Re: feature? or provided?

[Michael Livshin]

Dirk Herrmann <address@hidden> writes:

> On 6 Sep 2001, Michael Livshin wrote:
> 
> > I prefer `feature?', but that's maybe because I'm used to Emacs.
> > 
> > in Emacs, the way I see it, the idea of `provide' is to register a
> > feature, not to put a symbol in some predefined list.  it's about the
> > intent.  some features are never provided by calling `provide', they
> > just exist.
> 
> Well, the fact that 'provide' in guile just puts an object into a
> predefined list should be seen as an implementation detail.  I guess that
> semantically `provide╢ simply does what you want it to:  register a
> feature.  Or am I on the wrong track here?  What does Emacs do if you call
> 'provide' there?

before we get all wrapped up in semantics, just think what is more
natural to ask:

"does this car have sunroof?"       (a.k.a. `(feature? 'sunroof)')

or

"was sunroof built into this car?"  (a.k.a. `(provided? 'sunroof)')

sorry for car analogies. :)

-- 
Politics is non-euclidean.                           -- Robert Anton Wilson