ruby2html.rb

require 'ripper'
require 'cgi'

class Ruby2HTML < Ripper::Filter
  def on_default(event, tok, f)
    f << CGI.escapeHTML(tok)
  end

  private
  def respond_to?(name, priv = false)
    !!event_pattern_matching(name) or super
  end

  def method_missing(name, *args)
    if event = event_pattern_matching(name)
      tok, f = args
      f << %Q[<span class="#{event}">#{CGI.escapeHTML(tok)}</span>]
    else
      super
    end
  end

  def event_pattern_matching(on_name)
    on_name.to_s =~ /^on_(.+)$/ and Ripper::SCANNER_EVENTS.include? $1.to_sym and $1
  end
end

if $0 == __FILE__
  Ruby2HTML.new(ARGF).parse($stdout)
end

http://i.loveruby.net/w/RipperTutorial.TokenStreamInterface.html + すべての要素になんかしらのクラスを振る