From: Stefan Monnier <monnier@iro.umontreal.ca>
To: emacs-devel@gnu.org
Subject: Re: `aset` on strings, changing the size in bytes
Date: Sat, 08 Sep 2018 18:09:41 -0400 [thread overview]
Message-ID: <jwvva7fmys9.fsf-monnier+gmane.emacs.devel@gnu.org> (raw)
In-Reply-To: 83k1nvso1o.fsf@gnu.org
>> The need for an indirection (a String_Object has to hold a pointer to an
>> sdata object rather than being able to keep its payload directly in the
>> Lisp_String object (using FLEXIBLE_ARRAY_MEMBER))
> Why is that a problem?
It slows down every string access, and increases the heap size of every
string (currently they're something like N bytes of payload plus
5 words where 2 of those 5 words are due to the extra indirection).
For a feature that's almost never used, I think it's pretty costly.
Stefan
next prev parent reply other threads:[~2018-09-08 22:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-07 19:52 `aset` on strings, changing the size in bytes Stefan Monnier
2018-09-07 21:33 ` Johan Bockgård
2018-09-07 23:12 ` Paul Eggert
2018-09-07 23:41 ` John Wiegley
2018-09-08 5:17 ` Richard Stallman
2018-09-08 6:34 ` Eli Zaretskii
2018-09-08 2:04 ` Stefan Monnier
2018-09-08 2:17 ` Paul Eggert
2018-09-08 6:41 ` Eli Zaretskii
2018-09-08 18:03 ` Stefan Monnier
2018-09-08 18:20 ` Eli Zaretskii
2018-09-08 18:36 ` Stefan Monnier
2018-09-08 20:59 ` Eli Zaretskii
2018-09-08 22:09 ` Stefan Monnier [this message]
2018-09-09 5:22 ` Eli Zaretskii
2018-09-10 0:18 ` Stefan Monnier
2018-09-09 6:07 ` Richard Stallman
2018-09-09 6:26 ` Eli Zaretskii
2018-09-09 14:44 ` Noam Postavsky
2018-09-09 15:17 ` Eli Zaretskii
2018-09-09 16:27 ` Noam Postavsky
2018-09-10 5:48 ` Richard Stallman
2018-09-10 3:03 ` Stefan Monnier
2018-10-16 21:05 ` Stefan Monnier
2018-09-10 5:47 ` Richard Stallman
2018-09-10 5:48 ` Richard Stallman
2018-09-10 3:02 ` Stefan Monnier
2018-09-08 6:03 ` Helmut Eller
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