gistfile1.aw

<?php
ini_set('display_errors', 'On');
error_reporting(E_ALL);


define('TYPEHINT_PCRE', '/^Argument (\d)+ passed to (?:(\w+)::)?(\w+)\(\) must be an instance of (\w+), (\w+) given/i');

class TypeHint {
	
	private static $error_handler;
	
	private static $type_callbacks = array(
		'boolean' => 'is_bool',
		'integer' => 'is_int',
		'double' => 'is_float',
		'numeric' => 'is_numeric',
		'string' => 'is_string',
		'object' => 'is_object'
	);

	private function __construct() {}
	
	public static function activate() {
		self::$error_handler = set_error_handler('TypeHint::handleTypehinting');
	}
	
	public static function deactivate() {
		set_error_handler(self::$error_handler);
	}

	private static function getArgument($contexts, $fn, $index, &$argument) {
		foreach($contexts as $context) {
			if(isset($context['function']) && $context['function'] == $fn) {
				$argument = $context['args'][$index - 1];
				return true;
			}
		}
	return false;
	}
	
	public static function handleTypehinting($error_code, $error_message, $file, $line) {
		if($error_code == E_RECOVERABLE_ERROR) {
			if(preg_match(TYPEHINT_PCRE, $error_message, $matches)) {
				list($match, $index, $class, $fn, $hint, $type) = $matches;

				if(isset(self::$type_callbacks[strtolower($hint)])) {
					$argument = null;
					$contexts = debug_backtrace();

					if(self::getArgument($contexts, $fn, $index, $argument)) {
						if(call_user_func(self::$type_callbacks[strtolower($hint)], $argument))
							return true;
					}
				}
			}
		}
	return false;
	}

}

TypeHint::activate();



function testInteger(Integer $obj) {
	var_dump($obj);
}

testInteger(15);
testInteger(1.5); // Throws catchable fatal error
?>