From: Trans <transfire@...>
Date: 2005-09-12T13:21:31+09:00
Subject: Re: Array#[]=

hmmm....

  # holds some nift binding methods like []=
  # for setting local vars, essentially
  #
  #   eval %{ #{var}=#{val} }, binding
  #
  require 'nano/binding'

  class Array
    def to_p(bind)
      P.new(bind,*self)
    end
  end

  class P < Array
    attr_reader :bind
    def initialize(*args)
      super()
      @bind = args.shift if Binding === args.first
      self.replace(args)
    end
    def ===(args)
      if size == args.size
        each_with_index{ |k, i|
          args.bind[k] = args[i]
        }
        return true
      else
        return false
      end
    end
  end

  def prms(bind,*args)
    Params.new(bind,*args)
  end

  def x(*args)
    a,b = nil,nil
    case args.to_p(binding)
    when P[] then p []
    when P[:a] then p [a]
    when P[:a,:b] then p [a,b]
    else
      puts "don't know"
    end
  end

  x
  x(1)
  x(1,2)
  x(1,2,3)