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Date: Thu, 17 Sep 2015 14:46:50 +0100
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Subject: Re: [PHP-DEV] PHP 7.1 - Address PHPSadness #28?
From: rowan.collins@gmail.com (Rowan Collins)

Terry Cullen wrote on 17/09/2015 14:09:
> ​I agree that there is already ways around this issue, but I agree 
> with Bob that there is a hole that exists() would fill.  I my world 
> where PHP is the glue between JSON requests and database queries, ​ 
> exists() would be a function I'd use way more the array_key_exists(), 
> property_exists(), isset() and empty(). Further, in some scenarios 
> exists($foo->bar) would replace isset($foo) && is_object($foo) && 
> property_exists($foo, 'bar').

Yes, I've proposed elsewhere in this thread an exists() function (maybe 
under a different name) that is just syntax sugar for 
array_key_exists/property_exists, and raises an error if used with a 
bare variable.

This, it turns out, is exactly what Perl has: 
http://perldoc.perl.org/functions/exists.html

So you'd write exists($foo->bar), and the compiler would basically turn 
that into property_exists('bar', $foo) with appropriate suppression of 
notices in the same way isset() and empty() have.

There is still the problem that as this would be a language construct 
not a real function, there would be no way to polyfill it for older 
versions, so you couldn't use it until your code had a minimum version 
requirement of 7.1. A PECL extension *might* be able to backport it to 
older versions of PHP, but I doubt it would gain much adoption.

Regards,
-- 
Rowan Collins
[IMSoP]