9.15.1 Element

   An element is a constituent of a model. As such, it has the capability of owning other elements.

   Description

   Element has a derived composition association to itself to support the general capability for elements to own other elements.

   Generalizations

   • “Element? on page 44

   Attributes

   No additional attributes

   Associations

• / ownedElement: Element[*] The Elements owned by this element. This is a derived union.

• / owner: Element [0..1] The Element that owns this element. This is a derived union.

   Constraints

   [1] An element may not directly or indirectly own itself.

   not self.allOwnedElements()->includes(self)

   [2] Elements that must be owned must have an owner.

   self.mustBeOwned() implies owner->notEmpty()

   Additional Operations

   [1] The query allOwnedElements() gives all of the direct and indirect owned elements of an element.

   Element::allOwnedElements(): Set(Element);allOwnedElements = ownedElement->union(ownedElement->collect(e | e.allOwnedElements()))

   [2] The query mustBeOwned() indicates whether elements of this type must have an owner. Subclasses of Element that do not require an owner must override this operation.

   Element::mustBeOwned() : Boolean;mustBeOwned = true

   Semantics

   Subclasses of Element will provide semantics appropriate to the concept they represent.

   The derived ownedElement association is subsetted (directly or indirectly) by all composed association ends in the metamodel. Thus ownedElement provides a convenient way to access all the elements that are directly owned by an Element.

   Notation

   There is no general notation for an Element. The specific subclasses of Element define their own notation.