是否可以从闭包创建一个命名函数？

Question

In PHP, you can have named functions like this:

function foo()
{
   return "bar";
}

And you can have Closures like this:

$foo = function() {
    return "bar";
};

Closures are awesome and easy to create, but unfortunately a library I need to use really wants a named function. Is it possible to create a named function from closures dynamically? I.e. not defining all functions in code ahead of time, but more like a register_function($name, callable $closure).

I am aware of create_function, but that one takes a PHP string as function body and just evals it, which is not what I'm looking for.

Answer 1

I don't think if it is possible to create named functions out of closures on the fly but using __call() magic method of a class, you may find this workaround helpful:

<?php

class Foo
{
    public function __call($name, $args)
    {
        if (isset($this->{$name}))
            return call_user_func_array($this->{$name}, $args);
    }
}

$foo = new Foo();
// Declaring a closure then assign it to $bar property of Foo
$foo->bar = function () { 
    echo "bar"; 
};
// Call Foo method of the same name
$foo->bar();