[PHP FUNCTIONAL PROGRAMMING PATTERNS] Function builder

function_builder.php

<?php

$discount = function($percent){
	return function($price) use ($percent){
		return ($price - ($price * $percent * 0.01));
	};
};

$half_off = $discount(50);
echo $half_off(500);

$quarter_off = $discount(25);
echo $quarter_off(500);