Optics.Empty.Core

This module defines the AsEmpty class, which provides a Prism for a type that may be _Empty.

Note that orphan instances for this class are defined in the Optics.Empty module from optics-extra, so if you are not simply depending on optics you may wish to import that module instead.

>>> isn't _Empty [1,2,3]True

>>> case Nothing of { Empty -> True; _ -> False }True