-- |
-- Module      : Foundation.Array.Keyed
-- License     : BSD-style
-- Maintainer  : Vincent Hanquez <vincent@snarc.org>
-- Stability   : experimental
-- Portability : portable
--
{-# LANGUAGE FlexibleInstances #-}
module Foundation.Collection.Keyed
    ( KeyedCollection(..)
    ) where

import           Basement.Compat.Base
import qualified Data.List

-- | Collection of things that can be looked up by Key
class KeyedCollection c where
    type Key c
    type Value c
    lookup :: Key c -> c -> Maybe (Value c)

instance Eq k => KeyedCollection [(k, v)] where
    type Key [(k,v)] = k
    type Value [(k,v)] = v
    lookup :: Key [(k, v)] -> [(k, v)] -> Maybe (Value [(k, v)])
lookup = k -> [(k, v)] -> Maybe v
Key [(k, v)] -> [(k, v)] -> Maybe (Value [(k, v)])
forall a b. Eq a => a -> [(a, b)] -> Maybe b
Data.List.lookup