gojp / kana

Golang library for conversion between Japanese hiragana, katakana and romaji

kana

Golang library for convertiong hiragana to romaji, katakana to romaji, romaji to hiragana, and romaji to katakana.

Installation

Simply install with go get:

go get github.com/gojp/kana

Usage

Convert hiragana or katakana to romaji:

s := kana.KanaToRomaji("バナナ") // -> banana
s = kana.KanaToRomaji("かんじ") // -> kanji

Convert romaji to hiragana or katakana:

s := kana.RomajiToHiragana("kanji") // -> かんじ
s = kana.RomajiToKatakana("banana") // -> バナナ

Tell whether strings are written with kana, kanji or latin characters:

kana.IsLatin("banana") // -> true
kana.IsLatin("バナナ") // -> false

kana.IsKana("banana") // -> false
kana.IsKana("バナナ") // -> true

kana.IsKanji("banana") // -> false
kana.IsKanji("減少") // -> true

Normalize a romaji string to a standardized form (from the form given by Google Translate, for example):

kana.NormalizeRomaji("Myūjikku") // -> myu-jikku
kana.NormalizeRomaji("shitsuree") // -> shitsurei

Please feel free to use, contribute, and enjoy! You can also see this in action at nihongo.io.

• Herman Schaaf
• Shawn Smith

kana's Issues

ん not handled properly in some cases

For example, "zennin" should become "ぜんいん"

Kanji characters not being translated, but Hiragana characters are translated

kana.IsKanji("減少") recognises that it has Kanji characters but KanaToRomaji does not translate to Romaji it just leaves it as Kanji, Go Playground link below:

https://play.golang.org/p/qxeMAYoSqtk

So I can translate Hiragana characters but not Kanji characters, is that by design?

Documentation error

The readme says:

To use kana, you'll have to import it:

import "github.com/gojp/kana"
...
k := kana.NewKana()

However the library does not require an instance, and no such function is available.

Support for half-width hiragana/katakana/romaji

Would you be ok to add support for half-width characters?

On top of my head, what I believe would be useful functions:
IsFullWidth(s string) bool
IsHalfWidth(s string) bool
ToFullWidth(s string) string (replace every half width character with their full-width counterpart)
ToHalfWidth(s string) string

Note: converting half-width/full-width, is not that easy, because 'ガ' becomes 'ｶﾞ'.
If you are interested into adding it to the library, I can get working on a PR.

Is a whitespace considered a valid part of a Katakana string?

Hi, sorry for this stupid question, I know nothing about a Japanese and find this repo be very helpful, just don't know whether in Japanese is a whitespace allowed in a Katakana string. Thanks.

IsKatakana / IsHiragana being too permissive?

While working on the half-width support, I noticed that IsKatakana (as well as IsHiragana) are based on golang utf8 tables, and the range being used a probably too wide for what a japanese speaker would consider being a katakana or not.

For example, this was slightly unexpected:

• IsKatakana("ㇰ") = true // attention ㇰ != ク and ㇰ != ｸ
• IsKatakana("ｳｶ") = true

This even more:

• IsKatakana("㋾") = true

And I would say this is wrong:

• IsKatakana("㍓") = true

IsHiragana as fewer kirks, but still funny yet unexpected behavior. For example:

• IsHiragana("🈀") = true
• IsHiragana("𛁟") = true // \u1b05f

For IsKanji, I also suspect the range to be wider than what would make sense to a human reader, but considering the difficulty to put any kind of boundary to it, I've skipped checking.

ヂ is not handled correctly

The (rare) katakana 'ヂ' is not handled correctly in KanaToRomaji.

Test program:

package main

import (
    "fmt"

    "github.com/gojp/kana"
)

func main() {
	var test = "アイウエオダヂヅデド"
	fmt.Printf("Kana results: %s -> %s", test, kana.KanaToRomaji(test))
}

Output:
Kana results: アイウエオダヂヅデド -> aiueodaヂdudedo

Expected output:
Kana results: アイウエオダヂヅデド -> aiueodadidudedo

If you are interested, I can make a PR to fix it.

meccha = めcちゃ

should convert to めっちゃ