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:
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.
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.
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, :ruby code is handled by CodeRay::Scanners::Ruby.
Scan a string in a given language into Tokens. This is the most common method to use. | |
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.
Scan and encode a string in a given language. | |
Encode the given tokens. | |
Scan a file, guess the language using FileType and encode it. |
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.
Create an Encoder instance with format and options. | |
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.
A Hash of all known token kinds and their associated CSS classes.
Assuming the path is a subpath of lib/coderay/
# File lib/coderay.rb, line 132 def self.coderay_path *path File.join CODERAY_PATH, *path end
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 196 def encode code, lang, format, options = {} encoder(format, options).encode code, lang, options 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 221 def encode_file filename, format, options = {} tokens = scan_file filename, :auto, get_scanner_options(options) encode_tokens tokens, format, options 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 209 def encode_tokens tokens, format, options = {} encoder(format, options).encode_tokens tokens, options 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 260 def encoder format, options = {} Encoders[format].new options 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 278 def get_scanner_options options options.fetch :scanner_options, {} end
Highlight a string into a HTML <div>.
CSS styles use classes, so you have to include a stylesheet in your output.
See encode.
# File lib/coderay.rb, line 232 def highlight code, lang, options = { :css => :class }, format = :div encode code, lang, format, options end
Highlight a file into a HTML <div>.
CSS styles use classes, so you have to include a stylesheet in your output.
See encode.
# File lib/coderay.rb, line 242 def highlight_file filename, options = { :css => :class }, format = :div encode_file filename, format, options 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 167 def scan code, lang, options = {}, &block # FIXME: return a proxy for direct-stream encoding TokensProxy.new code, lang, options, block 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::Text.
Calls CodeRay.scan.
Example:
require 'coderay' page = CodeRay.scan_file('some_c_code.c').html
# File lib/coderay.rb, line 183 def scan_file filename, lang = :auto, options = {}, &block lang = FileType.fetch filename, :text, true if lang == :auto code = File.read filename scan code, lang, options, &block end
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