Edsko de Vries wrote: > Hey, > > I have a structure containing Xs in various places, like so > > data X > data Structure = Structure .. [X] .. [X] .. > > And I defined mapStructure > > mapStructure :: (X -> X) -> (Structure -> Structure) > > I then wanted to use mapStructure to define queries as well as > transformations on structures. I generalized mapStructure to > mapStructureM: > > mapStructure :: Monad m => (X -> m X) -> (Structure -> m Structure)
I guess you want an applicative functor. See also http://haskell.org/ghc/docs/latest/html/libraries/base/Data-Traversable.html and the accompanying papers. Regards, apfelmus _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
