From: Sean O'Dell <sean@...>
Date: 2004-06-08T01:53:51+09:00
Subject: Re: How to ducktype a Hash?

On Monday 07 June 2004 07:44, Austin Ziegler wrote:
> Gavin Sinclair [mailto:gsinclair@soyabean.com.au]:
> > What if a class tags itself as a "hash type" but an instance of it
> > redefines a method in a way that contradicts that type?
> >
> > I'm not being alarmist, but your messages have shown a great deal
> > of concern for knowing that an object does what it advertises. How
> > do you see the above scenario, then?
> >
> > I don't think your idea is a bad one, by the way.
>
> No, you're not being alarmist at all; even in statically typed
> languages, this is possible.
>
> I could define
>
>   class Foo < Doer
>   {
>     int does(int this) // reimplementation of Doer::does
>     {
>       // something with an undesired side-effect
>     }
>   }

That's my point about not tightly constraining the objects to their described 
interfaces.  Any programmer can come along and break anything if they want 
to.  In C++, Java...you can do it anywhere.  It's a moot point to try and 
force an object to do its job properly through language constructs.  That's 
what the programmers are there for.

	Sean O'Dell