An existence condition, that is, the keyword ‘exists’, followed by either an (optionally typed) specified variable or an (untyped) member name.

Examples:

exists name
exists firstItem = first?.item

no subtypes hierarchy

Initializer
ExistsCondition(SpecifiedVariable|MemberName variable)
Parameters:
  • variable

    The variable being tested.

Attributes
childrenSource Codeshared actual [SpecifiedVariable|LIdentifier] children

The child nodes of this node.

hashSource Codeshared actual Integer hash

The hash value of the value, which allows the value to be an element of a hash-based set or key of a hash-based map. Implementations must respect the constraint that:

  • if x==y then x.hash==y.hash.

Therefore, a class which refines equals must also refine hash.

Refines Object.hash
variableSource Codeshared actual SpecifiedVariable|MemberName variable

The variable being tested.

Inherited Attributes
Attributes inherited from: Node
Attributes inherited from: Object
Methods
copySource Codeshared ExistsCondition copy(SpecifiedVariable|MemberName variable = ...)
Parameters:
  • variable = this.variable
equalsSource Codeshared actual Boolean equals(Object that)

Determine if two values are equal. Implementations should respect the constraints that:

  • if x===y then x==y (reflexivity),
  • if x==y then y==x (symmetry),
  • if x==y and y==z then x==z (transitivity).

Furthermore it is recommended that implementations ensure that if x==y then x and y have the same concrete class.

A class which explicitly refines equals() is said to support value equality, and the equality operator == is considered much more meaningful for such classes than for a class which simply inherits the default implementation of identity equality from Identifiable.

transformSource Codeshared actual Result transform<out Result>(Transformer<Result> transformer)

Transform this node with the given transformer by calling the appropriate transformX method on the transformer.

If you have a Node node that’s actually an LIdentifier instance, then the runtime will call LIdentifier.transform; therefore, this method is by nature narrowing. This means that if transformer is a NarrowingTransformer, calling node.transform(transformer) is equivalent to calling transformer.transformNode(node). On the other hand, if transformer is a WideningTransformer, then the two operations are very different.

Inherited Methods
Methods inherited from: Node