From: Kristof Bastiaensen <kristof@...>
Date: 2004-06-06T21:38:49+09:00
Subject: Re: How to ducktype a Hash?

On Sun, 06 Jun 2004 14:47:31 +0900, Sean O'Dell wrote:

> One test I can to really solve this problem is to create artificial tags
> for Hashes, my objects and any other objects that get created either by
> me or someone else as Hashes.  That solution will work, but my complaint
> is that it feels like such a kludge.  My problem is solved though -- I
> have several choices now.  I just wish Ruby did this already.  I am
> getting bit by little stupid things that are hard to catch, and my
> growing project is now starting to feel REALLY unstable.  I never get
> that feeling with C++, so I guess I should stop trying to use Ruby for
> these larger projects.  This one though, it started so nicely and
> fast...but now, it feels sort of kludgy and I don't have a feeling of
> confidence about its ability to either perform properly, or at least
> report errors that I consider errors.  Since there is no typing
> mechanism at all, I can't tell Ruby "hey, anything but a hash-like
> object here is an error."
> 
> 

Hm, just an idea, but perhaps is tagging not such an ugly solution?
You could create a dummy module Hashlike, include it in your hashlike
classes, and test with
  obj.is_a? Hashlike or obj.is_a? Hash

I guess it would work like interfaces in Java.

Kristof Bastiaensen