Support for nullsafe function call syntax

[heiglandreas]

Support for nullsafe function call syntax

[iluuu1994]

This is mentioned in the RFC too:

A nullsafe function call syntax ($callableOrNull?()) is also outside of scope for this RFC.

[iluuu1994]

@heiglandreas I wouldn't mind keeping this around as a feature request. But do note that I'm not sure this syntax is feasible due to the aforementioned lookahead problem.

[iluuu1994]

$foo?() is not supported syntax. It's also ambiguous (without lookahead) because of $foo?(expr):(other_expr).

[bwoebi]

switch ($expr) { case $var?(2):foo: do_things(); } is fundamentally ambiguous here anyway, independently of lookahead. Is $var?(2) (the nullsafe fcall) the case expression and foo:do_things() the body (a goto label and a function call), or $var?(2):foo (a ternary with foo constant in else part) and do_things() the body?

[iluuu1994]

Right. Some other languages do $foo?.() for syntax to avoid the ambiguity.

[marc-mabe]

Right. Some other languages do $foo?.() for syntax to avoid the ambiguity.

Or $foo?->() to be more PHP like (this should allow $foo->() as well for consistency), which makes it end up in two different short style variants doing the same thing :/

Another option would be to make the callback argument of call_user_func[_array] nullable. Not as nice/readable as native syntax but an option.