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

CLI

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 <NUMBER> ... It splits the given text by LF to make the
                                 width of each line shorter than the given
                                 number.
        -t, --text <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

Node.js

This module provides Node.js module.

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.

Development tools

• 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.