From: Filipp Gunbin <fgunbin@fastmail.fm>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: help-gnu-emacs@gnu.org
Subject: Re: What does "lacks a prefix" mean?
Date: Mon, 13 Jul 2015 15:26:14 +0300 [thread overview]
Message-ID: <m2bnfgw8ex.fsf@fastmail.fm> (raw)
In-Reply-To: <jwvd200q794.fsf-monnier+gmane.emacs.help@gnu.org> (Stefan Monnier's message of "Fri, 10 Jul 2015 13:04:30 -0400")
On 10/07/2015 13:04 -0400, Stefan Monnier wrote:
>>> let* says "I need variables which depend on each
>>> other" and if they're really not, that look strange.
>
> If let behaved like let* it wouldn't look strange to you. Many other
> functional languages dropped the "simultaneous let" and only kept the
> equivalent of let* (or even letrec).
But if 90% of users make the distinction and 10% of them don't it would
cause confusion. If everybody uses the same construct then it does not
matter.
letrec is nice :-)
>>> And probably it's a bit slower.
>
> Regarding efficiency, there's no clear winner between the two.
> It's basically irrelevant.
I meant that there could be an extra inner frame for each of the
bindings in let*, while only one in let. I don't have enough knowledge
of emacs lisp implementation to say for sure, that's why "probably" in
my comment.
>>> And non-parallelizable theoretically :)
>
> In practice neither is easily parallelizable anyway.
Is it because each of the value expression could modify something in the
environment?
> And the work needed to auto-convert a "let*" to a "let" when possible
> is trivial in comparison to what's needed to parallelize the code. So
> again, it's really irrelevant.
Ok, thanks.
Filipp
next prev parent reply other threads:[~2015-07-13 12:26 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-08 16:32 What does "lacks a prefix" mean? BobD
2015-07-08 16:45 ` Barry Margolin
2015-07-08 16:59 ` Vaidheeswaran C
2015-07-08 17:10 ` Vaidheeswaran C
2015-07-08 18:17 ` BobD
2015-07-08 18:21 ` Pascal J. Bourguignon
2015-07-08 18:45 ` BobD
2015-07-08 23:24 ` Emanuel Berg
2015-07-09 15:23 ` Filipp Gunbin
2015-07-09 22:32 ` Emanuel Berg
2015-07-10 17:04 ` Stefan Monnier
2015-07-11 22:42 ` Emanuel Berg
[not found] ` <mailman.6748.1436654668.904.help-gnu-emacs@gnu.org>
2015-07-11 23:58 ` Barry Margolin
2015-07-13 12:26 ` Filipp Gunbin [this message]
[not found] ` <mailman.6685.1436547891.904.help-gnu-emacs@gnu.org>
2015-07-10 18:27 ` Barry Margolin
[not found] ` <mailman.6612.1436455429.904.help-gnu-emacs@gnu.org>
2015-07-09 23:27 ` Barry Margolin
[not found] ` <mailman.6643.1436488423.904.help-gnu-emacs@gnu.org>
2015-07-10 0:49 ` Pascal J. Bourguignon
2015-07-10 5:04 ` Drew Adams
2015-07-10 14:42 ` Barry Margolin
[not found] ` <<barmar-2BC802.10421910072015@88-209-239-213.giganet.hu>
2015-07-10 14:53 ` Drew Adams
[not found] ` <<barmar-500871.19271109072015@88-209-239-213.giganet.hu>
2015-07-10 0:33 ` Drew Adams
[not found] ` <mailman.6590.1436397914.904.help-gnu-emacs@gnu.org>
2015-07-09 14:01 ` Barry Margolin
2015-07-09 14:10 ` Rusi
2015-07-09 22:27 ` Emanuel Berg
[not found] ` <mailman.6639.1436481016.904.help-gnu-emacs@gnu.org>
2015-07-10 3:10 ` Rusi
2015-07-10 16:00 ` Emanuel Berg
2015-07-09 22:19 ` Emanuel Berg
[not found] ` <<barmar-F23189.10014209072015@88-209-239-213.giganet.hu>
2015-07-09 15:33 ` Drew Adams
2015-07-12 1:47 ` Emanuel Berg
2015-07-12 16:59 ` Drew Adams
2015-07-13 0:46 ` Emanuel Berg
2015-07-13 7:26 ` Yuri Khan
2015-07-13 23:47 ` Emanuel Berg
2015-07-14 6:23 ` Yuri Khan
2015-07-14 21:58 ` Emanuel Berg
2015-07-19 0:59 ` Robert Thorpe
2015-07-28 0:24 ` Emanuel Berg
2015-07-30 1:40 ` Robert Thorpe
[not found] ` <mailman.7638.1438220428.904.help-gnu-emacs@gnu.org>
2015-07-30 2:49 ` Rusi
2015-07-30 2:53 ` Rusi
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