From: ludo@gnu.org (Ludovic Courtès)
To: guile-devel@gnu.org
Subject: Re: eval-case and toplevel prohibitions
Date: Wed, 04 Mar 2009 09:48:32 +0100 [thread overview]
Message-ID: <87ab811xnj.fsf@gnu.org> (raw)
In-Reply-To: m3ocwjpmgw.fsf@pobox.com
Hello!
Andy Wingo <wingo@pobox.com> writes:
> So I was thinking: why do we have this fetish for prohibiting certain
> forms in a non-toplevel context? I am of a mind to replace eval-case
> with eval-when, which is actually more expressive, as it allows us to
> discriminate the different phases in non-toplevel contexts as well.
Could it be because `eval-case' expressions can evaluate to nothing,
which can be confusing in non-top-level contexts, e.g.,
(define (nothing)
(let ((foo (eval-case ((never-true) 'foo))))
foo))
Actually, this yields #<unspecified> in Guile-VM and #f in `master'.
The definition of `toplevel-env?' in there in quite sloppy...
Thanks,
Ludo'.
next prev parent reply other threads:[~2009-03-04 8:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-02 22:51 eval-case and toplevel prohibitions Andy Wingo
2009-03-03 7:31 ` Neil Jerram
2009-03-04 8:48 ` Ludovic Courtès [this message]
2009-03-06 10:56 ` Andy Wingo
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