{-# LANGUAGE UndecidableInstances #-}
module Prologue
  ( module X
  , foldMapA
  , maybeM
  , maybeLast
  , fromMaybeLast
  ) where


import Data.Bifunctor.Join as X
import Data.Bits as X
import Data.ByteString as X (ByteString)
import Data.Functor.Both as X (Both, both, runBothWith)
import Data.IntMap as X (IntMap)
import Data.IntSet as X (IntSet)
import Data.Ix as X (Ix (..))
import Data.List.NonEmpty as X (NonEmpty (..), nonEmpty, some1)
import Data.Map as X (Map)
import Data.Maybe as X
import Data.Monoid (Alt (..))
import Data.Sequence as X (Seq)
import Data.Semilattice.Lower as X (Lower(..))
import Data.Set as X (Set)
import Data.Sum as X (Sum, Element, Elements, (:<), (:<:), Apply (..), inject)
import Data.Text as X (Text)
import Data.These as X
import Data.Union as X

import Control.Exception as X hiding (Handler (..), assert, evaluate, throw, throwIO, throwTo)

-- Typeclasses
import Control.Applicative as X
import Control.Arrow as X ((&&&), (***))
import Control.Monad as X hiding (fail, return, unless, when)
import Control.Monad.Except as X (MonadError (..))
import Control.Monad.Fail as X (MonadFail (..))
import Data.Algebra as X
import Data.Bifoldable as X
import Data.Bifunctor as X (Bifunctor (..))
import Data.Bitraversable as X
import Data.Foldable as X hiding (product, sum)
import Data.Function as X (fix, on, (&))
import Data.Functor as X (void, ($>))
import Data.Functor.Classes as X
import Data.Functor.Classes.Generic as X
import Data.Functor.Foldable as X (Base, Corecursive (..), Recursive (..))
import Data.Hashable as X (Hashable, hash, hashUsing, hashWithSalt)
import Data.Hashable.Lifted as X (Hashable1(..), hashWithSalt1)
import Data.Monoid as X (First (..), Last (..), Monoid (..))
import Data.Proxy as X (Proxy (..))
import Data.Semigroup as X (Semigroup (..))
import Data.Traversable as X
import Data.Typeable as X (Typeable)

-- Generics
import GHC.Generics as X hiding (moduleName)
import GHC.Stack as X

-- | Fold a collection by mapping each element onto an 'Alternative' action.
foldMapA :: (Alternative m, Foldable t) => (b -> m a) -> t b -> m a
foldMapA f = getAlt . foldMap (Alt . f)


maybeLast :: Foldable t => b -> (a -> b) -> t a -> b
maybeLast b f = maybe b f . getLast . foldMap (Last . Just)

fromMaybeLast :: Foldable t => a -> t a -> a
fromMaybeLast b = fromMaybe b . getLast . foldMap (Last . Just)

-- | Extract the 'Just' of a 'Maybe' in an 'Applicative' context or, given 'Nothing', run the provided action.
maybeM :: Applicative f => f a -> Maybe a -> f a
maybeM f = maybe f pure