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Date: Sat, 28 Mar 2026 18:31:06 +0000
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Subject: Re: [PHP-DEV] [RFC] Four Pragmatic Directions for PHP: Simplicity,
 Arrays, Performance, Concurrency
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From: imsop.php@rwec.co.uk ("Rowan Tommins [IMSoP]")

On 27/03/2026 15:19, Alex Rock wrote:
>
> In that case, maybe reuse something similar to the null-safe operator ?
>
> Something like `$foo['bar']?`
>

I think even if you could make it work in the parser, it would be hard 
to make that read well with the ternary operator:

$foo['a'] ? ['b'] ? ['c'] : ['d'];


>     return $foo['one']?['two'];

Looking at that, it's not obvious to me whether it's 'one' or 'two' 
which is optional.

return $foo['one']  ?['two'];
return $foo['one']?  ['two'];


> And here it gets interesting:
>
>     return $foo['one']['two']?['three'];
>     // is roughly equivalent to:
>     if (!isset($foo['one']) {
>     trigger_error('Undefined key "one" in ...', ...);
>     }
>     return $foo['one']['two']['three'] ?? null;
>

You can have the same ability with a ? inside the brackets, and without 
the ambiguity:

// all three keys required to exist (as of PHP 9):
return $foo['one']['two']['three'];

// 'one' and 'two' required, 'three' optional:
return $foo['one']['two'][?'three'];

// both 'two' and 'three' optional:
return $foo['one'][?'two'][?'three'];

// optional all the way:
return $foo[?'one'][?'two'][?'three'];


This would maybe have similar short-cut semantics to ?->

$foo = [];
return $foo[?'one']['two'];
// OK: the ? neutralises access to the missing section of the array, 
short-cutting to NULL
// Similar to $foo?->bar->baz when $foo is NULL

$foo = ['one' => []];
return $foo[?'one']['two'];
// Error: the ? had no effect, so we're trying to access non-existent 
key 'two' in the empty array $foo['one']
// Similar to $foo?->bar->baz when $foo->bar exists


But an RFC could pin down those details.


-- 
Rowan Tommins
[IMSoP]