From: "David A. Black" <dblack@...>
Date: 2005-01-26T21:31:29+09:00
Subject: Re: Injecting methods from one class into another.

Hi --

On Wed, 26 Jan 2005, E S wrote:

> Duck typing, essentially, means that, /in a particular context/, a
> given object has all the characteristics of a given type. For example,
> it might be enough for an object to implement [] and []= for it to be
> treated as a Hash in a certain context.

It's not exactly that it's being treated as a Hash -- it's more that,
*like* a Hash, it's being treated as an object that responds to [] and
[]=.  This is, perhaps, a subtle point, but I think it's key in
getting away from the class-based view.  All of the []/[]= objects
converge on the type that can only be described as "the type of
objects that respond to [] and []=".  In that sense, Hashes are just
one of infinitely many possible objects that exhibit the behaviors of
that type.


David

-- 
David A. Black
dblack@wobblini.net