On 27 Dec 2003 12:35:56 -0800, Thomas Bushnell, BSG <xxxxxx@becket.net> wrote:

> felix <xxxxxx@call-with-current-continuation.org> writes:
>
>> Exactly for that reason I propose to simplify the interface, and
>> to remove space for dirty tricks and to specify the meaning of the
>> forms rigorously.
>
> I am aghast that you think taking the address of a function is a
> "dirty trick"--especially since you are talking to a group of Scheme
> programmers!  Good grief.

Oh, come on.

>
> What *is* a dirty trick, and I am, I think, rightly worried about, is
> the dirty tricks that *implementors* play when you tell them to do
> things with a macro.  Functions are *far* more predictable than
> macros; they have a single well-defined semantics.  C macros can be
> tricky to write correctly.

You, as a user, don't have to write that macro. The dirty tricks
that implementors have to play, when trying to conform to this SRFI,
might be unavoidable.

>
> I don't believe you simplify *anything* by saying "you can do this
> with a macro if you like".  In practice, that is done in C standards
> precisely when you want to give implementors weird flexibility.  Look
> at, for example, the way that errno is allowed to be a macro in C, and
> why.

It looks like you never designed and implemented a Scheme FFI.
That flexibility on the implementors side is important. *Especially*
if portability is required.

>
> Moreover, you still will have people doing things like:
>
> #if defined (foo)
> do it where foo is a macre
> #else
> take the address of foo
> #endif
>

People will do all sorts of weird things. So what?

cheers,
felix