From: Florian Gross <flgr@...>
Date: 2004-06-06T11:38:40+09:00
Subject: Re: How to ducktype a Hash?

Sean O'Dell wrote:

> No, it IS my problem.  My code quietly does some really undesired things when 
> non-hash-like objects get to this one point in code.  I hate this attitude 
> about typing.  I know you mean well, and it's been talked out to death, but I 
> don't buy the whole thing about "if it has the methods, it must be fine."  
> It's clearly NOT fine.  If an array or a string, both which have the [] 
> methods I need, get to this one place, I drop a whole branch of data being 
> passed around.  The ideal is to catch it as an error, and remedy the 
> situation by finding out how the data came in that way in the first place and 
> prevent it, or perhaps just detect it and perform some special case.  As it 
> is, I can't tell for sure when an object really DOES act like a hash.

I think what you're getting at is this:

Duck typing isn't really "quacks like a duck", but rather "quacks" in 
its current state.

Maybe it would be an interesting thing to be able to take a set of unit 
tests and dynamically run them on the Object that you're getting...?

Regards,
Florian Gross