From: Louis J Scoras <louis.j.scoras@...>
Date: 2006-11-19T23:11:52+09:00
Subject: Re: [QUIZ] Literate Ruby (#102)

#!/usr/bin/env ruby
#
# RLit (0.1)
# Author: Louis J. Scoras <louis.j.scoras@gmail.com>
# Date: Sat Nov 18 23:29:29 EST 2006
#
# RLit -- a simple script for enabling literate programming in Ruby using erb
#         and BlueCloth.
#
# It is licensed under the same terms as ruby.
#
# I think it's proper form to send the code for solutions in the body
of the mail, so
# I'm just sending the regular ruby code to the list.  If you want to
see the literate
# version check out it out here:
#
#     http://www.ljstech.net/articles/rlit.html
#
# This solution is a pretty simple one, but by leveraging erb and BlueCloth it
# makes getting an html version of the document really easy.
#

require 'rubygems'
require 'bluecloth'
require 'cgi'
require 'erb'
require 'optparse'

module RLit
  class Processor
    attr_reader :html, :code

    def initialize(io, which_chunk)
      corpus  = io.read
      @prog   = ERB.new(corpus, nil, '%<>')
      @chunks = Hash.new {|h,k| h[k] = ''}
      @html, @code = do_html, do_code(which_chunk)
    end

    def chunk c
      r,ch = nil,nil
      c.each do |chunk, code|
        @chunks[chunk] << code
        r = code
        ch = chunk
      end
      "<div class=\"caption\">:#{ch}</div>\n<pre><code>#{CGI.escapeHTML(r)}</code></pre>"
    end

    def ref c
      t = ERB.new(@chunks[c])
      t.result(binding)
    end

    def do_html
      doc = @prog.result(binding)
      '<link rel="stylesheet" href="style.css" type="text/css" />' +
      BlueCloth.new(doc).to_html
    end

    def do_code(which_chunk)
      return unless which_chunk
      t = ERB.new(@chunks[which_chunk])
      t.result(binding)
    end

    private :do_html, :do_code

  end
end

def usage(opts)
  puts opts; exit
end

method, arg = nil, nil

opts = OptionParser.new do |o|
  o.banner = "Usage: #{File.basename $0} output_method FILE(s)"
  o.separator ''
  o.separator "output_method can be either"
  o.on('-d','--documentation', 'Output the document') {
    method = :html
  }
  o.on('-c','--code [CHUNK_NAME]', 'Output the code for the
interpreter') {|chunk|
    arg = chunk
    method = :code
  }
  o.separator ''
  o.separator "Other options"
  o.on('-h','--help', 'Print this help message') {
    usage(o)
  }
end

opts.parse!(ARGV)

unless method
  puts "Invalid Arguments: Must specify an output method"
  usage(opts)
end

p = RLit::Processor.new(ARGF, arg && arg.to_sym) #chunk)
puts p.__send__(method)