From: MonkeeSage <MonkeeSage@...>
Date: 2007-12-06T04:50:15+09:00
Subject: Re: Keeping variables across requires?

On Dec 5, 1:13 pm, Peter Bunyan <peter.bun...@gmail.com> wrote:
> Ah, thanks. With Ruby I'm used to not having to do global/local things;
> I didn't know you could create global ones with $. But now I have
> another problem: The functions I created with lambda {} are now
> returning -1 as their arity.
>
> My new code:
>
> befunge.rb
> ---
>   elsif $instructions.include? operator
>     arguments = []
>     $instructions[operator].arity.times {arguments.push stack.pop}
>     $instructions[operator].call( *arguments )
>   else
> ---
>
> befunge-93.rb (just a sample)
> ---
>   $instructions = {}
>   $instructions["!"] = lambda { |a| stack.push !a}
>   $instructions["`"] = lambda { |a, b| stack.push b>a ? 1 : 0 }
>   $instructions[">"] = lambda { xvel = 1; yvel = 0 }
> ---
> --
> Posted viahttp://www.ruby-forum.com/.

Global state is usually unnecessary. It looks like your code would fit
naturally into a layout similar to this...

==befunge-93.rb==
require 'singleton'

class Befunge93
  include Singleton
  attr_accessor :instructions, :stack
  def initialize
    @stack = []
    @instructions = {}
    @instructions["!"] = lambda { | a |
      @stack.push(!a)
    }
    @instructions["`"] = lambda { | a, b |
      @stack.push(b>a ? 1 : 0)
    }
    @instructions[">"] = lambda {
      xvel = 1
      yvel = 0
    }
  end
end
====

==befunge.rb==
require 'befunge-93'

b = Befunge93.instance

#...
  elsif b.instructions.include?(operator)
    arguments = []
    b.instructions[operator].arity.times {
      arguments.push(b.stack.pop)
    }
    b.instructions[operator].call(*arguments)
  else
#...

Regards,
Jordan