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
Here‘s a fancy graphic to light up this gray docu:
See CodeRay, Encoders, Scanners, Tokens.
Remember you need RubyGems to use CodeRay, unless you have it in your load path. Run Ruby with -rubygems option if required.
require 'coderay' print CodeRay.scan('puts "Hello, world!"', :ruby).html # prints something like this: puts <span class="s">"Hello, world!"</span>
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
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.
The CodeRay module provides convenience methods for the engine.
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.
Read this to get a general view what CodeRay provides.
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, <tt>:ruby</tt> code is handled by CodeRay::Scanners::Ruby.
CodeRay.scan: | Scan a string in a given language into Tokens. This is the most common method to use. |
CodeRay.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 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.
CodeRay.encode: | Scan and encode a string in a given language. |
CodeRay.encode_tokens: | Encode the given tokens. |
CodeRay.encode_file: | Scan a file, guess the language using FileType and encode it. |
Streaming saves RAM by running Scanner and Encoder in some sort of pipe mode; see TokenStream.
CodeRay.scan_stream: | Scan in stream mode. |
CodeRay.encode: | Highlight a string with a given input and output format. |
You can use an Encoder instance to highlight multiple inputs. This way, the setup for this Encoder must only be done once.
CodeRay.encoder: | Create an Encoder instance with format and options. |
CodeRay.scanner: | Create an Scanner instance for lang, with ’’ as default code. |
To make use of CodeRay.scanner, use CodeRay::Scanner::code=.
The scanning methods provide more flexibility; we recommend to use these.
If you want to re-use scanners and encoders (because that is faster), see CodeRay::Duo for the most convenient (and recommended) interface.
VERSION | = | '0.8' | Version: Major.Minor.Teeny[.Revision] Major: 0 for pre-stable, 1 for stable Minor: feature milestone Teeny: development state, 0 for pre-release Revision: Subversion Revision number (generated on rake gem:make) |
Encode a string.
This scans code with the the Scanner for lang and then encodes it with the Encoder for format. options will be passed to the Encoder.
See CodeRay::Encoder.encode
# File lib/coderay.rb, line 206 206: def encode code, lang, format, options = {} 207: encoder(format, options).encode code, lang, options 208: end
Encodes filename (a path to a code file) with the Scanner for lang.
See CodeRay.scan_file. Notice that the second argument is the output format, not the input language.
Example:
require 'coderay' page = CodeRay.encode_file 'some_c_code.c', :html
# File lib/coderay.rb, line 241 241: def encode_file filename, format, options = {} 242: tokens = scan_file filename, :auto, get_scanner_options(options) 243: encode_tokens tokens, format, options 244: end
Encode a string in Streaming mode.
This starts scanning code with the the Scanner for lang while encodes the output with the Encoder for format. options will be passed to the Encoder.
See CodeRay::Encoder.encode_stream
# File lib/coderay.rb, line 195 195: def encode_stream code, lang, format, options = {} 196: encoder(format, options).encode_stream code, lang, options 197: end
Encode pre-scanned Tokens. Use this together with CodeRay.scan:
require 'coderay' # Highlight a short Ruby code example in a HTML span tokens = CodeRay.scan '1 + 2', :ruby puts CodeRay.encode_tokens(tokens, :span)
# File lib/coderay.rb, line 229 229: def encode_tokens tokens, format, options = {} 230: encoder(format, options).encode_tokens tokens, options 231: end
Finds the Encoder class for format and creates an instance, passing options to it.
Example:
require 'coderay' stats = CodeRay.encoder(:statistic) stats.encode("puts 17 + 4\n", :ruby) puts '%d out of %d tokens have the kind :integer.' % [ stats.type_stats[:integer].count, stats.real_token_count ] #-> 2 out of 4 tokens have the kind :integer.
# File lib/coderay.rb, line 270 270: def encoder format, options = {} 271: Encoders[format].new options 272: end
Extract the options for the scanner from the options hash.
Returns an empty Hash if :scanner_options is not set.
This is used if a method like CodeRay.encode has to provide options for Encoder and scanner.
# File lib/coderay.rb, line 288 288: def get_scanner_options options 289: options.fetch :scanner_options, {} 290: end
Convenience method for plugin loading. The syntax used is:
CodeRay.require_plugin '<Host ID>/<Plugin ID>'
Returns the loaded plugin.
# File lib/coderay/helpers/plugin.rb, line 323 323: def self.require_plugin path 324: host_id, plugin_id = path.split '/', 2 325: host = PluginHost.host_by_id(host_id) 326: raise PluginHost::HostNotFound, 327: "No host for #{host_id.inspect} found." unless host 328: host.load plugin_id 329: end
Scans the given code (a String) with the Scanner for lang.
This is a simple way to use CodeRay. Example:
require 'coderay' page = CodeRay.scan("puts 'Hello, world!'", :ruby).html
See also demo/demo_simple.
# File lib/coderay.rb, line 153 153: def scan code, lang, options = {}, &block 154: scanner = Scanners[lang].new code, options, &block 155: scanner.tokenize 156: end
Scans filename (a path to a code file) with the Scanner for lang.
If lang is :auto or omitted, the CodeRay::FileType module is used to determine it. If it cannot find out what type it is, it uses CodeRay::Scanners::Plaintext.
Calls CodeRay.scan.
Example:
require 'coderay' page = CodeRay.scan_file('some_c_code.c').html
# File lib/coderay.rb, line 169 169: def scan_file filename, lang = :auto, options = {}, &block 170: file = IO.read filename 171: if lang == :auto 172: require 'coderay/helpers/file_type' 173: lang = FileType.fetch filename, :plaintext, true 174: end 175: scan file, lang, options = {}, &block 176: end
Scan the code (a string) with the scanner for lang.
Calls scan.
See CodeRay.scan.
# File lib/coderay.rb, line 183 183: def scan_stream code, lang, options = {}, &block 184: options[:stream] = true 185: scan code, lang, options, &block 186: end