Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:69192
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: unknown (pb1.pair.com: domain chrislondon.co does not designate 74.125.82.44 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <012B9378-3C3A-4169-96D3-3B57D6C7A82C@seancoates.com>
References: <CAPwsocGni4kjJq9c5wr77ohPU+YX2=0O7EgahdH=p0=hH1H_fA@mail.gmail.com>
	<49D57F66323040FC9AE48244DAAF3771@gmail.com>
	<012B9378-3C3A-4169-96D3-3B57D6C7A82C@seancoates.com>
Date: Wed, 18 Sep 2013 07:57:44 -0600
Message-ID: <CAAjMSDNwmpFRpX4VTj-AoUYp2PWXioyQRE3o8eCvb8VzXsB9Hw@mail.gmail.com>
To: Sean Coates <sean@seancoates.com>
Cc: Leigh <leight@gmail.com>, "internals@lists.php.net" <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=047d7bb70cb04f018204e6a8d237
Subject: Re: [PHP-DEV] Re: Allowing is_* functions to accept multiple parameters
From: me@chrislondon.co (Chris London)

--047d7bb70cb04f018204e6a8d237
Content-Type: text/plain; charset=ISO-8859-1

I like the naming convention of are_*.  For me personally it isn't directly
intuitive that the multiple parameters of is_* would be compared with an &&
and not an ||.


On Wed, Sep 18, 2013 at 7:50 AM, Sean Coates <sean@seancoates.com> wrote:

> > i.e. is_null($a, $b, $c) would be the same as is_null($a) && is_null($b)
> > && is_null($c)
>
> Note that this would not be semantically equivalent in this form, even if
> `is_null()` did accept multiple parameters, because of the short-circuiting
> with `&&`:
>
> <?php
>
> function are_null() {
>         foreach (func_get_args() as $a) {
>                 if ($a !== null) {
>                         return false;
>                 }
>         }
>         return true;
> }
>
> function destroy_data() { echo "DESTROYING DATA\n"; }
>
> // old form: short-circuited; data is not destroyed
> if (is_null(null) && is_null(false) && is_null(destroy_data())) {
>         echo "All null.\n";
> } else {
>         echo "Not null.\n";
> }
>
> echo "----\n";
>
> // proposed form: no short-circuit; parameters are evaluated at call time
> and data is destroyed
> if (are_null(null, false, destroy_data())) {
>         echo "Still null.\n";
> } else {
>         echo "Still not null.\n";
> }
>
>

--047d7bb70cb04f018204e6a8d237--