CodeRay Library¶ ↑

CodeRay is a Ruby library for syntax highlighting.

I try to make CodeRay easy to use and intuitive, but at the same time fully featured, complete, fast and efficient.

See README.

It consists mainly of

• the main engine: CodeRay (Scanners::Scanner, Tokens, Encoders::Encoder)

• the plugin system: PluginHost, Plugin

• the scanners in CodeRay::Scanners

• the encoders in CodeRay::Encoders

• the styles in CodeRay::Styles

Here's a fancy graphic to light up this gray docu:

Documentation¶ ↑

See CodeRay, Encoders, Scanners, Tokens.

Usage¶ ↑

Remember you need RubyGems to use CodeRay, unless you have it in your load path. Run Ruby with -rubygems option if required.

Highlight Ruby code in a string as html¶ ↑

require 'coderay'
print CodeRay.scan('puts "Hello, world!"', :ruby).html

# prints something like this:
puts <span class="s">&quot;Hello, world!&quot;</span>

Highlight C code from a file in a html div¶ ↑

require 'coderay'
print CodeRay.scan(File.read('ruby.h'), :c).div
print CodeRay.scan_file('ruby.h').html.div

You can include this div in your page. The used CSS styles can be printed with

% coderay_stylesheet

Highlight without typing too much¶ ↑

If you are one of the hasty (or lazy, or extremely curious) people, just run this file:

% ruby -rubygems /path/to/coderay/coderay.rb > example.html

and look at the file it created in your browser.

CodeRay Module¶ ↑

The CodeRay module provides convenience methods for the engine.

• The lang and format arguments select Scanner and Encoder to use. These are simply lower-case symbols, like :python or :html.

• All methods take an optional hash as last parameter, options, that is send to the Encoder / Scanner.

• Input and language are always sorted in this order: code, lang. (This is in alphabetical order, if you need a mnemonic ;)

You should be able to highlight everything you want just using these methods; so there is no need to dive into CodeRay's deep class hierarchy.

The examples in the demo directory demonstrate common cases using this interface.

Basic Access Ways¶ ↑

Read this to get a general view what CodeRay provides.

Scanning¶ ↑

Scanning means analysing an input string, splitting it up into Tokens. Each Token knows about what type it is: string, comment, class name, etc.

Each lang (language) has its own Scanner; for example, :ruby code is handled by CodeRay::Scanners::Ruby.

#scan

Scan a string in a given language into Tokens. This is the most common method to use.

#scan_file

Scan a file and guess the language using FileType.

The Tokens object you get from these methods can encode itself; see Tokens.

Encoding¶ ↑

Encoding means compiling Tokens into an output. This can be colored HTML or LaTeX, a textual statistic or just the number of non-whitespace tokens.

Each Encoder provides output in a specific format, so you select Encoders via formats like :html or :statistic.

#encode

Scan and encode a string in a given language.

#encode_tokens

Encode the given tokens.

#encode_file

Scan a file, guess the language using FileType and encode it.

All-in-One Encoding¶ ↑

#encode

Highlight a string with a given input and output format.

Instanciating¶ ↑

You can use an Encoder instance to highlight multiple inputs. This way, the setup for this Encoder must only be done once.

#encoder

Create an Encoder instance with format and options.

#scanner

Create an Scanner instance for lang, with '' as default code.

To make use of #scanner, use CodeRay::Scanner::code=.

The scanning methods provide more flexibility; we recommend to use these.

Reusing Scanners and Encoders¶ ↑

If you want to re-use scanners and encoders (because that is faster), see CodeRay::Duo for the most convenient (and recommended) interface.