Re: featurep

[Stefan Monnier]

> address@hidden (Kim F. Storm) writes:
> 
> > However, for a usage point of view, I don't really see why it
> > matters, and IMHO, using featurep will be _less_ intuitive.
> > For example, I think using
> > 
> >   (if (and (make-network-process :feature :family 'local)
> >            (make-network-process :feature :datagram t))
> 
> Having make-network-process doing something other than making a
> network process is not a more intuitive solution than featurep.

Agreed.  I also agree that `featurep' is not a perfect answer, tho.
Ideally, what I'd like is something like

        (featuredp '(make-network-process :family 'local))

where `featuredp' simply takes a function together with a set of
arguments and returns whether or not that call is "supported".
It would first check the fboundness of the function, the number of arguments
and all those things.

But I have no good idea how to go about implementing this thing, so
as a first step, I think that it should be good enough just to make
`make-network-process' fail when called with arguments requiring
unsupported features.  After all, it's generally the case that if
the feature is supported, then we do want to make the function call,
so we might as well call the function and see if it worked.


        Stefan