From: Austin Ziegler <austin@...>
Date: 2003-09-13T07:38:09+09:00
Subject: Re: Mthod redefinition

Ferenc's code does, more or less, what Ryan Pavlik's StrongTyping module 
does.

However, with the exception of nil testing, you may feel more comfortable 
with duck typing.

For your simple case, it might be:

class Bar
  def foo(arg = nil)
    return "Who gives no input will get no output." if arg.nil?
    return "One gives me #{arg}."
  end
end

arg is, of course, not limited to integers at this point. The question would 
then become what is it that you wish to do with integers that you need the 
value? 

Duck typing is based mostly on realising what sort of operations you want to 
do with the object and testing for those operations, rather than testing for 
the class. As Dave is fond of saying: type and class aren't the same.

-austin
--
austin ziegler    * austin@halostatue.ca * Toronto, ON, Canada
software designer * pragmatic programmer * 2003.09.12
                                         * 18.29.32