From: Sean O'Dell <sean@...>
Date: 2004-06-08T01:39:55+09:00
Subject: Re: How to ducktype a Hash?

On Monday 07 June 2004 07:33, Vlad wrote:
> "Sean O'Dell" <sean@celsoft.com> wrote in message
> news:<200406041915.32644.sean@celsoft.com>...
>
> > In both cases, does that mean that the object has hash-like
> > functionality, or just that the object responds to those two methods?  Is
> > there some definition somewhere that says "it's a hash if it has these
> > methods?"  I actually have hash-like objects that DON'T respond to either
> > of those two methods, but it would be easy enough to add fake ones.  I
> > hate adding fake methods just to id a hash interface, it's a kludge.
> >
> > 	Sean O'Dell
>
> Guess, you will be happy if Ruby can do some like ...
>
> obj.respond_to?(Hash::[])
> or
> obj.respond_to?(Foo::[])

Yes, if obj.respond_to?(Hash::[]) can be called for non-Hash objects, and for 
objects that don't derive from Hash, but which implement hash-like 
functionality.  The semantics aren't important.  That method of interface 
checking would work as well as any.

	Sean O'Dell