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https://github.com/rouge-ruby/rouge

A pure Ruby code highlighter that is compatible with Pygments
https://github.com/rouge-ruby/rouge

minitest rubocop ruby syntax-highlighting

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A pure Ruby code highlighter that is compatible with Pygments

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README 

        
# 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:



```bash

rougify foo.rb

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.



#### Writing your own HTML formatter



If the above formatters are not sufficient, and you wish to customize the layout

of the HTML document, we suggest writing your own HTML formatter. This can be

accomplished by subclassing `Rouge::Formatters::HTML` and overriding specific

methods:



```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: false` will print a trace of the lex on stdout.



- `parent: ''` allows you to specify which language the template is inside.



### CSS 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 2.0.0 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 shiny new 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.



### 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 `rackup` 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.



## Versioning



Rouge uses [Semantic Versioning 2.0.0][sv2].



[sv2]: http://semver.org/



## 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