meaw

Utilities for Unicode East Asian Width (EAW).

Installation

# npm
npm i --save meaw
# yarn
yarn add meaw
# pnpm
pnpm add meaw

Usage

`getEAW()`

Gets the EAW property of a character.

import { getEAW } from "meaw";

// Narrow
assert(getEAW("A") === "Na");
// Wide
assert(getEAW("あ") === "W");
assert(getEAW("安") === "W");
assert(getEAW("🍣") === "W");
// Fullwidth
assert(getEAW("Ａ") === "F");
// Halfwidth
assert(getEAW("ｱ") === "H");
// Ambiguous
assert(getEAW("∀") === "A");
assert(getEAW("→") === "A");
assert(getEAW("Ω") === "A");
assert(getEAW("Я") === "A");
// Neutral
assert(getEAW("ℵ") === "N");

// character position (in code unit) can be specified
assert(getEAW("ℵAあＡｱ∀", 2) === "W");

`computeWidth()`

Deprecated. To calculate the visual width of a string, it is recommended to split the string into graphemes (using Intl.Segmenter or libraries like graphemer) and then calculate the widths of them.

Computes an approximate width of a string based on the EAW properties of the characters. By default, characters with property Wide (W) or Fullwidth (F) are treated as wide (= 2) and others are as narrow (= 1).

import { computeWidth } from "meaw";

assert(computeWidth("Aあ🍣Ω") === 6);
// character width for each EAW property can be customized
assert(computeWidth("Aあ🍣Ω", { "A": 2 }) === 7);

Development

Setup

git clone https://github.com/susisu/meaw.git
cd meaw
pnpm i

Scripts

Name	Description
`fetch`	fetch the latest version of the EAW definition file
`generate`	generate source script from the EAW definition file
`format`	run Prettier
`lint`	run ESLint
`typecheck`	run `tsc --noEmit`
`test`	execute tests
`build`	build scripts