* labels usage
@ 2012-06-12 6:53 Katsumi Yamaoka
2012-06-12 7:25 ` Andreas Schwab
2012-06-12 13:07 ` Stefan Monnier
0 siblings, 2 replies; 4+ messages in thread
From: Katsumi Yamaoka @ 2012-06-12 6:53 UTC (permalink / raw)
To: emacs-devel; +Cc: emacs-w3m
Hi,
Is this a wrong usage?
(let (fn)
(labels ((fx (arg) arg))
(setq fn 'fx))
(funcall fn 99))
It worked until cl changed. Now this labels form is expanded into:
(progn
(defvar --cl---cl-fx----)
(let ((--cl---cl-fx---- nil))
(progn (set '--cl---cl-fx---- #'(lambda (arg) arg))
(setq fn 'fx))))
Whereas it was:
(let ((--cl---cl-var--86211-- nil))
(progn (set '--cl---cl-var--86211-- #'(lambda (arg) arg))
(setq fn (symbol-value '--cl---cl-var--86211--))))
Did we get to have no way to access the function definition, that
a labels form generates, in the outside of the labels form?
(If so, we have a solution; we have to simply replace labels with
let in such a Lisp code, i.e., emacs-w3m.)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: labels usage
2012-06-12 6:53 labels usage Katsumi Yamaoka
@ 2012-06-12 7:25 ` Andreas Schwab
2012-06-12 7:48 ` Katsumi Yamaoka
2012-06-12 13:07 ` Stefan Monnier
1 sibling, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2012-06-12 7:25 UTC (permalink / raw)
To: Katsumi Yamaoka; +Cc: emacs-w3m, emacs-devel
Katsumi Yamaoka <yamaoka@jpl.org> writes:
> Hi,
>
> Is this a wrong usage?
>
> (let (fn)
> (labels ((fx (arg) arg))
> (setq fn 'fx))
> (funcall fn 99))
You should use #'fx instead.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: labels usage
2012-06-12 7:25 ` Andreas Schwab
@ 2012-06-12 7:48 ` Katsumi Yamaoka
0 siblings, 0 replies; 4+ messages in thread
From: Katsumi Yamaoka @ 2012-06-12 7:48 UTC (permalink / raw)
To: schwab; +Cc: emacs-w3m, emacs-devel
In [emacs-w3m : No.11847] Andreas Schwab wrote:
> Katsumi Yamaoka <yamaoka@jpl.org> writes:
>> Is this a wrong usage?
>>
>> (let (fn)
>> (labels ((fx (arg) arg))
>> (setq fn 'fx))
>> (funcall fn 99))
> You should use #'fx instead.
Ok, we *should* use #' from now on. This was what Michael Heerdegen
wrote in the emacs-w3m list a while ago. Maybe it didn't go well
when I tried it was I forgot to build emacs-w3m from scratch. I'll
try it again. Thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: labels usage
2012-06-12 6:53 labels usage Katsumi Yamaoka
2012-06-12 7:25 ` Andreas Schwab
@ 2012-06-12 13:07 ` Stefan Monnier
1 sibling, 0 replies; 4+ messages in thread
From: Stefan Monnier @ 2012-06-12 13:07 UTC (permalink / raw)
To: Katsumi Yamaoka; +Cc: emacs-w3m, emacs-devel
> (labels ((fx (arg) arg))
> (setq fn 'fx))
'fx evaluates to the *symbol* `fx', not the *function* `fx'. In Elisp
until Emacs-24, you can use pretty much interchangeably a function and
the symbol to which it is bound, but with lexical scoping this is not
true any more. CL's `labels' used to follow the "Elisp tradition" and
looked inside `quote' to turn that symbol into a reference to the
locally defined function. But that was fundamentally a bug.
Stefan
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-06-12 13:07 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2012-06-12 6:53 labels usage Katsumi Yamaoka
2012-06-12 7:25 ` Andreas Schwab
2012-06-12 7:48 ` Katsumi Yamaoka
2012-06-12 13:07 ` Stefan Monnier
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