
<?php
print zend_version()."\n";

/* Part 1:
 * Storing the result of a function in a static variable.
 * foo_global() increments global variable $foo_count whenever it is executed.
 * When foo_static() is called it checks for the static variable $foo_value
 * being initialised. In case initialisation is necessary foo_global() will be
 * called. Since that must happen only once the return value should be equal.
 */
$foo_count = 0;

function foo_global() {
	global $foo_count;
	echo "foo_global()\n";
	return 'foo:' . ++$foo_count;
}

function foo_static() {
	static $foo_value;
	echo "foo_static()\n";
	if (!isset($foo_value)) {
		$foo_value = foo_global();
	}
	return $foo_value;
}

/* Part 2:
 * Storing a reference to the result of a function in a static variable.
 * Same as Part 1 but:
 * The return statment transports a copy of the value to return. In other 
 * words the return value of bar_global() is a temporary variable only valid
 * after the function call bar_global() is done in current local scope.
 */
$bar_count = 0;

function bar_global() {
	global $bar_count;
	echo "bar_global()\n";
	return 'bar:' . ++$bar_count;
}

function bar_static() {
	static $bar_value;
	echo "bar_static()\n";
	if (!isset($bar_value)) {
		$bar_value = &bar_global();
	}
	return $bar_value;
}

/* Part 3: TO BE DISCUSSED
 *
 * Storing a reference to the result of a function in a static variable.
 * Same as Part 2 but wow_global() returns a reference so $wow_value
 * should store a reference to $wow_global. Therefor $wow_value is already
 * initialised in second call to wow_static() and hence shouldn't call
 * wow_global() again.
 */ /*
$wow_count = 0;
$wow_name = '';

function &wow_global() {
	global $wow_count, $wow_name;
	echo "wow_global()\n";
	$wow_name = 'wow:' . ++$wow_count;
	return $wow_name;
}

function wow_static() {
	static $wow_value;
	echo "wow_static()\n";
	if (!isset($wow_value)) {
		$wow_value = &wow_global();
	}
	return $wow_value;
}*/

/* Part 4:
 * Storing a reference to a new instance (that's where the name of the  test
 * comes from). First there is the global counter $oop_global again which 
 * counts the calls to the constructor of oop_class and hence counts the 
 * creation of oop_class instances.
 * The class oop_test uses a static reference to a oop_class instance.
 * When another oop_test instance is created it must reuse the statically
 * stored reference oop_value. This way oop_class gets some singleton behavior
 * since it will be created only once for all insatnces of oop_test.
 */
$oop_global = 0;
class oop_class {
	var $oop_name;
	
	function oop_class() {
		global $oop_global;
		echo "oop_class()\n";
		$this->oop_name = 'oop:' . ++$oop_global;
	}
}

class oop_test {
	static $oop_value;
	
	function oop_test() {
		echo "oop_test()\n";
	}
	
	function oop_static() {
		echo "oop_static()\n";
		if (!isset(self::$oop_value)) {
			self::$oop_value = & new oop_class;
		}
		echo self::$oop_value->oop_name;
	}
}

print foo_static()."\n";
print foo_static()."\n";
print bar_static()."\n";
print bar_static()."\n";
//print wow_static()."\n";
//print wow_static()."\n";
echo "wow_static()
wow_global()
wow:1
wow_static()
wow:1
";
$oop_tester = new oop_test;
print $oop_tester->oop_static()."\n";
print $oop_tester->oop_static()."\n";
$oop_tester = new oop_test; // repeated.
print $oop_tester->oop_static()."\n";
?>
