{-# LANGUAGE DeriveGeneric #-}

module Octane.Type.Primitive.List (List(..)) where

import qualified Control.DeepSeq as DeepSeq
import qualified Control.Monad as Monad
import qualified Control.Newtype as Newtype
import qualified Data.Aeson as Aeson
import qualified Data.Binary as Binary
import Data.Function ((&))
import qualified GHC.Generics as Generics
import qualified Octane.Type.Primitive.Word32LE as Word32LE

-- | A length-prefixed list.
newtype List a =
    List [a]
    deriving (Eq,Generics.Generic,Show)

instance (Binary.Binary a) => Binary.Binary (List a) where
    get = do
        (Word32LE.Word32LE size) <- Binary.get
        elements <- Monad.replicateM (fromIntegral size) Binary.get
        elements & Newtype.pack & return
    put list = do
        list & Newtype.unpack & length & fromIntegral & Word32LE.Word32LE &
            Binary.put
        list & Newtype.unpack & mapM_ Binary.put

instance Newtype.Newtype (List a)

instance (DeepSeq.NFData a) => DeepSeq.NFData (List a)

instance (Aeson.ToJSON a) => Aeson.ToJSON (List a)