,
  replaceSuspiciousHyphensToProlongedSoundMarks: true,
  replaceCircledOrSquaredCharacters: true,
  replaceCombinedCharacters: true,
  hiraKata: "hira-to-kata", // Convert hiragana to katakana
  replaceJapaneseIterationMarks: true, // Expand iteration marks
  toFullwidth: true,
};

// Create the transliterator
const transliterator = await makeTransliterator(recipe);

// Use it with various special characters
const input = '①②③　ⒶⒷⒸ　㍿㍑㌠㋿'; // circled numbers, letters, space, combined characters
const result = transliterator(input);
console.log(result); // "(1)(2)(3) (A)(B)(C) 株式会社リットルサンチーム令和"

// Convert old kanji to new
const oldKanji = '舊字體';
const kanjiResult = transliterator(oldKanji);
console.log(kanjiResult); // "旧字体"

// Convert half-width katakana to full-width
const halfWidth = 'ﾃｽﾄﾓｼﾞﾚﾂ';
const fullWidthResult = transliterator(halfWidth);
console.log(fullWidthResult); // "テストモジレツ"

// Demonstrate hiragana to katakana conversion with iteration marks
const mixedText = '学問のすゝめ';
const convertedResult = transliterator(mixedText);
console.log(convertedResult); // "学問ノススメ"

Using Direct Configuration

import { makeTransliterator } from '@yosina-lib/yosina';

// Configure with direct transliterator configs
const configs = [
  ["kanji-old-new", {}],
  ["spaces", {}],
  ["prolonged-sound-marks", { replaceProlongedMarksFollowingAlnums: true }],
  ["circled-or-squared", {}],
  ["combined", {}],
  ["hira-kata", { mode: "kata-to-hira" }], // Convert katakana to hiragana
  ["japanese-iteration-marks", {}], // Expand iteration marks like 々, ゝゞ, ヽヾ
];

const transliterator = await makeTransliterator(configs);

// Example with various transformations including the new ones
const input = "カタカナでの時々の佐々木さん";
const result = transliterator(input);
console.log(result); // "かたかなでの時時の佐佐木さん"

Available Transliterators

1. Circled or Squared (circled-or-squared)

Converts circled or squared characters to their plain equivalents.

• Options: templates (custom rendering), includeEmojis (include emoji characters)
• Example: ①②③ → (1)(2)(3), ㊙㊗ → (秘)(祝)

2. Combined (combined)

Expands combined characters into their individual character sequences.

• Example: ㍻ (Heisei era) → 平成, ㈱ → (株)

3. Hiragana-Katakana Composition (hira-kata-composition)

Combines decomposed hiraganas and katakanas into composed equivalents.

• Options: composeNonCombiningMarks (compose non-combining marks)
• Example: か + ゙ → が, ヘ + ゜ → ペ

4. Hiragana-Katakana (hira-kata)

Converts between hiragana and katakana scripts bidirectionally.

• Options: mode ("hira-to-kata" or "kata-to-hira")
• Example: ひらがな → ヒラガナ (hira-to-kata)

5. Hyphens (hyphens)

Replaces various dash/hyphen symbols with common ones used in Japanese.

• Options: precedence (mapping priority order)
• Available mappings: "ascii", "jisx0201", "jisx0208_90", "jisx0208_90_windows", "jisx0208_verbatim"
• Example: 2019—2020 (em dash) → 2019-2020

6. Ideographic Annotations (ideographic-annotations)

Replaces ideographic annotations used in traditional Chinese-to-Japanese translation.

• Example: ㆖㆘ → 上下

7. IVS-SVS Base (ivs-svs-base)

Handles Ideographic and Standardized Variation Selectors.

• Options: charset, mode ("ivs-or-svs" or "base"), preferSVS, dropSelectorsAltogether
• Example: 葛󠄀 (葛 + IVS) → 葛

8. Japanese Iteration Marks (japanese-iteration-marks)

Expands iteration marks by repeating the preceding character.

• Example: 時々 → 時時, いすゞ → いすず

9. JIS X 0201 and Alike (jisx0201-and-alike)

Handles half-width/full-width character conversion.

• Options: fullwidthToHalfwidth, convertGL (alphanumerics/symbols), convertGR (katakana), u005cAsYenSign
• Example: ABC123 → ＡＢＣ１２３, ｶﾀｶﾅ → カタカナ

10. Kanji Old-New (kanji-old-new)

Converts old-style kanji (旧字体) to modern forms (新字体).

• Example: 舊字體の變換 → 旧字体の変換

11. Mathematical Alphanumerics (mathematical-alphanumerics)

Normalizes mathematical alphanumeric symbols to plain ASCII.

• Example: 𝐀𝐁𝐂 (mathematical bold) → ABC

12. Prolonged Sound Marks (prolonged-sound-marks)

Handles contextual conversion between hyphens and prolonged sound marks.

• Options: skipAlreadyTransliteratedChars, allowProlongedHatsuon, allowProlongedSokuon, replaceProlongedMarksFollowingAlnums
• Example: イ−ハト−ヴォ (with hyphen) → イーハトーヴォ (prolonged mark)

13. Radicals (radicals)

Converts CJK radical characters to their corresponding ideographs.

• Example: ⾔⾨⾷ (Kangxi radicals) → 言門食

14. Spaces (spaces)

Normalizes various Unicode space characters to standard ASCII space.

• Example: A　B (ideographic space) → A B

15. Roman Numerals (roman-numerals)

Converts Unicode Roman numeral characters to their ASCII letter equivalents.

• Example: Ⅰ Ⅱ Ⅲ → I II III, ⅰ ⅱ ⅲ → i ii iii

Installation

npm install @yosina-lib/yosina

Development

This project uses Node.js with TypeScript and Biome for formatting/linting.

# Install dependencies
npm install

# Run tests
npm test

# Run linting
npm run lint

# Run formatting
npm run format

# Build the library
npm run build

# Generate documentation
npm run docs:build

Requirements

• Node.js 18+
• TypeScript 5.0+

License

MIT