content: {-# OPTIONS_GHC -fno-warn-deprecations #-}
  {- |
  /DEPRECATED/: Use "Data.Generics.Uniplate.Operations" instead.
  
  This module retained Haskell 98 compatability, but users who are happy with
  multi-parameter type classes should look towards "Data.Generics.Biplate".
  
  The only function missing from "Data.Generics.Uniplate" is 'fold', as it can be
  constructed from 'children' and has little meaning in a multi-typed setting.
  
  All operations, apart from 'childrenOn' should perform identically to their non @On@
  counterparts.
  -}
  
  module Data.Generics.UniplateOn
      {- DEPRECATED "Use Data.Generics.Uniplate.Operations instead" -}
      (
      module Data.Generics.Uniplate,
      module Data.Generics.UniplateOn
      ) where
  
  import Data.Generics.Uniplate
  import Control.Monad(liftM)
  
  -- * Types
  
  -- | Return all the top most children of type @to@ within @from@.
  --
  -- If @from == to@ then this function should return the root as the single
  -- child.
  type BiplateType from to = from -> ([to], [to] -> from)
  
  
  -- * Operations
  
  -- ** Queries
  
  universeOn :: Uniplate to => BiplateType from to -> from -> [to]
  universeOn biplate x = concatMap universe $ fst $ biplate x
  
  
  -- | Return the children of a type. If @to == from@ then it returns the
  -- original element (in contrast to 'children')
  childrenOn :: Uniplate to => BiplateType from to -> from -> [to]
  childrenOn biplate x = fst $ biplate x
  
  
  -- ** Transformations
  
  transformOn :: Uniplate to => BiplateType from to -> (to -> to) -> from -> from
  transformOn biplate f x = generate $ map (transform f) current
      where (current, generate) = biplate x
  
  
  transformOnM :: (Monad m, Uniplate to) => BiplateType from to -> (to -> m to) -> from -> m from
  transformOnM biplate f x = liftM generate $ mapM (transformM f) current
      where (current, generate) = biplate x
  
  
  rewriteOn :: Uniplate to => BiplateType from to -> (to -> Maybe to) -> from -> from
  rewriteOn biplate f x = generate $ map (rewrite f) current
      where (current, generate) = biplate x
  
  
  rewriteOnM :: (Monad m, Uniplate to) => BiplateType from to -> (to -> m (Maybe to)) -> from -> m from
  rewriteOnM biplate f x = liftM generate $ mapM (rewriteM f) current
      where (current, generate) = biplate x
  
  
  descendOn :: Uniplate to => BiplateType from to -> (to -> to) -> from -> from
  descendOn biplate f x = generate $ map f current
      where (current, generate) = biplate x
  
  
  descendOnM :: (Monad m, Uniplate to) => BiplateType from to -> (to -> m to) -> from -> m from
  descendOnM biplate f x = liftM generate $ mapM f current
      where (current, generate) = biplate x
  
  
  -- ** Other
  
  
  holesOn :: Uniplate to => BiplateType from to -> from -> [(to, to -> from)]
  holesOn biplate x = uncurry f (biplate x)
    where f [] _ = []
          f (x:xs) gen = (x, gen . (:xs)) :
                         f xs (gen . (x:))
  
  
  contextsOn :: Uniplate to => BiplateType from to -> from -> [(to, to -> from)]
  contextsOn biplate x = f (holesOn biplate x)
      where
         f xs = [ (y, ctx . context)
                | (child, ctx) <- xs
                , (y, context) <- contexts child]
  
  
  -- * Helper for writing instances
  
  
  -- | Used for defining instances @UniplateFoo a => UniplateFoo [a]@
  uniplateOnList :: BiplateType a b -> BiplateType [a] b
  uniplateOnList f [] = ([], \[] -> [])
  uniplateOnList f (x:xs) =
          (a ++ as,
          \ns -> let (n1,n2) = splitAt (length a) ns in b n1 : bs n2)
      where
          (a , b ) = f x
          (as, bs) = uniplateOnList f xs
  