https://github.com/martinheidegger/monospace-char-width

A JavaScript CommonJS package that deals with double-width characters in monospace content
https://github.com/martinheidegger/monospace-char-width

Last synced: about 4 hours ago
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A JavaScript CommonJS package that deals with double-width characters in monospace content

• Host: GitHub
• URL: https://github.com/martinheidegger/monospace-char-width
• Owner: martinheidegger
• License: isc
• Created: 2015-10-24T14:21:57.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2015-10-31T18:37:12.000Z (almost 9 years ago)
• Last Synced: 2024-08-10T07:26:41.427Z (about 2 months ago)
• Language: JavaScript
• Size: 137 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: Readme.md
  • License: LICENSE.md

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# monospace-char-width

`monospace-char-width` is a JavaScript CommonJS package that deals with the fact that some characters in monospace font environments (like terminals) are displayed with the size of two characters while others occupy the space of one character.

It is derived (forked) from [visualwidth-js](https://github.com/tokuhirom/visualwidth-js) which is custom implemented and seems better tested with japanese than the similar package [wcwidth](https://github.com/timoxley/wcwidth) which is a derivate of [wcwidth.c](http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c). It differes from both of those packages by only returning the width of one character (as integer!) which is important for performance

reasons.

## Installation & Usage

Install the package with `npm i monospace-char-width --save` and pass the character you want to test like this:

```JavaScript

var mcw = require('monospace-char-width')

function charSize(string, pos) {

    mcw(string.charCodeAt(pos), pos > 0 ? string.charCodeAt(pos-1) : 0)

}

charSize('abcd', 0) // 1

```

## Surrogates or Why two character codes?

The size of some characters depends on surrogates which means that depending on the character before their size changes. For it to work appropriately you need to pass-in both the current character code and the one before that.