POC https://wiki.php.net/rfc/function-composition

[sgolemon]

No description provided.

[sgolemon]

Needs more testing, and as @Crell already noted on discord, there's a gap for:

class A {
    public function __invoke($x) { return $x; }
}

$cb = (new A) + (new A);

As these have no class level overloading of the add operator.

[Crell]

Interesting! That's not at all how I would have thought to do it.

If I follow, this is implemented as an operator override on closures, rather than special casing the operator itself, yes?

[Crell]

Hm, I can't even get this to compile, even with clean. Is there a file missing?

/usr/bin/ld: Zend/zend_closures.o: in function `zend_closure_do_operation':
/home/crell/Projects/Forks/php-src/Zend/zend_closures.c:714: undefined reference to `zend_composed_callable_new_from_pair'
/usr/bin/ld: Zend/zend_interfaces.o: in function `zend_register_interfaces':
/home/crell/Projects/Forks/php-src/Zend/zend_interfaces.c:681: undefined reference to `zend_register_composed_callable'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0x8): undefined reference to `zim_ComposedCallable___construct'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0x38): undefined reference to `zim_ComposedCallable___invoke'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0x68): undefined reference to `zim_ComposedCallable___debugInfo'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0x98): undefined reference to `zim_ComposedCallable_append'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0xc8): undefined reference to `zim_ComposedCallable_insert'
/usr/bin/ld: Zend/zend_interfaces.o:(.data.rel.ro+0xf8): undefined reference to `zim_ComposedCallable_prepend'