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 more accurate and recommended to split the string into graphemes (using libraries like graphemer) and calculate the width for those graphemes.

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
typecheck	run typechecker
lint	run lint tool
test	run tests
build	build script
clean	remove built script

License

MIT License

Author

Susisu (GitHub, Twitter)