Re: [Chicken-users] How to use prelude?

[felix winkelmann]

On 5/28/06, Peter Bex <address@hidden> wrote:
> On Sun, May 28, 2006 at 12:31:14PM +0200, felix winkelmann wrote:
> > > Adding a quote in front of the define doesn't work either as that expands
> > > to (quote (define with-x #t))
> >
> > Try "'...'" (one pair of double-quotes for scheme, and one pair of single
> > quotes for the shell).
>
> It would be nice if you could document this in the manual.

Yes, there are a lot of things that should be mentioned there... ;-)

> > As Kon replied: register-feature! is the way. But that is at run-time,
> > of course.
> > To have it available at compile-time (I'm not 100% sure in what way you
> > want to use this), things are (as usual) a tiny little bit more complicated.
>
> Could you elaborate on how to do it?  I though cond-expand was compile-time.
> I guess I was wrong :)
>
> Anyway, what I want to do: I have a definition for a C function that only
> exists if Imlib2 is compiled without X.  So, if X is not found, I don't want
> a binding for that function.  I guess this has to be done compile time, since
> the function doesn't even exist, meaning the (foreign-lambda ...) can't be
> translated.

I think the best method is this: compile with or without "-feature XXX"
and then test in your code (at compile-time):

(cond-expand (XXX <code for XXX>) (else <code for not having XXX>))


cheers,
felix