Vadim Dvorovenko <vadim.dvorovenko@gmail.com>:
> Sorry for raising such an ancient topic.
>
> Аccidentally noticed, that construction like
> `$arr['undefined']?->foo()->bar` causes error, and not behaves the same,
> as `($arr['undefined'] ?? null)?->foo()->bar`.
>
> Readed docs, https://wiki.php.net/rfc/nullsafe_operator, asked google
> and learned, that there were much discussions about such behavior, and
> it was chosen deliberately. Nevertheless, structures like
> `(($arr['undefined'] ?? null)?->foo()->bar)` does not looks pretty for
> me. `$arr['undefined']->foo->bar ?? null` works great, until function
> calls appears in chain, and `$arr['undefined']->foo()->bar ?? null`
> breaks. It looks like objects are our favorites for short and safe
> operations, but arrays are not.
>
> But during development, you can equally easily encounter typed arrays
> (for example, with a structure described through phpdocs), and working
> directly with properties, and traditional getters. An structured
> associative array that has optional fields is also a common pattern. And
> in large projects these patterns they can be found in almost any
> combination.
>
> So it looks like the language needs a construct for pretty code in such
> cases. What do you think it should look like?
>
> * Make nullsafe operator to be coalescing too. Making
> `$arr['undefined']?->foo()->bar` no to cause error, but return null
>
> * Some new coalescing-nullsafe-operator, `??->`.
> `$arr['undefined']??->foo()->bar` suppressing all errors to the left
> same way `??` does.
>
> * Some new nullsafe-array-access operator `$arr?-['key']`. This leads to
> `$arr?-['key']->foo()->bar` for cases where we are sure that array has
> key. Supposed short-circuiting working here too.
>
> * Some new coalesce-array-access operators `$arr??-['key']`. Making
> `$arr??-['key']->foo()->bar` for cases, there we are not sure, that
> array has key.
>
> * Suppress function call on nulls and undefined errors in
> `$var->foo()->bar() ?? null`.
>
Hi, Vadim!
I've seen discussions about that and also considered proposing something
similar, so thank you for bringing that up!
I see two questions here:
1. Accessing an array offset on a nullable value ($arrayOrNull['offset'])
2. Treating a non-existent array offset as null ($objects[0]?->prop)
For the first case, the syntax could be symmetric to ?->:
? + -> = ?->
? + [$offset] = ?[$offset]
$arrayOrNull?['offset'] , equivalent to $arrayOrNull === null ? null :
$arrayOrNull['offset']
For the second case:
$objects[?0]?->prop , equivalent to ($objects[0] ?? null)?->prop
--
Valentin
