xkcd-types.rb

#!/usr/bin/env ruby
# encoding: utf-8

class Fixnum
  alias_method :old_add, :+
  def +(other)
    if other.kind_of?(String)
      self.old_add(other.to_i).to_s
    elsif other == 2 && self == 2
      :DONE
    else
      self.old_add(other)
    end
  end

  alias_method :old_div, :/
  def /(other)
    if other == 0
      Float::NAN
    else
      self.old_div(other)
    end
  end

  def +@
    p :my_plus
    if self < 10
      self+10
    else
      self
    end
  end
end

class String
  alias_method :old_add, :+
  def +(other)
    if other.kind_of?(Array) && other.empty?
      "[#{self}]"
    else
      self.old_add(other)
    end
  end
end

module Kernel
  def range(*args)
    if args.size == 2
      f = args.shift.to_i
      l = args.shift.to_i
      a = (f..l).to_a
      1.upto(l/2 - 1).each do |i|
        a[i] = l-1
      end
      a
    elsif args.size == 1 && args[0] == " "
      ['"', "!", " ", "!", '"']
    else
      nil
    end
  end
end

p 2+"2"
p "2"+[]
p( 2/0 )
p( + 2 )
p( 2+2 )
p range(" ")
p range(1,5)