From: TRANS <transfire@...>
Date: 2007-07-07T21:38:51+09:00
Subject: GetoptLong w/ DSL

Hi--

Thought I'd share this little piece of code. It provides the option of
using a little DSL for GetoptLong, rather than the argument constants.
Eg.

  GetoptLong.new do
    flag :help, :h
    required :name
  end

Instead of:

  GetoptLong.new([
    [ :help, :h, GetoptLong::NO_ARGUMENT ],
    [ :name, GetoptLong::REQUIRED_ARGUMENT ]
  ])

Maybe, with a little touching-up, it be a good patch to the standard lib?

T.


  require 'getoptlong'

  class GetoptLong

    alias :init :initialize

    def initialize(*arguments, &block)
      if block_given?
        raise ArgumentError unless arguments.empty?
        arguments = DSL.new(&block).arguments
      end
      init(*arguments)
    end

    # DSL-mode parser.

    class DSL
      attr :arguments

      def initialize(&block)
        @arguments = []
        instance_eval(&block)
      end

      def flag(*opts)
        @arguments << (opts << GetoptLong::NO_ARGUMENT)
      end

      def required(*opts)
        @arguments << (opts <<  GetoptLong::REQUIRED_ARGUMENT)
      end
      alias :reqs :required

      def optional(*opts)
        @arguments << (opts << GetoptLong::OPTIONAL_ARGUMENT)
      end
      alias :opts :optional
    end

  end