Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:99844
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.128.171 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <CAOe2Xe6vY2byZg0MSru=HftqBSwW_B_SsseN8L=pVi39LCccBA@mail.gmail.com>
References: <CAOe2Xe4j9dOa63wkG2gJxosH1fymWDB9C-zcXwDWGcB=Zw9w9g@mail.gmail.com>
 <E29279E7-D813-437B-BECB-E2612A6C86DE@gmail.com> <CAOe2Xe6vY2byZg0MSru=HftqBSwW_B_SsseN8L=pVi39LCccBA@mail.gmail.com>
Date: Tue, 11 Jul 2017 21:05:06 +0100
Message-ID: <CALtMV+NeLjPfdhGhW4idn9O-t+ZnPGwsXraeVWNW6qzNadRKVw@mail.gmail.com>
To: Mark Shust <mark@shust.com>
Cc: Rowan Collins <rowan.collins@gmail.com>, PHP internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary="001a114b56d64775df05541037b4"
Subject: Re: [PHP-DEV] array coalesce operator concept
From: aidantwoods@gmail.com (Aidan Woods)

--001a114b56d64775df05541037b4
Content-Type: text/plain; charset="UTF-8"

If you were willing to accept

```
foreach ($foo as $bar) if (is_array) {
...
}
```

as a solution, then you might as well use

```
if (is_array($foo)) foreach ($foo as $bar) {
...
}
```

I wonder if this could be better achieved by expanding what the error
suppression operator `@` can do? This entire behaviour seems more like an
error suppression action on `foreach` to me, otherwise should we consider
coalescing operators for other types/creating a more generic one?

Going back to the error suppression operator:

e.g. perhaps

```
foreach ($foo @as $bar) {
...
}
```

could prevent skip past execution of the entire foreach block if there is
an error using $foo as an array. So might make most sense to place the `@`
on `as`, IMO, but I guess arguments could be made to place it like
`@foreach ($foo as $bar)` or `foreach @($foo as $bar)`.


Regards,
Aidan

On 11 July 2017 at 20:06, Mark Shust <mark@shust.com> wrote:

> Thanks for the great feedback.
>
> Based on the last mindset on keyword syntax, this comes to mind, intended
> to be used similarly to the 'use' keyword when used within the context of a
> closure:
>
> foreach ($foo as $bar) if (is_array) {
> ...
> }
>
>
> I don't think this is a vast improvement over wrapping this within an
> is_array check, however it does avoid the additional nest/wrapping. I was
> hoping for something that reads a bit more concisely or with a bit more
> syntactical sugar than the above. I think this does read nicely though.
>
> Cheers,
> Mark
>
> On Tue, Jul 11, 2017 at 1:50 PM Rowan Collins <rowan.collins@gmail.com>
> wrote:
>
> > On 11 July 2017 16:02:18 BST, Mark Shust <mark@shust.com> wrote:
> > >For a syntactic
> > >sugar/improvement, this can be shorthand for executing the loop instead
> > >of
> > >wrapping the block within an is_array check:
> > >
> > >
> > ><?php
> > >
> > >$foo = "abc";
> > >
> > >foreach (??$foo as $bar) {
> > >
> > >  echo $bar;
> > >
> > >}
> >
> > Hi!
> >
> > I think there's definitely the start of a good idea here, but the syntax
> > you suggest doesn't read quite right. As has been pointed out, this
> differs
> > from existing features in two ways:
> >
> > - the special handling is for any non-iterable value, not just null or
> > empty/falsey values, for which you could use $foo??[] and $foo?:[]
> > respectively
> > - the handling is to skip the loop, not loop once assigning $bar to the
> > scalar value, as would happen with (array)$foo
> >
> > The challenge, then, is to come up with some syntax that somehow suggests
> > these rules. The "??" is too much like the null coalesce, which would be
> > misleading.
> >
> > The only idea that immediately comes to mind is a keyword:
> >
> > foreach ifarray ($foo as $bar) {
> >
> > I can't say I'm that keen on that syntax, but maybe it will inspire
> > someone else.
> >
> > Regards,
> >
> > --
> > Rowan Collins
> > [IMSoP]
> >
>

--001a114b56d64775df05541037b4--