From: Dave Thomas <Dave@...>
Date: 2002-02-14T03:44:13+09:00
Subject: Re: qualms about respond_to? idiom

Paul Brannan <paul@atdesk.com> writes:

> For builtins, I think this is justifiable, because Matz can just say
> "this is what this method name means; if you use that name to mean
> something else, then too bad for you."  But library writers generally
> don't have that luxury; if two library writers happen to pick the same
> name for two methods that do similar but different things, then that is
> a problem.  An object that has a method "foo" might work with library A,
> but not with library B, just because of the way "foo" is written to
> work.  This may not be obvious, though, to someone who is simply
> browsing the code.

That's where 'implements' comes in.

  class Tag
    implements Stackable

  end

it's both a flag and a check.


Dave