Simple Japanese Transliterator

A transliteration library that uses kuromoji to convert text between the different japanese alphabets.

Features

Transliterate hiragana / katakana / romaji / kanji
Split into syllables
Tokenization Wrapper around kuromoji
Extract furigana on a per-kanji level (as opposed to a token level offered by kuromoji)
Utility methods

Architecture

The main abstraction in this library is the Japanese[A] typeclass which defines a number of functions to work with japanese text. There are typeclass instances defined for String, Char and (kuromoji) Token, available out of the box.

Aside from that, the Kana class defines a number of methods specific to kana and has defined several sets of characters such as diacritics, etc., that should come in handy.

Usage

First, import a few things:

import sjt.JapaneseInstances._
import sjt.JapaneseSyntax._

With the String instance in scope, we convert transliterate string literals like this:

"tōkyō".toHiragana()
// String = とうきょう
"しゃっしん".toRomaji()
// String = shasshin
"ぎゅうにゅう".toKatakana()
// String = ギューニュー

Alternatively you can transliterate to hiragana, romaji and katakana at the same:

"としょかん".transliterate()
// Transliteration(としょかん,Kana(としょかん,トショカン,toshokan))

Kanji can also be transliterated but it needs to be tokenized so it's a more expensive operation:

"目標".transliterate()
// Transliteration(目標,Kana(もくひょう,モクヒョー,mokuhyō))

If you plan on transliterating things in bulk you should create a tokenizer instance before hand for better performance:

val cachedTokenizer = new Tokenizer()
...
"図書館".transliterate(cachedTokenizer)
// Transliteration(図書館,Kana(としょかん,トショカン,toshokan))
"猫はすごいです".transliterate(cachedTokenizer)
// Transliteration(猫はすごいです,Kana(ねこはすごいです,ネコ・ワ・スゴイ・デス,neko wa sugoi desu))

If you don't pass a tokenizer instance explicitly one will be created for you under the covers. Instanciating a tokenizer can take almost 1000ms cold and that is a huge amount of time so always be sure to pass one.

Split into syllables

The Japanese typeclass also defines syllabify which returns a List[(Kana, String)] with the syllables reversed:

"ゆうびんきょく".syllabify
// List[(sjt.Kana, String)] = List((Kana(く,ク,ku),く), (Kana(きょ,キョ,kyo),きょ), (Kana(ん,ン,n),ん), (Kana(び,ビ,bi),び), (Kana(ゆ,ユ,yu),ゆう))

Furigana

You can extract furigana for each kanji by using the furigana function:

"郵便局".furigana()
// Array[sjt.Transliteration] = Array(Transliteration(郵,Kana(ゆう,ユー,yū)), Transliteration(便,Kana(びん,ビン,bin)), Transliteration(局,Kana(きょく,キョク,kyoku)))

Utility functions

There are a number of functions defined by the Japanese typeclass, such as:

"言葉".containsKanji
// true

The Kana class also defines some utility methods as well as a number of sets of different kana:

import sjt.Kana._
val yoon = Kana.yoon
// Set[sjt.Kana] = Set(Kana(ちょ,チョ,cho), Kana(じゃ,ジャ,ja), Kana(きゃ,キャ,kya), Kana(ぢゅ,ヂュ,ju), Kana(きゅ,キュ,kyu), Kana(にょ,ニョ,nyo), Kana(しゃ,シャ,sha), Kana(じぇ,ジェ,je), Kana(ぎゅ,ギュ,gyu), Kana(りゃ,リャ,rya), Kana(ひゃ,ヒャ,hya), Kana(びゅ,ビュ,byu), Kana(びょ,ビョ,byo), Kana(ぢょ,ヂョ,jo), Kana(ちゅ,チュ,chu), Kana(ひょ,ヒョ,hyo), Kana(ぢゃ,ヂャ,ja), Kana(りゅ,リュ,ryu), Kana(しょ,ショ,sho), Kana(ひゅ,ヒュ,hyu), Kana(にゅ,ニュ,nyu), Kana(りょ,リョ,ryo), Kana(ちゃ,チャ,cha), Kana(ぎゃ,ギャ,gya), Kana(きょ,キョ,kyo), Kana(みゃ,ミャ,mya), Kana(にゃ,ニャ,nya), Kana(じょ,ジョ,jo), Kana(びゃ,ビャ,bya), Kana(じゅ,ジュ,ju), Kana(みょ,ミョ,myo), Kana(ぎょ,ギョ,gyo), Kana(しゅ,シュ,shu), Kana(みゅ,ミュ,myu))

ys.head.extendVowel()
// Kana(ちょう,チョー,chō)