Class UML 2.5::LiteralNull

Description:

A LiteralNull specifies the lack of a value.

Direct Superclasses: LiteralSpecification

Direct Subclasses:

Class Precedence List: LiteralNull, LiteralSpecification, ValueSpecification, TypedElement, PackageableElement, ParameterableElement, NamedElement, Element

Properties:

type : Type (0 1); -- source TypedElement
visibility : VisibilityKind (0 1); -- source PackageableElement

A PackageableElement must have a visibility specified if it is owned by a Namespace. The default visibility is public.
Redefines: NamedElement.visibility
Default value: PUBLIC

owningTemplateParameter : TemplateParameter (0 1); -- source ParameterableElement
templateParameter : TemplateParameter (0 1); -- source ParameterableElement

The TemplateParameter that exposes this ParameterableElement as a formal parameter.
Opposite: TemplateParameter.parameteredElement

clientDependency : Dependency (0 *); -- source NamedElement
name : String (0 1); -- source NamedElement
nameExpression : StringExpression (0 1); -- source NamedElement
namespace : Namespace (0 1); -- source NamedElement
qualifiedName : String (0 1); -- source NamedElement
ownedComment : Comment (0 *); -- source Element

The Comments owned by this Element.
{composite}
Subsets: Element.ownedElement

ownedElement : Element (0 *); -- source Element

The Elements owned by this Element.
{composite, readonly}
Derived union with sources: (ownedComment, nameExpression)
Opposite: Element.owner

owner : Element (0 1); -- source Element

The Element that owns this Element.
{readonly}
Derived union with sources: (namespace, owningTemplateParameter)
Opposite: Element.ownedElement

Constraints:

No additional constraints.

Operations:

Signature: isNull() : Boolean;
Description: The query isNull() returns true.
Expression: result = (true)

Signature: isComputable() : Boolean;
Description: The query isComputable() is redefined to be true.
Expression: result = (true)

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