/**
* This method returns a "cons" object for a choice.
*
* @access public
* @static
* @param Core\Equality\Type $x the object to be evaluated
* @param Control\Choice\Type $xs the tail
* @return Control\Choice\Type the "cons" object
*/
public static function cons(Core\Equality\Type $x, Control\Choice\Type $xs) : Control\Choice\Type
{
if ($xs !== null) {
return new Control\Choice\Cons\Type($x, $xs);
}
return new Control\Choice\Cons\Type($x, Control\Choice\Type::nil());
}
/**
* This method returns a choice monad for evaluating an object.
*
* @access public
* @static
* @param Core\Equality\Type $x the object to be evaluated
* @return Control\Choice\Type the choice monad
*/
public static function choice(Core\Equality\Type $x) : Control\Choice\Type
{
return Control\Choice\Type::cons($x, Control\Choice\Type::nil());
}
