Re: Coalescing and nullsafe same time

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