/**
* This method iterates over the items in the either, yielding each item to the
* procedure function.
*
* @access public
* @final
* @param callable $procedure the procedure function to be used
* @return IEither\Projection the projection
*/
public final function each(callable $procedure) : IEither\Projection
{
if ($this->either->__isLeft()) {
IUnit\Type::covariant($procedure($this->either->item(), IInt32\Type::zero()));
}
return $this;
}
/**
* This method tests the "covariant" method.
*/
public function test_covariant()
{
$p0 = IUnit\Type::covariant(IUnit\Type::instance());
$this->assertInstanceOf('\\Saber\\Data\\IUnit\\Type', $p0);
$this->assertNull($p0->unbox());
$p1 = IUnit\Type::covariant(null);
$this->assertInstanceOf('\\Saber\\Data\\IUnit\\Type', $p1);
$this->assertNull($p1->unbox());
}
/**
* This method iterates over the items in the option, yielding each item to the
* procedure function.
*
* @access public
* @static
* @param IOption\Type $xs the left operand
* @param callable $procedure the procedure function to be used
* @return IOption\Type the option
*/
public static function each(IOption\Type $xs, callable $procedure) : IOption\Type
{
if ($xs->__isDefined()) {
IUnit\Type::covariant($procedure($xs->item(), IInt32\Type::zero()));
}
return $xs;
}
/**
* This method sets the procedure that will be executed should "y" equal "x".
*
* @access public
* @final
* @param Core\Equality\Type $y the object to be evaluated
* against
* @param callable $procedure the procedure to be executed
* @return Control\Choice\Type a reference to the next choice
* monad node
*/
public final function when(Core\Equality\Type $y, callable $procedure) : Control\Choice\Type
{
$this->predicate = function ($x) use($y, $procedure) {
if ($y->__eq($x)) {
IUnit\Type::covariant($procedure($x));
return true;
}
return false;
};
return Control\Choice\Type::cons($this->x, $this);
}
/**
* This method iterates over the items in the string, yielding each item to the procedure
* function.
*
* @access public
* @static
* @param IString\Type $xs the left operand
* @param callable $procedure the procedure function to be used
* @return IString\Type the string
*/
public static function each(IString\Type $xs, callable $procedure) : IString\Type
{
$xi = IString\Module::iterator($xs);
foreach ($xi as $i => $x) {
IUnit\Type::covariant($procedure($x, $i));
}
return $xs;
}
