From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Re: Doc strings starting with a line break
Date: Sun, 18 Sep 2016 11:58:23 -0400 [thread overview]
Message-ID: <jwvd1k1jjhd.fsf-monnier+gmane.emacs.devel@gnu.org> (raw)
In-Reply-To: CAPM58ogXOkqURAEtTpUFA3EV+YB2pWgG85WuFWHkKvCuZrtxaQ@mail.gmail.com
>> i am wondering what could be the reason for some doc strings
>> starting with a break line.
>> For instance, see `isearch-forward' or `looking-at-p'.
> The newline is escaped so it's not part of the docstring. For
> `looking-at-p' it allows the following line of code to fit into 80
> characters. For `isearch-forward' it seems unnecessary but it
> has been that way for 24 years. They do things differently
> there :)
There's a special hack in the Lisp reader which reads such strings as
the constant 0 (under some circumstances) so that we don't allocate
memory for those strings which will soon after be replaced by
a reference to some part of the DOC file (via Snarf-documentation).
This memory could/would be recovered by GC, so it wouldn't be completely
wasted, but it usually wouldn't be returned to the OS (IOW it would stay
in the free-list of Elisp's memory manager), so it would result in
a slightly larger bin/emacs executable and initial memory footprint
(unless we replace this current hack by some other mechanism, obviously).
Stefan
next prev parent reply other threads:[~2016-09-18 15:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-18 10:51 Doc strings starting with a line break Tino Calancha
2016-09-18 11:06 ` Richard Copley
2016-09-18 11:18 ` Tino Calancha
2016-09-18 15:58 ` Stefan Monnier [this message]
2016-09-18 16:59 ` Andreas Schwab
2016-09-19 1:06 ` Stefan Monnier
2016-09-18 12:27 ` Andreas Schwab
2016-09-18 12:29 ` Tino Calancha
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