From: Daniel Colascione <dancol@dancol.org>
To: Paul Eggert <eggert@cs.ucla.edu>, Eli Zaretskii <eliz@gnu.org>,
Tom Tromey <tom@tromey.com>
Cc: aurelien.aptel+emacs@gmail.com, p.stephani2@gmail.com,
tzz@lifelogs.com, emacs-devel@gnu.org
Subject: Re: Dynamic modules: emacs-module.c and signaling errors
Date: Wed, 25 Nov 2015 01:11:16 -0800 [thread overview]
Message-ID: <56557B34.6090802@dancol.org> (raw)
In-Reply-To: <56557666.9080408@dancol.org>
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On 11/25/2015 12:50 AM, Daniel Colascione wrote:
> On 11/25/2015 12:24 AM, Paul Eggert wrote:
>> Daniel Colascione wrote:
>>> You could argue that file descriptors are basic. They're just handles to
>>> bits of kernel memory, right?
>>
>> I'm not making that argument. I am arguing that memory allocation is
>> basic, though. It really is. It happens *all the time* in the C code
>> inside Emacs, and it's almost surely going to happen all the time in
>> module code as well. It should be easy, not a pain.
>
> Modules in C already have to handle checking for failures of their
> internal allocations. What makes checking for failures of Emacs-side
> allocations so much worse?
>
> There are ways of making working with Lisp easier while preserving
> robustness.
Another option for making the Emacs API more ergonomic might be to
define most functions to do nothing if we have non-local control flow
pending, even on otherwise-invalid inputs. (That's opposed to making
emacs_env calls with pending non-local control into a programming
error.) That way, you'd be able to write something like this...
int64_t vplus1 = env->extract_integer(env, env->eval_fmt(env, "(1+ blah
%v)", v));
if (env->error_p()) {
return NULL;
}
... and preserve whatever went wrong inside eval_fmt, not abort or raise
some generic "invalid call to extract_integer" error.
I'm not sure that this scheme is a good idea, but it does make for
shorter code while still allowing us to propagate errors from any spot
inside Emacs.
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next prev parent reply other threads:[~2015-11-25 9:11 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-24 19:41 Dynamic modules: emacs-module.c and signaling errors Eli Zaretskii
2015-11-24 19:45 ` Eli Zaretskii
2015-11-24 20:12 ` Tom Tromey
2015-11-24 20:49 ` Eli Zaretskii
2015-11-24 21:34 ` Paul Eggert
2015-11-24 21:55 ` Daniel Colascione
2015-11-25 6:52 ` Paul Eggert
2015-11-25 7:03 ` Daniel Colascione
2015-11-25 7:14 ` Paul Eggert
2015-11-25 7:18 ` Daniel Colascione
2015-11-25 7:23 ` Paul Eggert
2015-11-25 7:25 ` Daniel Colascione
2015-11-25 7:49 ` Paul Eggert
2015-11-25 7:52 ` Daniel Colascione
2015-11-25 7:58 ` Paul Eggert
2015-11-25 8:12 ` Daniel Colascione
2015-11-25 8:24 ` Paul Eggert
2015-11-25 8:50 ` Daniel Colascione
2015-11-25 9:11 ` Daniel Colascione [this message]
2015-11-25 18:19 ` Eli Zaretskii
2015-11-25 18:26 ` Philipp Stephani
2015-11-25 19:19 ` Eli Zaretskii
2015-11-25 21:52 ` Philipp Stephani
2015-11-25 17:34 ` Paul Eggert
2015-11-24 22:21 ` Tom Tromey
2015-11-25 6:55 ` Paul Eggert
2015-11-25 17:30 ` Eli Zaretskii
2015-11-25 17:34 ` Paul Eggert
2015-11-25 21:23 ` Stefan Monnier
2015-11-26 15:42 ` Eli Zaretskii
2015-11-26 16:36 ` Stefan Monnier
2015-11-26 17:08 ` Eli Zaretskii
2015-11-26 19:28 ` Stefan Monnier
2015-11-26 19:34 ` Eli Zaretskii
2015-11-26 20:11 ` Stefan Monnier
2015-11-26 20:19 ` Eli Zaretskii
2015-11-26 21:20 ` Paul Eggert
2015-11-26 22:29 ` Philipp Stephani
2015-11-26 22:33 ` Philipp Stephani
2015-11-27 1:06 ` Stefan Monnier
2015-11-27 1:10 ` Daniel Colascione
2015-11-27 15:06 ` Stefan Monnier
2015-11-27 8:12 ` Eli Zaretskii
2015-11-27 9:11 ` Eli Zaretskii
2015-11-27 12:25 ` Aurélien Aptel
2015-11-27 14:44 ` Eli Zaretskii
2015-11-28 23:31 ` Paul Eggert
2015-11-27 1:21 ` Stefan Monnier
2015-11-27 8:26 ` Eli Zaretskii
2015-11-27 15:15 ` Stefan Monnier
2015-11-27 15:57 ` Eli Zaretskii
2015-11-27 16:29 ` Stefan Monnier
2015-11-27 17:38 ` Eli Zaretskii
2015-11-27 17:54 ` Stefan Monnier
2015-11-25 18:10 ` Tom Tromey
2015-11-25 18:15 ` Eli Zaretskii
2015-11-25 18:09 ` Philipp Stephani
2015-11-25 21:19 ` Stefan Monnier
2015-11-26 15:41 ` Eli Zaretskii
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