/**
* This method subscribes a listener.
*
* @access public
* @static
* @param IHashMap\Type $xs the left operand
* @param ITuple\Type $entry a tuple containing the key and listener
* @return IHashMap\Type the map
*/
public static function subscribe(IHashMap\Type $xs, ITuple\Type $entry) : IHashMap\Type
{
$k = $entry->first();
$ys = $xs->__hasKey($k) ? $xs->item($k) : ILinkedList\Type::empty_();
$ys = ILinkedList\Module::append($ys, $entry->second());
$zs = IHashMap\Module::putEntry($xs, ITuple\Type::box2($k, $ys));
return $zs;
}
/**
* This method tests the "nvl" method.
*/
public function test_nvl()
{
$x = ILinkedList\Type::make(array(1, 2, 3), '\\Saber\\Data\\IInt32\\Type');
$y = ILinkedList\Type::empty_();
$z = ILinkedList\Module::nvl($x, $y);
$this->assertInstanceOf('\\Saber\\Data\\ILinkedList\\Type', $z);
$this->assertSame(array(1, 2, 3), $z->unbox(1));
$z = ILinkedList\Module::nvl(null, $x);
$this->assertInstanceOf('\\Saber\\Data\\ILinkedList\\Type', $z);
$this->assertSame(array(1, 2, 3), $z->unbox(1));
$z = ILinkedList\Module::nvl(null, null);
$this->assertInstanceOf('\\Saber\\Data\\ILinkedList\\Type', $z);
$this->assertSame(array(), $z->unbox(1));
}
/**
* This method tests the "empty" method.
*/
public function test_empty()
{
$p0 = ILinkedList\Type::empty_();
$this->assertInstanceOf('\\Saber\\Data\\ILinkedList\\Type', $p0);
$this->assertCount(0, $p0->unbox());
}
/**
* This method returns the collection as a linked list.
*
* @access public
* @static
* @param IArrayList\Type $xs the operand
* @return ILinkedList\Type the collection as a linked list
*/
public static function toLinkedList(IArrayList\Type $xs) : ILinkedList\Type
{
return IArrayList\Module::foldLeft($xs, function (ILinkedList\Type $c, Core\Type $x) {
return ILinkedList\Module::append($c, $x);
}, ILinkedList\Type::empty_());
}
/**
* This method returns the latter value should the former value evaluates
* to null.
*
* @access public
* @static
* @param ILinkedList\Type $xs the value to be evaluated
* @param ILinkedList\Type $ys the default value
* @return ILinkedList\Type the result
*/
public static function nvl(ILinkedList\Type $xs = null, ILinkedList\Type $ys = null) : ILinkedList\Type
{
return $xs ?? $ys ?? ILinkedList\Type::empty_();
}
