emphasize

ANSI syntax highlighting in for your terminal. Like highlight.js (through lowlight).

emphasize supports all 191 syntaxes of highlight.js. There are three builds of emphasize:

• lib/core.js — 0 languages
• lib/common.js (default) — 35 languages
• lib/all.js — 191 languages

Install

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

npm:

npm install emphasize

Use

Say example.css looks as follows:

@font-face {
  font-family: Alpha;
  src: url('Bravo.otf');
}

body, .charlie, #delta {
  color: #bada55;
  background-color: rgba(33, 33, 33, 0.33);
  font-family: "Alpha", sans-serif;
}

@import url(echo.css);

@media print {
  a[href^=http]::after {
    content: attr(href)
  }
}

And example.js contains the following:

import fs from 'fs'
import {emphasize} from 'emphasize'

const doc = String(fs.readFileSync('example.css'))

const output = emphasize.highlightAuto(doc).value

console.log(output)

Now, running node example yields:

\x1B[32m@font-face\x1B[39m {
  \x1B[33mfont-family\x1B[39m: Alpha;
  \x1B[33msrc\x1B[39m: \x1B[31murl\x1B[39m(\x1B[36m'Bravo.otf'\x1B[39m);
}

\x1B[32mbody\x1B[39m, \x1B[34m.charlie\x1B[39m, \x1B[34m#delta\x1B[39m {
  \x1B[33mcolor\x1B[39m: \x1B[36m#bada55\x1B[39m;
  \x1B[33mbackground-color\x1B[39m: \x1B[31mrgba\x1B[39m(\x1B[36m33\x1B[39m, \x1B[36m33\x1B[39m, \x1B[36m33\x1B[39m, \x1B[36m0.33\x1B[39m);
  \x1B[33mfont-family\x1B[39m: \x1B[36m"Alpha"\x1B[39m, sans-serif;
}

\x1B[32m@import\x1B[39m url(echo.css);

\x1B[32m@media\x1B[39m print {
  \x1B[32ma\x1B[39m\x1B[35m[href^=http]\x1B[39m\x1B[35m::after\x1B[39m {
    \x1B[33mcontent\x1B[39m: \x1B[31mattr\x1B[39m(href)
  }
}

And looks as follows:

API

This package exports the following identifiers: emphasize. There is no default export.

emphasize.registerLanguage(name, syntax)

Register a syntax. Like low.registerLanguage().

emphasize.highlight(language, value[, sheet])

Highlight value as a language grammar. Like low.highlight(), but the return object’s value property is a string instead of a hast root.

You can pass in a sheet (Sheet?, optional) to configure the theme.

emphasize.highlightAuto(value[, sheet | options])

Highlight value by guessing its grammar. Like low.highlightAuto(), but the return object’s value property is a string instead of a hast root.

You can pass in a sheet (Sheet?, optional) directly or as options.sheet to configure the theme.

Sheet

A sheet is an object mapping highlight.js classes to functions. The hljs- prefix must not be used in those classes. The “descendant selector” (a space) is supported.

Those functions receive a value (string), which they should wrap in ANSI sequences and return. For convenience, chalk’s chaining of styles is suggested.

An abbreviated example is as follows:

{
  'comment': chalk.gray,
  'meta meta-string': chalk.cyan,
  'meta keyword': chalk.magenta,
  'emphasis': chalk.italic,
  'strong': chalk.bold,
  'formula': chalk.inverse
}

Emphasize in the browser

If you’re using emphasize/lib/core.js, no syntaxes are included. Some syntaxes are included if you import emphasize (or emphasize/lib/common.js). All syntaxes are available through emphasize/lib/all.js

See Syntaxes in lowlight for which syntaxes are included where.

License

MIT © Titus Wormer