hobbits-1.3: src/Data/Binding/Hobbits/Internal/Utilities.hs

{-# LANGUAGE Rank2Types #-}

module Data.Binding.Hobbits.Internal.Utilities where

import qualified Data.Generics as SYB



everywhereButM :: Monad m =>
  SYB.GenericQ Bool -> SYB.GenericM m -> SYB.GenericM m
everywhereButM q f x
  | q x       = return x
  | otherwise = (SYB.gmapM (everywhereButM q f) x) >>= f