I'm confused about an eval-when in cl-info.lisp with GCL

On Fri, 2004-07-23 at 12:00, Raymond Toy wrote:
> >>>>> "James" == James Amundson <amundson@users.sourceforge.net> writes:
> 
>     James> I'm confused about some behavior I see in cl-info.lisp under GCL.
>     James> cl-info.lisp contains the following snippet:
>     James> ----------------------------------------------------------------
>     James> (eval-when (compile eval)
>     James>   (defmacro while (test &body body)
>     James>     `(loop while ,test do ,@ body))
>     James>   #+nil
>     James>   (defmacro f (op x y)
>     James>     `(,op (the fixnum ,x) (the fixnum ,y))))
>     James> ----------------------------------------------------------------
> 
> Does changing it to (compile load eval) make a difference?

Yes, that solves the problem. I thought of that, but for some reason I
didn't try it. I often find eval-when confusing.
 
> Is nregex sufficiently fast with gcl on a moderately slow PC?  nregex
> calls the compiler at runtime, and gcl has one of the slowest
> compilers out there.
> 
> When I tested this long ago, Clisp's relative slowness in regex
> matching was compensated for by its very fast compiler.  CMUCL ran the
> matcher quite fast, but compiling the regex was rather slow.
> However CMUCL was (just!) fast enough on a 300 MHz sparc that it
> wasn't too annoying.  Clisp was essentially instantaneous on that
> same sparc.

Ah. Thanks for reminding me about the speed issue. As I recall, I was
the one pushing for a solution that was fast enough on all lisps. The
current implementation I have would probably be irritatingly slow on a
slow machine. I also have to turn off compilation messages in order to
avoid making a big mess on the screen.

I just tried a simple solution: I #-gcl'd the definition of
string-match. GCL has a built-in version of string-match. I think that's
by far the simplest solution.

> Perhaps nregex should be replaced with cl-ppcre, which is known to run
> very fast with clisp and cmucl.  Don't know about gcl.  (But not for
> the imminent release, of course.)

I was thinking of that, too. If it's just for the info implementation, I
wouldn't think it would be worth the effort. However, it might be useful
to make regular expressions available at the maxima level. In that case,
I think cl-ppcre would be the way to go.

--Jim

P.S. I'm glad I asked. Your (Ray's) and Richard's comments have lead me
to a simpler and more robust implementation than I had when I started.