Represents a key in a scope, which is associated with a single finalizer.
A tuple that contains an open scope, together with a function that closes the scope.
The global scope, which is entirely stateless.
The global scope, which is entirely stateless. Finalizers added to the global scope will never be executed (nor kept in memory).
An effect that makes a new open scope, which provides not just the scope, but also a way to close the scope.