From: Florian Gross <flgr@...>
Date: 2005-03-27T00:04:48+09:00
Subject: Re: Hash::MixIn and Python style Object#dict

gabriele renzi wrote:

> But I wonder: why both you and florian considered the need to have 
> contracts for this mixable things?
> I used to love this, and being scared from mixins like Enumerable wich 
> do not have checks, but now I feel this is very non-rubyish.

It's basically for letting your users check at the time they do 'include 
Hash::MixIn' (in this case it would be 'fulfills Hash::Contract') 
whether they have implemented all the prerequisites correctly. For 
Enumerable and so on that makes not too much as the only preconditions 
are providing an .each method, but I think that this could in general be 
quite powerful.

I've also tried to switch away from Class-based typing entirely and to 
instead use unit testing for defining contracts. I'm not sure of the 
exact implications, but it was nice to finally implement this idea that 
I had for so long. I've not fully explored all the possibilities though 
so expect to see changes and additions in the future.