lib/Hcompta/Lib/Strict.hs

   1 {-# LANGUAGE DeriveDataTypeable #-}
   2 {-# LANGUAGE StandaloneDeriving #-}
   3 {-# OPTIONS_GHC -fno-warn-orphans #-}
   4 module Hcompta.Lib.Strict where
   5
   6 import Control.DeepSeq (NFData(..))
   7 import Data.Data
   8 import Data.Eq (Eq)
   9 import Data.Function ((.))
  10 import Data.Monoid (Monoid(..))
  11 import Data.NonNull (NonNull, toNullable)
  12 import Prelude (seq)
  13 import Text.Show (Show)
  14
  15 instance NFData s => NFData (NonNull s) where
  16         rnf = rnf . toNullable
  17
  18 -- * Type 'Clusive'
  19
  20 -- A data type to calculate an 'inclusive' value
  21 -- (through some propagation mecanism,
  22 -- eg. incorporating the values of the children of a tree node),
  23 -- while keeping the original 'exclusive' value
  24 -- (eg. the original value of a tree node).
  25 data Clusive a
  26  =   Clusive
  27  { exclusive :: !a
  28  , inclusive :: !a
  29  } deriving (Data, Eq, Show, Typeable)
  30 instance -- Monoid
  31  Monoid a
  32  => Monoid (Clusive a) where
  33         mempty = Clusive mempty mempty
  34         mappend (Clusive e0 i0) (Clusive e1 i1) =
  35                 Clusive (e0`mappend`e1) (i0`mappend`i1)
  36 instance -- NFData
  37  NFData a =>
  38  NFData (Clusive a) where
  39         rnf (Clusive e i)  = rnf e `seq` rnf i