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Date: Tue, 23 Feb 2021 23:26:56 -0500
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Message-ID: <8CD7D960-51FA-45FE-B88F-2A18BA768DA4@newclarity.net>
Subject: Re: [PHP-DEV] Inline conditional that returns null if falsy
From: mike@newclarity.net (Mike Schinkel)

> On Feb 23, 2021, at 2:05 PM, Rowan Tommins <rowan.collins@gmail.com> =
wrote:
>=20
> On 23/02/2021 18:41, Albert Casademont wrote:
>> Sure, it's not a big deal having to write the ": null" but it doesn't =
add
>> any value
>=20
>=20
> On the contrary, it adds an important piece of information: that the =
default value is "null", rather than "false", or "0", or "new =
EmptyValue()".
> For instance, it doesn't seem at all obvious to me that this code =
should produce a null:
>=20
> $items =3D [];
> $itemCount =3D $items ? count($items);
>=20
> I might be more convinced that "null" is the "natural" value if the =
left-hand operand was only checked against null, not "falsiness": in =
that case, you can read it as "if it's null, leave it alone". I'd still =
be inclined towards "too specific to use up more syntax", though.

If you look at it from a software engineering perspective =E2=80=94 =
which is how I assume most on this thread have been looking at it =E2=80=94=
 being more explicit in the code is probably a better practice than =
saving a few keystrokes.

OTOH, if you view it from the perspective of a *templating* language =E2=80=
=94 which is what PHP was initially created to be, for the web =E2=80=94 =
then the reduction in visual noise from omitting ": null" would be a =
nice plus. And in the case of templating, the distinction between null =
vs. false vs. "" would be completely moot.

Repeating code similar to that from the message sent by David Rodrigues =
you can see that eliminating the ": null" is less noisy:

    <div class=3D"user <?php user ? 'online' : null ?>">...</div>
    <div class=3D"user <?php user ? 'online' ?>">...</div>

Although one  ":null" eliminated is not that significant, PHP templates =
for generating HTML are notorious for having conditionals littered =
throughout, with tens if not hundreds of cases per file.  So being able =
to drop the ":null" would be a really nice addition for templating.

To emphasize this feature address templating use-cases one might argue =
that dropping the "or" case of the trinary might only be supported when =
between single-line "<?php" and "?>" delimiters.=20

-Mike

P.S. Of course making it work differently between single-line delimiters =
and elsewhere would create inconsistency in the language so I probably =
would not actually argue that, I was just trying to make a rhetorical =
point.