Redmine/vendor/gems/coderay-0.9.7/lib/coderay.rb

323 lines
9.8 KiB
Ruby

# = 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/TokenStream, Encoders::Encoder), PluginHost
# * the scanners in CodeRay::Scanners
# * the encoders in CodeRay::Encoders
#
# Here's a fancy graphic to light up this gray docu:
#
# http://cycnus.de/raindark/coderay/scheme.png
#
# == 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 <tt>:python</tt> or <tt>:html</tt>.
# * 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, <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
#
# 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 <tt>:html</tt> or <tt>:statistic</tt>.
#
# 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
#
# Streaming saves RAM by running Scanner and Encoder in some sort of
# pipe mode; see TokenStream.
#
# CodeRay.scan_stream:: Scan in stream mode.
#
# == All-in-One Encoding
#
# CodeRay.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.
#
# 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.
#
# == 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.
module CodeRay
$CODERAY_DEBUG ||= false
# 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)
VERSION = '0.9.7'
require 'coderay/tokens'
require 'coderay/token_classes'
require 'coderay/scanner'
require 'coderay/encoder'
require 'coderay/duo'
require 'coderay/style'
class << self
# 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.
def scan code, lang, options = {}, &block
scanner = Scanners[lang].new code, options, &block
scanner.tokenize
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
def scan_file filename, lang = :auto, options = {}, &block
file = IO.read filename
if lang == :auto
require 'coderay/helpers/file_type'
lang = FileType.fetch filename, :plaintext, true
end
scan file, lang, options = {}, &block
end
# Scan the +code+ (a string) with the scanner for +lang+.
#
# Calls scan.
#
# See CodeRay.scan.
def scan_stream code, lang, options = {}, &block
options[:stream] = true
scan code, lang, options, &block
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
def encode_stream code, lang, format, options = {}
encoder(format, options).encode_stream code, lang, options
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
def encode code, lang, format, options = {}
encoder(format, options).encode code, lang, 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.
def highlight code, lang, options = { :css => :class }, format = :div
encode code, lang, 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)
#
def encode_tokens tokens, format, options = {}
encoder(format, options).encode_tokens tokens, 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
def encode_file filename, format, options = {}
tokens = scan_file filename, :auto, get_scanner_options(options)
encode_tokens tokens, 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.
def highlight_file filename, options = { :css => :class }, format = :div
encode_file filename, format, 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.
def encoder format, options = {}
Encoders[format].new options
end
# Finds the Scanner class for +lang+ and creates an instance, passing
# +options+ to it.
#
# See Scanner.new.
def scanner lang, options = {}
Scanners[lang].new '', options
end
# Extract the options for the scanner from the +options+ hash.
#
# Returns an empty Hash if <tt>:scanner_options</tt> is not set.
#
# This is used if a method like CodeRay.encode has to provide options
# for Encoder _and_ scanner.
def get_scanner_options options
options.fetch :scanner_options, {}
end
end
# This Exception is raised when you try to stream with something that is not
# capable of streaming.
class NotStreamableError < Exception
def initialize obj
@obj = obj
end
def to_s
'%s is not Streamable!' % @obj.class
end
end
# A dummy module that is included by subclasses of CodeRay::Scanner an CodeRay::Encoder
# to show that they are able to handle streams.
module Streamable
end
end
# Run a test script.
if $0 == __FILE__
$stderr.print 'Press key to print demo.'; gets
# Just use this file as an example of Ruby code.
code = File.read(__FILE__)[/module CodeRay.*/m]
print CodeRay.scan(code, :ruby).html
end