Prefill the arguments of functions (Currying)

function_currying.php

<?php

function func_curry($fn)
{
	$args = array_slice(func_get_args(), 1);
	
	return function() use ($fn, $args) {
		$args = array_merge($args, func_get_args());
		return call_user_func_array($fn, $args);
	};
}

$a = function() {
	return join(func_get_args(), ", ");
};

$b = func_curry($a, "A", "B", "C");
echo $b("D", "E"); // -> A, B, C, D, E

// works on built-in functions too
$b = func_curry("strtoupper", "foo bar baz");
echo $b(); // -> FOO BAR BAZ