From: Paul Eggert <eggert@cs.ucla.edu>
To: Eli Zaretskii <eliz@gnu.org>
Cc: p.stephani2@gmail.com, emacs-devel@gnu.org
Subject: Re: JSON/YAML/TOML/etc. parsing performance
Date: Wed, 4 Oct 2017 14:24:59 -0700 [thread overview]
Message-ID: <21b0ba97-ed49-43ae-e86f-63fba762353a@cs.ucla.edu> (raw)
In-Reply-To: <83poa2ya8j.fsf@gnu.org>
On 10/04/2017 12:38 PM, Eli Zaretskii wrote:
> if we did use size_t for the arguments which can clearly only be
> non-negative, the problems which we are discussing would not have
> happened
Sure, but we would also have worse problems, as size_t is inherently
more error-prone. ptrdiff_t overflows are reliably diagnosed when Emacs
is compiled with suitable GCC compiler options. size_t overflows cannot
be diagnosed, are all too common, and can cause serious trouble.
The Emacs internals occasionally use size_t because underlying
primitives like 'malloc' do, so we do make some exceptions. Perhaps
there should be an exception here, for convenience with the JSON
library. The code snippets I've seen so far in this thread are not
enough context to judge whether an exception would be helpful in this
case. Generally speaking, though, unsigned types should be avoided
because they are more error-prone. This has long been the style in Emacs
internals, and it's served us well.
(Ironically, just last week I was telling beginning students to beware
unsigned types, with (0u < -1) as an example....)
next prev parent reply other threads:[~2017-10-04 21:24 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-16 15:54 JSON/YAML/TOML/etc. parsing performance Ted Zlatanov
2017-09-16 16:02 ` Mark Oteiza
2017-09-17 0:02 ` Richard Stallman
2017-09-17 3:13 ` Mark Oteiza
2017-09-18 0:00 ` Richard Stallman
2017-09-17 0:02 ` Richard Stallman
2017-09-18 13:46 ` Ted Zlatanov
2017-09-17 18:46 ` Philipp Stephani
2017-09-17 19:05 ` Eli Zaretskii
2017-09-17 20:27 ` Philipp Stephani
2017-09-17 22:41 ` Mark Oteiza
2017-09-18 13:53 ` Ted Zlatanov
2017-09-17 21:17 ` Speed of Elisp (was: JSON/YAML/TOML/etc. parsing performance) Stefan Monnier
2017-09-18 13:26 ` JSON/YAML/TOML/etc. parsing performance Philipp Stephani
2017-09-18 13:58 ` Mark Oteiza
2017-09-18 14:14 ` Philipp Stephani
2017-09-18 14:28 ` Mark Oteiza
2017-09-18 14:36 ` Philipp Stephani
2017-09-18 15:02 ` Eli Zaretskii
2017-09-18 16:14 ` Philipp Stephani
2017-09-18 17:33 ` Eli Zaretskii
2017-09-18 19:57 ` Thien-Thi Nguyen
2017-09-18 14:57 ` Eli Zaretskii
2017-09-18 15:07 ` Mark Oteiza
2017-09-18 15:51 ` Eli Zaretskii
2017-09-18 16:22 ` Philipp Stephani
2017-09-18 18:08 ` Eli Zaretskii
2017-09-19 19:32 ` Richard Stallman
2017-09-18 17:26 ` Glenn Morris
2017-09-18 18:16 ` Eli Zaretskii
2017-09-18 16:08 ` Philipp Stephani
2017-09-19 8:18 ` Philipp Stephani
2017-09-19 19:09 ` Eli Zaretskii
2017-09-28 21:19 ` Philipp Stephani
2017-09-28 21:27 ` Stefan Monnier
2017-09-29 19:55 ` Eli Zaretskii
2017-09-30 22:02 ` Philipp Stephani
2017-10-01 18:06 ` Eli Zaretskii
2017-10-03 12:26 ` Philipp Stephani
2017-10-03 15:31 ` Eli Zaretskii
2017-10-03 15:52 ` Philipp Stephani
2017-10-03 16:26 ` Eli Zaretskii
2017-10-03 17:10 ` Eli Zaretskii
2017-10-03 18:37 ` Philipp Stephani
2017-10-03 20:52 ` Paul Eggert
2017-10-04 5:33 ` Eli Zaretskii
2017-10-04 6:41 ` Paul Eggert
2017-10-04 8:03 ` Eli Zaretskii
2017-10-04 17:51 ` Paul Eggert
2017-10-04 19:38 ` Eli Zaretskii
2017-10-04 21:24 ` Paul Eggert [this message]
2017-10-05 1:48 ` Paul Eggert
2017-10-05 7:14 ` Eli Zaretskii
2017-10-08 22:52 ` Philipp Stephani
2017-10-09 5:54 ` Paul Eggert
2017-10-29 20:48 ` Philipp Stephani
2017-10-09 6:38 ` Eli Zaretskii
2017-10-05 7:12 ` Eli Zaretskii
2017-10-06 1:58 ` Paul Eggert
2017-10-06 7:40 ` Eli Zaretskii
2017-10-06 19:36 ` Paul Eggert
2017-10-06 21:03 ` Eli Zaretskii
2017-10-08 23:09 ` Philipp Stephani
2017-10-09 6:19 ` Paul Eggert
2017-10-29 20:48 ` Philipp Stephani
2017-10-29 22:49 ` Philipp Stephani
2017-12-09 23:05 ` Philipp Stephani
2017-12-10 7:08 ` Eli Zaretskii
2017-12-10 13:26 ` Philipp Stephani
2017-12-10 13:32 ` Ted Zlatanov
2017-10-08 23:04 ` Philipp Stephani
2017-10-09 6:47 ` Eli Zaretskii
2017-10-08 17:58 ` Philipp Stephani
2017-10-08 18:42 ` Eli Zaretskii
2017-10-08 23:14 ` Philipp Stephani
2017-10-09 6:53 ` Eli Zaretskii
2017-10-29 20:41 ` Philipp Stephani
2017-10-09 6:22 ` Paul Eggert
2017-10-01 18:38 ` Eli Zaretskii
2017-10-03 12:12 ` Philipp Stephani
2017-10-03 14:54 ` Eli Zaretskii
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