Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:16664
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Message-ID: <9D.D2.20931.D8DDEA24@pb1.pair.com>
To: internals@lists.php.net
References: <5.1.0.14.2.20050603203711.028e9140@localhost><200506051859.53976.magnus@php.net> <6E.27.21296.C90E7A24@pb1.pair.com><38.CE.21296.BFD78A24@pb1.pair.com> <43.34.20931.17BEDA24@pb1.pair.com> <177634065.20050613225603@artweb-design.de>
Date: Tue, 14 Jun 2005 15:36:05 +0200
Lines: 101
Subject: Re: Re[2]: [PHP-DEV] PHP 5.1
From: r.korving@xit.nl ("Ron Korving")

No, ifsetor() is not possible in user land, because it generates notices,
and a php core function ifsetor() would not generate notices. That's really
the way it has to be.

Ron


"Sven Fuchs" <svenfuchs@artweb-design.de> wrote in message
news:177634065.20050613225603@artweb-design.de...
> Why isn't is possible in userland? Is there any problem with using
> this?
>
> function ifsetor(&$var, $default = null) {
>     return isset($var) ? $var : $default;
> }
>
> echo ifsetor($a, 'foo');
> echo $a, $b;
> echo ifsetor($a, 'foo');
> echo isset($a) ? 'is set' : 'not set';
>
> expected result:
>
> foo
> Notice: Undefined variable: a in [...]
> Notice: Undefined variable: b in [...]
> foo
> not set
>
> actual result:
>
> foo
> Notice: Undefined variable: b in [...]
> foo
> not set
>
> php does not issue a notice on using $a after having called ifsetor()
> once. But further calls to isset() and ifsetor() keep returning the
> expected results.
>
> I'd assume, the missing notice is rather a bug than a feature. So
> ifsetor() is possible in userland.
>
> --
> Sven
>
>
> > If it were possible at all to make a function accept unset variables
without
> > generating a notice, I think ifsetor() shouldn't even be implemented.
People
> > could then have the freedom to create such functions themselves. But
> > unfortunately, it doesn't seem to be possible, unless you'd suppress
every
> > function call with a @, which I don't think is the way to go in this
case.
>
> > So if it would be possible somehow to create your own isset()-like
functions
> > in PHP-code, I'd say implement something that would make that possible,
and
> > ingore the whole ifsetor() discussion from that moment on. People would
be
> > free to write whatever function they'd prefer.
>
> > Ron
>
>
> > ""Sara Golemon"" <pollita@php.net> wrote in message
> > news:38.CE.21296.BFD78A24@pb1.pair.com...
> >> > > What about ifsetor for 5.1 ?
> >> >
> >> > Would anybody be interested in a parameter for ifsetor() that would
> > treat
> >> > isset() as !empty() or an alternative function that achieves this? I
> > know
> >> > I'd love to see that. I use empty() a lot more than isset().
> >> >
> >> In the interrest of KISS, I'd leave the emptiness concept out of the
> >> picture.  Unlike isset-ness, an emptiness coalesce *can* be done in
> >> userspace:
> >>
> >> function firstNotEmpty() {
> >>     $vars = func_get_args();
> >>     foreach($vars as $var)
> >>         if (!empty($var)) return $var;
> >>     return NULL;
> >> }
> >>
> >> There's enough....contention over the undeniably useful and
> >> not-implementable-in-userspace parts of this thread that it's not worth
> >> muddling it up with things that are a simple matter to do in userspace.
> > It
> >> doesn't matter that notempty() and ifsetor() could easily be
implemented
> > by
> >> the same opcode (just like isset/empty are).
> >>
> >> -Sara