Date: Mon, 31 Dec 2001 12:39:12 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org, Julian Elischer <julian@FreeBSD.org>, Greg Lehey <grog@FreeBSD.org> Subject: Re: cvs commit: src/share/man/man3 queue.3 Message-ID: <XFMail.011231123912.jhb@FreeBSD.org> In-Reply-To: <21051.1009706416@critter.freebsd.dk>
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On 30-Dec-01 Poul-Henning Kamp wrote:
> In message <20011230094936.K90696@monorchid.lemis.com>, Greg Lehey writes:
>>On Saturday, 29 December 2001 at 8:55:05 +0100, Poul-Henning Kamp wrote:
>>> In message <200112282200.fBSM0Rw61760@freefall.freebsd.org>, Julian
>>> Elischer wr
>>> ites:
>>>> julian 2001/12/28 14:00:27 PST
>>>>
>>>> Modified files:
>>>> share/man/man3 queue.3
>>>> Log:
>>>> Document some behaviour I'm depending on.
>>>> (TAILQ_FOREACH leaves the variable NULL if there were no more to do)
>>>
>>> I don't like this.
>>
>>Do you have a reason for not liking it?
>
> Yes, I don't like statements with weird sideeffects. If julian
> wants the sideeffect, he should not use a _FOREACH() macro to hide
> the internals of the loop.
>
> _FOREACH() is for the plain & simple traversal of a queue(3) stucture,
> anything more should explicitly state intent.
I would agree except for code like this:
TAILQ_FOREACH(p, &list, p_next)
if (some_test_on(p))
break;
if (p != NULL) {
/* Found one, now do something. */
}
You could work around this via a goto instead I suppose:
TAILQ_FOREACH(p, &list, p_next)
if (some_test_on(p))
goto found;
goto not_found
found:
/* Do something */
not_found:
But that's uglier IMO.
--
John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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