lib/Hcompta/Lib/Strict.hs

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