OneToTwo.hs

module Data.Loc.List.OneToTwo
  ( -- * Imports
    -- $imports

    -- * Type
    OneToTwo (..),

    -- * Tuple conversion
    toTuple,
    toTuple',
  )
where

import Data.Loc.Internal.Prelude

-- | List of length 1 or 2
data OneToTwo a
  = -- | List of length 1
    One a
  | -- | List of length 2
    Two a a
  deriving (Eq, Ord, Show, Read, Foldable, Functor)

-- |
--
-- >>> toTuple (One 1)
-- (1,Nothing)
--
-- >>> toTuple (Two 1 2)
-- (1,Just 2)
toTuple :: OneToTwo a -> (a, Maybe a)
toTuple =
  \case
    One a -> (a, Nothing)
    Two a b -> (a, Just b)

-- |
--
-- >>> toTuple' (One 1)
-- (Nothing,1)
--
-- >>> toTuple' (Two 1 2)
-- (Just 1,2)
toTuple' :: OneToTwo a -> (Maybe a, a)
toTuple' =
  \case
    One a -> (Nothing, a)
    Two a b -> (Just a, b)

-- $imports
--
-- Recommended import:
--
-- > import Data.Loc.List.OneToTwo (OneToTwo)
-- > import qualified Data.Loc.List.OneToTwo as OneToTwo