* Re: [Emacs-diffs] master fbda511: Fix cps--gensym
[not found] ` <E1YsjhZ-0002a0-0n@vcs.savannah.gnu.org>
@ 2015-05-14 16:00 ` Stefan Monnier
2015-05-14 23:48 ` Leo Liu
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Monnier @ 2015-05-14 16:00 UTC (permalink / raw)
To: emacs-devel; +Cc: Leo Liu
> ;; Change this function to use `cl-gensym' if you want the generated
> ;; code to be easier to read and debug.
> ;; (cl-gensym (apply #'format fmt args))
> - `(make-symbol ,fmt))
> + `(make-symbol (format ,fmt . ,args)))
Why? As the comment above says, if you want the more readable names,
you should use the other line of code. The default one is aimed at
being more efficient (both cpu-use-wise and memory-use-wise),
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Emacs-diffs] master fbda511: Fix cps--gensym
2015-05-14 16:00 ` [Emacs-diffs] master fbda511: Fix cps--gensym Stefan Monnier
@ 2015-05-14 23:48 ` Leo Liu
2015-05-15 2:05 ` Stefan Monnier
0 siblings, 1 reply; 6+ messages in thread
From: Leo Liu @ 2015-05-14 23:48 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
On 2015-05-15 00:00 +0800, Stefan Monnier wrote:
> Why? As the comment above says, if you want the more readable names,
> you should use the other line of code. The default one is aimed at
> being more efficient (both cpu-use-wise and memory-use-wise),
I changed it because the expansion of iter-lambda etc. was difficult to
read. I don't understand the efficiency issue so the change may be a
mistake. Could you elaborate on what the issue is? Thanks.
Leo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master fbda511: Fix cps--gensym
2015-05-14 23:48 ` Leo Liu
@ 2015-05-15 2:05 ` Stefan Monnier
2015-05-15 4:42 ` Leo Liu
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Monnier @ 2015-05-15 2:05 UTC (permalink / raw)
To: Leo Liu; +Cc: emacs-devel
>> Why? As the comment above says, if you want the more readable names,
>> you should use the other line of code. The default one is aimed at
>> being more efficient (both cpu-use-wise and memory-use-wise),
> I changed it because the expansion of iter-lambda etc. was difficult to
> read.
Right, and as the comment say, when you want to read the expansion, you
should use the other code (the one that uses cl-gensym+format).
> I don't understand the efficiency issue so the change may be a
> mistake. Could you elaborate on what the issue is? Thanks.
format is already significantly more expensive than make-symbol, so
obviously, make-symbol + format will be even worse.
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [Emacs-diffs] master fbda511: Fix cps--gensym
2015-05-15 2:05 ` Stefan Monnier
@ 2015-05-15 4:42 ` Leo Liu
2015-05-15 18:19 ` Stefan Monnier
0 siblings, 1 reply; 6+ messages in thread
From: Leo Liu @ 2015-05-15 4:42 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
On 2015-05-15 10:05 +0800, Stefan Monnier wrote:
> format is already significantly more expensive than make-symbol, so
> obviously, make-symbol + format will be even worse.
OK but this doesn't impact runtime, right? All the hard work will be
done in compile time.
Leo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Emacs-diffs] master fbda511: Fix cps--gensym
2015-05-15 4:42 ` Leo Liu
@ 2015-05-15 18:19 ` Stefan Monnier
2015-05-16 1:07 ` Leo Liu
0 siblings, 1 reply; 6+ messages in thread
From: Stefan Monnier @ 2015-05-15 18:19 UTC (permalink / raw)
To: Leo Liu; +Cc: emacs-devel
>> format is already significantly more expensive than make-symbol, so
>> obviously, make-symbol + format will be even worse.
> OK but this doesn't impact runtime, right? All the hard work will be
> done in compile time.
No, it only impacts the macroexpansion time/space. But the point is
that if you don't care about that, then you should use the
cl-gensym version. The make-symbol version is the "fast path", so making
it fat&slow makes no sense.
Stefan
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-05-16 1:07 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20150514032048.9882.50538@vcs.savannah.gnu.org>
[not found] ` <E1YsjhZ-0002a0-0n@vcs.savannah.gnu.org>
2015-05-14 16:00 ` [Emacs-diffs] master fbda511: Fix cps--gensym Stefan Monnier
2015-05-14 23:48 ` Leo Liu
2015-05-15 2:05 ` Stefan Monnier
2015-05-15 4:42 ` Leo Liu
2015-05-15 18:19 ` Stefan Monnier
2015-05-16 1:07 ` Leo Liu
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).