module Protocol.Utils where
import Control.Applicative (Applicative(..), Alternative(..))
import Control.Monad (Monad(..), join, mapM, unless, zipWithM)
import Control.Monad.Trans.Class (MonadTrans(..))
import Data.Bool
import Data.Either (either)
import Data.Eq (Eq(..))
import Data.Foldable (Foldable, foldMap, and, sequenceA_)
import Data.Function (($), id, const)
import Data.Functor (Functor, (<$>), (<$))
import Data.Functor.Identity (Identity(..))
import Data.Functor.Compose (Compose(..))
import Data.Maybe (Maybe(..), maybe, fromMaybe)
import Data.Ord (Ord(..))
import Data.Semigroup (Semigroup(..))
import Data.Text (Text)
import Data.Traversable (Traversable(..))
import Data.Tuple (fst, snd, uncurry)
import GHC.Natural (minusNaturalMaybe)
import Numeric.Natural (Natural)
import Prelude (fromIntegral)
import Text.Show (Show(..))
import Control.Monad.Trans.Maybe (MaybeT(..))
import qualified Control.Monad.Trans.Except as Exn
import qualified Control.Monad.Trans.State.Strict as S
import qualified Data.ByteString as BS
import qualified Data.List as List

-- | NOTE: check the lengths before applying @f@.
isoZipWith :: (a->b->c) -> [a]->[b]->Maybe [c]
isoZipWith f as bs
 | List.length as /= List.length bs = Nothing
 | otherwise = Just (List.zipWith f as bs)

-- | NOTE: check the lengths before applying @f@.
isoZipWith3 :: (a->b->c->d) -> [a]->[b]->[c]->Maybe [d]
isoZipWith3 f as bs cs
 | al /= List.length bs = Nothing
 | al /= List.length cs = Nothing
 | otherwise = Just (List.zipWith3 f as bs cs)
 where al = List.length as

isoZipWithM ::
 Applicative m =>
 m () ->
 (a -> b -> m c) ->
 [a] -> [b] -> m [c]
isoZipWithM err f as bs =
	maybe ([] <$ err) sequenceA $
		isoZipWith f as bs

isoZipWith3M ::
 Applicative m =>
 m () ->
 (a -> b -> c -> m d) ->
 [a] -> [b] -> [c] -> m [d]
isoZipWith3M err f as bs cs =
	maybe ([] <$ err) sequenceA $
		isoZipWith3 f as bs cs

isoZipWith3M_ ::
 Applicative m =>
 m () ->
 (a -> b -> c -> m d) ->
 [a] -> [b] -> [c] ->
 m ()
isoZipWith3M_ err f as bs cs =
	maybe err sequenceA_ $
		isoZipWith3 f as bs cs