From: Dumaiu <Dymaio@...>
Date: 2006-07-26T14:10:04+09:00
Subject: Re: I'll have the duck!

7rans wrote:
...
>
> Well, besides the fact that all code is the implementation of a way of
> thinking, have you considered that you may be restricting the concept
> arbitrarily? You say DuckTyping is like ElegantWay, and yet I was able
> to use DuckType in psuedo-code in a meaningful way. I'd like to see you
> do the same with ElegantWay. If what you say is true, how is that
> possible?
>
... # yadda-yadda
>

A valid semantic point--'ElegantWay' isn't a one hundred per-cent fit
for a likeness; but it made me laugh, and it's the sort of example I
was trying to think of but couldn't.  Still, I am becoming increasingly
convinced that Mr. Black is right and duck typing cannot effectively be
modularized.  To recap: Duck typing is the near absence of type
checking in the Ruby core language.  It's a consequence of Ruby's
completely dynamic nature and the lack of distinction between method
definition and method call.  I think Dave Thomas called attention to
and named it because its appearance was almost accidental and it was
interesting enough to deserve a head-on approach, or at least
consideration of one.  But conceptually it's still an absence of
something (type validation)--a vacancy.  A 'TypeChecking' module might
be useable, but one for duck typing would be a 'NoTypeChecking' module,
i.e., empty.  You'd be trying to automate the act of leaving something
undone.  Actually, it makes me think of the 'Acme::Don't' module on
CPAN.
	The elimination of any reliance on class hierarchies really would
leave you with a prototype-based model.