zipWithFM :: Ord k => (u -> v -> w) -> v -> Map k u -> Map k v -> [(k,w)]
zipWithFM f v0 mu mv = [ (k,f u (M.findWithDefault v0 k mv) ) | (k,u) <- M.assocs mu]
zipWithFM :: Ord k => (u -> v -> w) -> v -> Map k u -> Map k v -> [(k,w)]
zipWithFM f v0 mu mv = [ (k,f u (M.findWithDefault v0 k mv) ) | (k,u) <- M.assocs mu]
zipWithFM f v0 mu mv = [ (k,f u (M.findWithDefault v0 k mv) ) | (k,u) <- M.assocs mu]