pez

PEZ is a generic zipper library. It uses lenses from the fclabels package to reference a "location" to move to in the zipper. The zipper is restricted to types in the Typeable class, allowing the user to "move up" through complex data structures such as mutually-recursive types. Both the Typeable class and fclabels lenses can be derived in GHC, making it easy for the programmer to use a zipper with a minimum of boilerplate. Please send any feature requests or bug reports along. Changes 0.0.4 -> 0.1.0: