From: Robert Klemme <bob.news@...>
Date: 2005-06-07T02:31:46+09:00
Subject: Re: making a duck

Eric Mahurin wrote:
> Regarding duck-typing... Is there an easy way make a "duck"?
> i.e. an object that responds to enough methods to be an
> acceptable argument to a certain methods.  For example, if I
> have a method that takes aString and uses the #size and #[i]
> methods, I could pass it something that looked just enough like
> a String to work:
>
> alphabet = Object.duck(:[],proc{|i|?a+i},:size,proc{26})

Why aren't you satisfied with

class Alpha
  def [](i) ?a+i end
  def size() 26 end
end
alphabet = Alpha.new

or

alphabet = Object.new
def alphabet.[](i) ?a+i end
def alphabet.size() 26 end

You can even squeeze that on one line if you feel the need for it.  I
mean, you don't generate those methods dynamically or get them from
somewhere else so why not just use the std approach?

Kind regards

    robert