[Haskell-cafe] searching via zipper over a tree

Hi folks, I'm studying zippers (and by extension, the State monad), and have written a function for finding the first node-location in a 'zippered' tree that satisfies a predicate: http://paste.lisp.org/display/59636 (The code uses Krasimir Angelov's Data.Tree.Zipper.) My code works, but I suspect that I'm working too hard. I would appreciate any comments! Regards, Graham