chain_hyper.md
In rswipl: Embed 'SWI'-'Prolog'

class chain_hyper {#class-chain_hyper}

Class chain_hyper is a subclass of the general binary relation class hyper. It redefines the ->unlink_from and ->unlink_to methods, making both objects dependent. I.e. if the <-from object is deleted, the ->to will be sent a ->destroy or ->free and visa-versa.

If dependent destruction is not desired after all, the user should first ->free the hyper-relation.

chain_hyper->unlink_to ->free <-from.
chain_hyper->unlink_from If the <-to objects is alreeady being destroyed (see ->unlinking), do nothing. Else, if the <-to object understands ->destroy, invoke this method, else invoke ->free