# Rouge [![Build Status](https://github.com/rouge-ruby/rouge/actions/workflows/ruby.yml/badge.svg)](https://github.com/rouge-ruby/rouge/actions/workflows/ruby.yml) [![Gem Version](https://badge.fury.io/rb/rouge.svg)](https://rubygems.org/gems/rouge) [![YARD Docs](http://img.shields.io/badge/yard-docs-blue.svg)](https://rouge-ruby.github.io/docs/) [Rouge][] is a pure Ruby syntax highlighter. It can highlight [over 200 different languages][languages-doc], and output HTML or ANSI 256-color text. Its HTML output is compatible with stylesheets designed for [Pygments][]. [rouge]: http://rouge.jneen.net/ "Rouge" [languages-doc]: https://rouge-ruby.github.io/docs/file.Languages.html "Languages" [pygments]: http://pygments.org "Pygments" ## Installation In your Gemfile, add: ```ruby gem 'rouge' ``` or ```bash gem install rouge ``` ## Usage Rouge's most common uses are as a Ruby library, as part of Jekyll and as a command line tool. ### Library Here's a quick example of using Rouge as you would any other regular Ruby library: ```ruby require 'rouge' # make some nice lexed html source = File.read('/etc/bashrc') formatter = Rouge::Formatters::HTML.new lexer = Rouge::Lexers::Shell.new formatter.format(lexer.lex(source)) # Get some CSS Rouge::Themes::Base16.mode(:light).render(scope: '.highlight') # Or use Theme#find with string input Rouge::Theme.find('base16.light').render(scope: '.highlight') ``` ### Jekyll Rouge is Jekyll's default syntax highlighter. Out of the box, Rouge will be used to highlight text wrapped in the `{% highlight %}` template tags. The `{% highlight %}` tag provides minimal options: you can specify the language to use and whether to enable line numbers or not. More information is available in [the Jekyll docs][j-docs]. [j-docs]: https://jekyllrb.com/docs/liquid/tags/#code-snippet-highlighting "Code snippet highlighting in the Jekyll documentation" ### Command Line Rouge ships with a `rougify` command which allows you to easily highlight files in your terminal: ```console $ rougify foo.rb $ rougify foo.rb -t monokai.sublime $ rougify style monokai.sublime > syntax.css ``` ## Configuration ### Formatters Rouge comes with a number of formatters built-in but as of Rouge 2.0, you are encouraged to write your own formatter if you need something custom. The built-in formatters are: - `Rouge::Formatters::HTML.new` will render your code with standard class names for tokens, with no div-wrapping or other bells or whistles. - `Rouge::Formatters::HTMLInline.new(theme)` will render your code with no class names, but instead inline the styling options into the `style=` attribute. This is good for emails and other systems where CSS support is minimal. - `Rouge::Formatters::HTMLLinewise.new(formatter, class: 'line-%i')` will split your code into lines, each contained in its own div. The `class` option will be used to add a class name to the div, given the line number. - `Rouge::Formatters::HTMLLineHighlighter.new(formatter, highlight_lines: [3, 5])` will split your code into lines and wrap the lines specified by the `highlight_lines` option in a span with a class name specified by the `highlight_line_class` option (default: `hll`). - `Rouge::Formatters::HTMLLineTable.new(formatter, opts={})` will output an HTML table containing numbered lines, each contained in its own table-row. Options are: - `start_line: 1` - the number of the first row - `line_id: 'line-%i'` - a `sprintf` template for `id` attribute with current line number - `line_class: 'lineno'` - a CSS class for each table-row - `table_class: 'rouge-line-table'` - a CSS class for the table - `gutter_class: 'rouge-gutter'` - a CSS class for the line-number cell - `code_class: 'rouge-code'` - a CSS class for the code cell - `Rouge::Formatters::HTMLPygments.new(formatter, css_class='codehilite')` wraps the given formatter with div wrappers generally expected by stylesheets designed for Pygments. - `Rouge::Formatters::HTMLTable.new(formatter, opts={})` will output an HTML table containing numbered lines similar to `Rouge::Formatters::HTMLLineTable`, except that the table from this formatter has just a single table-row. Therefore, while the table is more DOM-friendly for JavaScript scripting, long code lines will mess with the column alignment. Options are: - `start_line: 1` - the number of the first line - `line_format: '%i'` - a `sprintf` template for the line number itself - `table_class: 'rouge-table'` - a CSS class for the table - `gutter_class: 'rouge-gutter'` - a CSS class for the gutter - `code_class: 'rouge-code'` - a CSS class for the code column - `Rouge::Formatters::HTMLLegacy.new(opts={})` is a backwards-compatibility class intended for users of Rouge 1.x, with options that were supported then. Options are: - `inline_theme: nil` - use an HTMLInline formatter with the given theme - `line_numbers: false` - use an HTMLTable formatter - `wrap: true` - use an HTMLPygments wrapper - `css_class: 'codehilite'` - a CSS class to use for the Pygments wrapper - `Rouge::Formatters::Terminal256.new(theme)` is a formatter for generating highlighted text for use in the terminal. `theme` must be an instance of `Rouge::Theme`, or a `Hash` structure with `:theme` entry. - `Rouge::Formatters::TerminalTruecolor.new(theme)` is similar to the previous, except it outputs ANSI truecolor codes, instead of approximating with a 256-color scheme. - `Rouge::Formatters::Tex.new` is a formatter for TeX systems which wraps each token with an `\RG{toktype}{text}` tag. You can then use `rougify style mystyle --tex` to generate definitions for these tags and the surrounding environment. #### Writing your own HTML formatter For the majority of applications, there are custom requirements for presenting highlighted text, as HTML or otherwise. In these cases, rather than patching or post-processing the output of Rouge, it is usually better to **write your own formatter**. This may sound intimidating, but it is actually quite