{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE StandaloneDeriving #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hcompta.Lib.Strict where

import Control.DeepSeq (NFData(..))
import Data.Data
import Data.Eq (Eq)
import Data.Function ((.))
import Data.Monoid (Monoid(..))
import Data.NonNull (NonNull, toNullable)
import Prelude (seq)
import Text.Show (Show)

instance NFData s => NFData (NonNull s) where
	rnf = rnf . toNullable

-- * Type 'Clusive'

-- A data type to calculate an 'inclusive' value
-- (through some propagation mecanism,
-- eg. incorporating the values of the children of a tree node),
-- while keeping the original 'exclusive' value
-- (eg. the original value of a tree node).
data Clusive a
 =   Clusive
 { exclusive :: !a
 , inclusive :: !a
 } deriving (Data, Eq, Show, Typeable)
instance -- Monoid
 Monoid a
 => Monoid (Clusive a) where
	mempty = Clusive mempty mempty
	mappend (Clusive e0 i0) (Clusive e1 i1) =
		Clusive (e0`mappend`e1) (i0`mappend`i1)
instance -- NFData
 NFData a =>
 NFData (Clusive a) where
	rnf (Clusive e i)  = rnf e `seq` rnf i