Chris@909: module CodeRay
Chris@909: module Encoders
Chris@909:   
Chris@909:   # A Filter encoder has another Tokens instance as output.
Chris@909:   # It can be subclass to select, remove, or modify tokens in the stream.
Chris@909:   # 
Chris@909:   # Subclasses of Filter are called "Filters" and can be chained.
Chris@909:   # 
Chris@909:   # == Options
Chris@909:   # 
Chris@909:   # === :tokens
Chris@909:   # 
Chris@909:   # The Tokens object which will receive the output.
Chris@909:   # 
Chris@909:   # Default: Tokens.new
Chris@909:   # 
Chris@909:   # See also: TokenKindFilter
Chris@909:   class Filter < Encoder
Chris@909:     
Chris@909:     register_for :filter
Chris@909:     
Chris@909:   protected
Chris@909:     def setup options
Chris@909:       super
Chris@909:       
Chris@909:       @tokens = options[:tokens] || Tokens.new
Chris@909:     end
Chris@909:     
Chris@909:     def finish options
Chris@909:       output @tokens
Chris@909:     end
Chris@909:     
Chris@909:   public
Chris@909:     
Chris@909:     def text_token text, kind  # :nodoc:
Chris@909:       @tokens.text_token text, kind
Chris@909:     end
Chris@909:     
Chris@909:     def begin_group kind  # :nodoc:
Chris@909:       @tokens.begin_group kind
Chris@909:     end
Chris@909:     
Chris@909:     def begin_line kind  # :nodoc:
Chris@909:       @tokens.begin_line kind
Chris@909:     end
Chris@909:     
Chris@909:     def end_group kind  # :nodoc:
Chris@909:       @tokens.end_group kind
Chris@909:     end
Chris@909:     
Chris@909:     def end_line kind  # :nodoc:
Chris@909:       @tokens.end_line kind
Chris@909:     end
Chris@909:     
Chris@909:   end
Chris@909:   
Chris@909: end
Chris@909: end