easy! All you have to do is subclass `Rouge::Formatter`, define a `tag`, and implement a method `#stream(tokens, &block)`, which receives an Enumerable of token/value pairs, and yields out chunks of strings which will be concatenated. The `Formatter` base class contains the helper method `#token_lines(stream, &block)`, which separates tokens into distinct lines, and `Rouge::Formatters::HTML` contains the helper `#span(token, value)` to escape and render standard `` tags for HTML. Alternatively, if you want to override how individual spans are rendered, you can override `#safe_span(token, safe_value)`, which will be passed the token type and pre-escaped content for the token. ```ruby class MyFormatter < Rouge::Formatters::HTML # this is the main entry method. override this to customize the behavior of # the HTML blob as a whole. it should receive an Enumerable of (token, value) # pairs and yield out fragments of the resulting html string. see the docs # for the methods available on Token. def stream(tokens, &block) yield "
" tokens.each do |token, value| # for every token in the output, we render a span yield span(token, value) end yield "
" end # or, if you need linewise processing, try: def stream(tokens, &block) token_lines(tokens).each do |line_tokens| yield "
" line_tokens.each do |token, value| yield span(token, value) end yield "
" end end # Override this method to control how individual spans are rendered. # The value `safe_value` will already be HTML-escaped. def safe_span(token, safe_value) # in this case, "text" tokens don't get surrounded by a span if token == Token::Tokens::Text safe_value else "#{safe_value}" end end end ``` ### Lexer Options - `debug: true` will print a trace of the lex on stdout. For safety, this only works if `Rouge::Lexer.enable_debug!` has been called. - `parent: ''` allows you to specify which language the template is inside. ### Theme Options - `scope: '.highlight'` sets the CSS selector to which styles are applied, e.g.: ```ruby Rouge::Themes::MonokaiSublime.render(scope: 'code') ``` ## Documentation Rouge's documentation is available at [rouge-ruby.github.io/docs/][docs]. [docs]: https://rouge-ruby.github.io/docs "Rouge's official documentation" ## Requirements ### Ruby Rouge is compatible with all versions of Ruby from 3.0 onwards. It has no external dependencies. ### Encodings Rouge only supports UTF-8 strings. If you'd like to highlight a string with a different encoding, please convert it to UTF-8 first. ## Integrations - Middleman: - [middleman-syntax][] (@bhollis) - [middleman-rouge][] (@Linuus) - RDoc: [rdoc-rouge][] (@zzak) - Rails: [Rouge::Rails][] (@jacobsimeon) [middleman-syntax]: https://github.com/middleman/middleman-syntax [middleman-rouge]: https://github.com/Linuus/middleman-rouge [rdoc-rouge]: https://github.com/zzak/rdoc-rouge [rouge::rails]: https://github.com/jacobsimeon/rouge-rails ## Contributing We're always excited to welcome new contributors to Rouge. By it's nature, a syntax highlighter relies for its success on submissions from users of the languages being highlighted. You can help Rouge by filing bug reports or developing new lexers. Everyone interacting in Rouge and its sub-projects' code bases is expected to follow the Rouge [Code of Conduct][code-of-conduct]. [code-of-conduct]: CODE_OF_CONDUCT.md ### Bug Reports Rouge uses GitHub's Issues to report bugs. You can [choose][issue-chooser] from one of our templates or create a custom issue. Issues that have not been active for a year are automatically closed by GitHub's [Probot][]. [issue-chooser]: https://github.com/rouge-ruby/rouge/issues/new/choose "Choose an issue from the templates" [probot]: https://probot.github.io "Read more about GitHub's Probot" ### Developing Lexers **NOTE**: Please don't submit lexers that are copy-pasted from other files. These submission will be rejected and we don't want you to waste your time. We want to make it as easy as we can for anyone to contribute a lexer to Rouge. To help get you started, we have [a guide][lexer-dev-doc] on lexer development in the documentation. The best place is to start there. [lexer-dev-doc]: https://rouge-ruby.github.io/docs/file.LexerDevelopment.html "Rouge's lexer development guide" If you get stuck and need help, submit a pull request with what you have and make it clear in your submission that the lexer isn't finished yet. We'll do our best to answer any questions you have and sometimes the best way to do that is with actual code. If your language is internal or obscure, or it is taking far too long to merge into baseline Rouge, you can very easily write a plugin for language support. Check out our [plugin example repository][plugin-example] for a good starting point. [plugin-example]: https://github.com/rouge-ruby/rouge-plugin-example "Rouge Plugin Example" ### Testing Rouge Once you've cloned the repository from GitHub, you can test the core of Rouge simply by running `rake` (no `bundle exec` required). You can also run a single test file by setting the `TEST` environment variable to the path of the desired test. For example, to test just the _`ruby` lexer_ (located at path `spec/lexers/ruby_spec.rb`) simply run the following: ```bash TEST=spec/lexers/ruby_spec.rb rake ``` To test a lexer visually, run `puma` from the top-level working directory and you should have a web server running and ready to go. Visit to see the full list of Rouge's lexers. Once you've selected a particular lexer, you can add `?debug=1` to your URL string to see a lot of helpful debugging info printed on stdout. ## Maintainers Rouge is largely the result of the hard work of unpaid volunteers. It was originally developed by Jeanine Adkisson (@jneen) and is currently maintained by Jeanine Adkisson, Drew Blessing (@dblessing), Goro Fuji (@gfx) and Tan Le (@tancnle). ## License Rouge is released under the MIT license. Please see the [LICENSE][license] file for more information. [license]: LICENSE