Language: Closure::fromCallable() and Closure::bindTo() (Zend zend_closures.c parity) #3266

Category

language

Problem

Closure::fromCallable() and Closure::bindTo() are not available on the VM builtin Closure class. PHP 7.1+ code uses fromCallable for first-class callables; bindTo rebinding is distinct from Closure::bind() tracked in #3097.

php-src reference

• Zend/zend_closures.c — zend_closure_from_callable, zend_closure_bind_to
• ext/standard/basic_functions.c — userland exposure

Repro (today)

<?php
class C {
    private function secret(): string { return 'ok'; }
    public function get(): Closure {
        return Closure::fromCallable([$this, 'secret']);
    }
}
$c = new C();
echo ($c->get())();

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh && php bin/vm.php repro-from-callable.php'
# LogicException / undefined method fromCallable

php repro-from-callable.php
# Zend: ok

bindTo repro

<?php
$fn = function () { return $this->x; };
class D { public int $x = 42; }
$bound = $fn->bindTo(new D(), D::class);
echo $bound();

Scope (this repo)

Done when

• Closure::fromCallable('strlen') returns invokable equivalent to strlen under VM
• Closure::fromCallable([$obj, 'method']) respects visibility like Zend
• bindTo($newThis, $newScope) matches Zend scope semantics for private/protected access
• Document interaction with Stdlib: is_callable / call_user_func / call_user_func_array (ext/standard parity) #3132 call_user_func* if callable is not yet implemented

Labels

language, implementation-ready