encoder.rb
177 lines
| 5.2 KiB
| text/x-ruby
|
RubyLexer
Jean-Philippe Lang
|
r638 | require "stringio" | ||
| module CodeRay | ||||
| # This module holds the Encoder class and its subclasses. | ||||
| # For example, the HTML encoder is named CodeRay::Encoders::HTML | ||||
| # can be found in coderay/encoders/html. | ||||
| # | ||||
| # Encoders also provides methods and constants for the register | ||||
| # mechanism and the [] method that returns the Encoder class | ||||
| # belonging to the given format. | ||||
| module Encoders | ||||
| extend PluginHost | ||||
| plugin_path File.dirname(__FILE__), 'encoders' | ||||
| # = Encoder | ||||
| # | ||||
| # The Encoder base class. Together with Scanner and | ||||
| # Tokens, it forms the highlighting triad. | ||||
| # | ||||
| # Encoder instances take a Tokens object and do something with it. | ||||
| # | ||||
| # The most common Encoder is surely the HTML encoder | ||||
| # (CodeRay::Encoders::HTML). It highlights the code in a colorful | ||||
| # html page. | ||||
| # If you want the highlighted code in a div or a span instead, | ||||
| # use its subclasses Div and Span. | ||||
| class Encoder | ||||
| extend Plugin | ||||
| plugin_host Encoders | ||||
| attr_reader :token_stream | ||||
| class << self | ||||
| # Returns if the Encoder can be used in streaming mode. | ||||
| def streamable? | ||||
| is_a? Streamable | ||||
| end | ||||
| # If FILE_EXTENSION isn't defined, this method returns the | ||||
| # downcase class name instead. | ||||
| def const_missing sym | ||||
| if sym == :FILE_EXTENSION | ||||
| plugin_id | ||||
| else | ||||
| super | ||||
| end | ||||
| end | ||||
| end | ||||
| # Subclasses are to store their default options in this constant. | ||||
| DEFAULT_OPTIONS = { :stream => false } | ||||
| # The options you gave the Encoder at creating. | ||||
| attr_accessor :options | ||||
| # Creates a new Encoder. | ||||
| # +options+ is saved and used for all encode operations, as long | ||||
| # as you don't overwrite it there by passing additional options. | ||||
| # | ||||
| # Encoder objects provide three encode methods: | ||||
| # - encode simply takes a +code+ string and a +lang+ | ||||
| # - encode_tokens expects a +tokens+ object instead | ||||
| # - encode_stream is like encode, but uses streaming mode. | ||||
| # | ||||
| # Each method has an optional +options+ parameter. These are | ||||
| # added to the options you passed at creation. | ||||
| def initialize options = {} | ||||
| @options = self.class::DEFAULT_OPTIONS.merge options | ||||
| raise "I am only the basic Encoder class. I can't encode "\ | ||||
| "anything. :( Use my subclasses." if self.class == Encoder | ||||
| end | ||||
| # Encode a Tokens object. | ||||
| def encode_tokens tokens, options = {} | ||||
| options = @options.merge options | ||||
| setup options | ||||
| compile tokens, options | ||||
| finish options | ||||
| end | ||||
| # Encode the given +code+ after tokenizing it using the Scanner | ||||
| # for +lang+. | ||||
| def encode code, lang, options = {} | ||||
| options = @options.merge options | ||||
| scanner_options = CodeRay.get_scanner_options(options) | ||||
| tokens = CodeRay.scan code, lang, scanner_options | ||||
| encode_tokens tokens, options | ||||
| end | ||||
| # You can use highlight instead of encode, if that seems | ||||
| # more clear to you. | ||||
| alias highlight encode | ||||
| # Encode the given +code+ using the Scanner for +lang+ in | ||||
| # streaming mode. | ||||
| def encode_stream code, lang, options = {} | ||||
| raise NotStreamableError, self unless kind_of? Streamable | ||||
| options = @options.merge options | ||||
| setup options | ||||
| scanner_options = CodeRay.get_scanner_options options | ||||
| @token_stream = | ||||
| CodeRay.scan_stream code, lang, scanner_options, &self | ||||
| finish options | ||||
| end | ||||
| # Behave like a proc. The token method is converted to a proc. | ||||
| def to_proc | ||||
| method(:token).to_proc | ||||
| end | ||||
| # Return the default file extension for outputs of this encoder. | ||||
| def file_extension | ||||
| self.class::FILE_EXTENSION | ||||
| end | ||||
| protected | ||||
| # Called with merged options before encoding starts. | ||||
| # Sets @out to an empty string. | ||||
| # | ||||
| # See the HTML Encoder for an example of option caching. | ||||
| def setup options | ||||
| @out = '' | ||||
| end | ||||
| # Called with +text+ and +kind+ of the currently scanned token. | ||||
| # For simple scanners, it's enougth to implement this method. | ||||
| # | ||||
| # By default, it calls text_token or block_token, depending on | ||||
| # whether +text+ is a String. | ||||
| def token text, kind | ||||
| out = | ||||
| if text.is_a? ::String # Ruby 1.9: :open.is_a? String | ||||
| text_token text, kind | ||||
| elsif text.is_a? ::Symbol | ||||
| block_token text, kind | ||||
| else | ||||
| raise 'Unknown token text type: %p' % text | ||||
| end | ||||
| @out << out if @out | ||||
| end | ||||
| def text_token text, kind | ||||
| end | ||||
| def block_token action, kind | ||||
| case action | ||||
| when :open | ||||
| open_token kind | ||||
| when :close | ||||
| close_token kind | ||||
| else | ||||
| raise 'unknown block action: %p' % action | ||||
| end | ||||
| end | ||||
| # Called with merged options after encoding starts. | ||||
| # The return value is the result of encoding, typically @out. | ||||
| def finish options | ||||
| @out | ||||
| end | ||||
| # Do the encoding. | ||||
| # | ||||
| # The already created +tokens+ object must be used; it can be a | ||||
| # TokenStream or a Tokens object. | ||||
| def compile tokens, options | ||||
| tokens.each(&self) | ||||
| end | ||||
| end | ||||
| end | ||||
| end | ||||