module Data.Tuple.HT where

-- * Pair

-- | '(Control.Arrow.***)'
{-# INLINE mapPair #-}
mapPair :: (a -> c, b -> d) -> (a,b) -> (c,d)
mapPair ~(f,g) ~(x,y) = (f x, g y)

-- | 'Control.Arrow.first'
{-# INLINE mapFst #-}
mapFst :: (a -> c) -> (a,b) -> (c,b)
mapFst f ~(a,b) = (f a, b)

-- | 'Control.Arrow.second'
{-# INLINE mapSnd #-}
mapSnd :: (b -> c) -> (a,b) -> (a,c)
mapSnd f ~(a,b) = (a, f b)


{-# INLINE swap #-}
swap :: (a,b) -> (b,a)
swap ~(x,y) = (y,x)


-- * Triple

{-# INLINE fst3 #-}
fst3 :: (a,b,c) -> a
fst3 ~(x,_,_) = x

{-# INLINE snd3 #-}
snd3 :: (a,b,c) -> b
snd3 ~(_,x,_) = x

{-# INLINE thd3 #-}
thd3 :: (a,b,c) -> c
thd3 ~(_,_,x) = x

{-# INLINE curry3 #-}
curry3 :: ((a, b, c) -> d) -> a -> b -> c -> d
curry3 f a b c = f (a,b,c)

{-# INLINE uncurry3 #-}
uncurry3 :: (a -> b -> c -> d) -> ((a, b, c) -> d)
uncurry3 f ~(a,b,c) = f a b c