eaw


The Node.js module to calculate the width of east Asian characters. (based on Unicode 9.0.0)

The script of this module is generated with [EastAsianWidth.txt] that Unicode Character Database provides.

- The generator script is [./scripts/generate.js].
- The generated script is [./lib/is-narrow-character.js].

The generator script is used to maintain this module as following to latest Unicode.

💿 Installation

This module can be installed by [npm].

$ npm install --save eaw

- It requires Node.js >=4.0.0.
- It can be used in browsers by [browserify]-like tools.

📖 Usage

$3

This module provides a CLI command: eaw

The command calculates the width of east Asian characters for each line.

``
Usage: eaw [OPTIONS]

It calculates the width of given east Asian characters.
It reads the characters from stdin or --text option.

OPTIONS:
-s, --split ... It splits the given text by LF to make the
width of each line shorter than the given
number.
-t, --text ...... The characters that eaw processes instead of
stdin.

Example:
$ eaw --text "hello, 世界"
11
$ cat hello.txt | eaw
11
$ cat hello.txt | eaw --split 4
hell
o,
世界
`

$3

This module provides Node.js module.

`js
const eaw = require("eaw")

console.log(eaw.isNarrowCharacter("A")) // → true
console.log(eaw.isNarrowCharacter("あ")) // → false
console.log(eaw.getWidth("A")) // → 1
console.log(eaw.getWidth("あ")) // → 2
console.log(eaw.getWidth("hello, 世界")) // → 11
console.log(eaw.getWidth(["hello, 世界", "🌟❤"])) // → [11, 4]
console.log(eaw.split("hello, 世界", 4)) // → ["hell", "o, ", "世界"]
console.log(eaw.split(["hello, 世界", "🌟❤👍"], 4)) // → ["hell", "o, ", "世界", "🌟❤", "👍"]

process.stdin
.pipe(eaw.createWidthStream())
.pipe(process.stdout)

process.stdin
.pipe(eaw.createSplitStream(4))
.pipe(process.stdout)
`

> eaw.isNarrowCharacter(character: string): boolean

It checks whether the given character is a narrow character or not.

This function checks the first code point if the argument has 2 or more characters.

> eaw.getWidth(characters: string, widthOfWideCharacters?: number = 2): number

> eaw.getWidth(characters: string[], widthOfWideCharacters?: number = 2): number[]

> eaw.getWidth(characters: Iterable<string>, widthOfWideCharacters?: number = 2): Iterable<number>

It returns the total width of the given characters.

> eaw.split(characters: string, maxPerLine: number, widthOfWideCharacters?: number = 2): string[]

> eaw.split(characters: string[], maxPerLine: number, widthOfWideCharacters?: number = 2): string[]

> eaw.split(characters: Iterable<string>, maxPerLine: number, widthOfWideCharacters?: number = 2): Iterable<string>

It splits the given characters to make the width of each line shorter than the given number.

> eaw.createWidthStream(widthOfWideCharacters?: number = 2): [stream.Transform]

It returns the transform stream to calculate the width of each line.

> eaw.createSplitStream(maxPerLine: number, widthOfWideCharacters?: number = 2): [stream.Transform]

It returns the transform stream to split the given characters to make the width of each line shorter than the given number.

📰 Changelog

See [GitHub Releases]

💪 Contributing

Welcom your contributing!

Please use GitHub's issues/PRs.

$3

- npm test runs tests.
- npm run build generates the script from [EastAsianWidth.txt].
- npm run clean removes the coverage result of the last npm test command.
- npm run coverage opens the coverage of the last npm test command by browsers.
- npm run lint runs [ESLint].
- npm run watch` runs tests for each file change.

[EastAsianWidth.txt]: http://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt
[./scripts/generate.js]: ./scripts/generate.js
[./lib/is-narrow-character.js]: ./lib/is-narrow-character.js
[npm]: https://www.npmjs.com/
[browserify]: http://browserify.org/
[stream.Transform]: https://nodejs.org/api/stream.html#stream_class_stream_transform
[GitHub Releases]: https://github.com/mysticatea/eaw/releases
[ESLint]: http://eslint.org/