From: dblack@...
Date: 2003-11-18T04:07:56+09:00
Subject: Re: Strong Typing (Re: Managing metadata about attribute types)

Hi --

On Mon, 17 Nov 2003, Thien Vuong wrote:

> - I'm very sure that the this object behaviour/or my need could be
> encapsulated fully in this method - so there is no good reason to create
> extra code to do needless things.
>
> This is valid and works much of the time, but does not scale into the
> argument that class/module checkin is an inferior/crutchy way to design.
> Once the needed object behaviour becomes more complex, class/module
> interface is needed to describe that behaviour (of course, respond_to
> combination/manipulation could do it too, but we would be trying to
> reinvent the wheel against a proven/established system already).

The system you're describing -- one-to-one, immutable mapping of
methods in a class with methods of which that class's instances are
capable -- is only proven and established in languages where it's
enforced, which don't include Ruby.  What you're saying is sort of
like saying: using a keyboard to generate musical notes is proven and
established, so let's add keyboards to violins.  (Actually it's more
like saying: let's play the violin by using its keyboard; to which I
say: what keyboard? :-)

> I was drawn to ruby because of the OO capability + extra dynamicity
> which added to the OO capablity - and it would be a shame to just
> embrace the dynamics only and drop the OO.

These things aren't at war with each other; it's a dynamic,
object-oriented language.  I'd advise against looking at the dynamism
of Ruby objects as "extra".  It's present from the ground up, and goes
absolutely straight to the heart of the "type != class" principle in
Ruby.


David

-- 
David Alan Black
home: dblack@wobblini.net        # New email address
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav