NAME
  main.rb

SYNOPSIS
  a class factory and dsl for generating real main programs real quick

URI

  http://rubyforge.org/projects/codeforpeople/
  http://codeforpeople.com/lib/ruby/

INSTALL

  $sudo gem install main

DESCRIPTION
  main.rb is a library which simplifies and unifies the details of creating
  command line programs.  for instance, this program

    require 'main'

    Main {
      argument 'foo'
      option 'bar'

      def run
        p params['foo']
        p params['bar']
        exit_success!
      end
    }

  sets up a program which requires one argument, 'bar', and which may accept one
  command line switch, '--foo' in addition to the single option which is always
  accepted and handled appropriately: '--help', '-h'.

  for simple programs this is a real time saver but it's for more complex
  applications where main.rb's unification of parameter parsing, class
  configuration dsl, and auto-generation of usage messages can really streamline
  command line application development.  for example the following 'a.rb'
  program:

    require 'main'

    Main {
      argument('foo'){
        cast :int
      }
      keyword('bar'){
        arity 2
        cast :float
        defaults 0.0, 1.0
      }
      option('foobar'){
        argument :optional
        description 'the foobar option is very handy'
      }
      environment('BARFOO'){
        cast :list_of_bool
        synopsis 'export barfoo=value'
      }

      def run
        p params['foo'].value
        p params['bar'].values
        p params['foobar'].value
        p params['BARFOO'].value
      end
    }

  when run with a command line of

    BARFOO=true,false,false ruby a.rb 42 bar=40 bar=2 --foobar=a

  will produce

    42
    [40.0, 2.0]
    "a"
    [true, false, false]

  while a command line of

    ruby a.rb --help

  will produce

    NAME
      a.rb

    SYNOPSIS
      a.rb foo [bar=bar] [options]+

    PARAMETERS
      * foo [ 1 -> int(foo) ]

      * bar=bar [ 2 ~> float(bar=0.0,1.0) ]

      * --foobar=[foobar] [ 1 ~> foobar ]
          the foobar option is very handy