ledger/Hcompta/Format/Ledger/Quantity.hs

   1 {-# LANGUAGE DeriveDataTypeable #-}
   2 {-# LANGUAGE FlexibleContexts #-}
   3 {-# LANGUAGE FlexibleInstances #-}
   4 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
   5 {-# LANGUAGE OverloadedStrings #-}
   6 {-# LANGUAGE StandaloneDeriving #-}
   7 {-# LANGUAGE TypeFamilies #-}
   8 {-# OPTIONS_GHC -fno-warn-orphans #-}
   9 module Hcompta.Format.Ledger.Quantity where
  10
  11 -- import           Data.Data
  12 import           Data.Decimal
  13 -- import           Data.Eq (Eq(..))
  14 -- import           Data.Maybe (Maybe(..))
  15 -- import           Data.Ord (Ord(..))
  16 import           Data.Typeable ()
  17 import           Data.Word (Word8)
  18 -- import           Prelude (Num(..))
  19
  20 -- import qualified Hcompta.Polarize as Polarize
  21 -- import qualified Hcompta.Quantity as Quantity
  22 import qualified Hcompta.Filter.Amount as Filter.Amount
  23
  24 -- * Type 'Quantity'
  25 type Quantity = Filter.Amount.Quantity
  26 {-
  27 deriving instance Data Quantity
  28
  29 instance Quantity.Zero Quantity where
  30         quantity_zero = 0
  31         quantity_null = (==) 0 -- . decimalMantissa
  32 instance Quantity.Addable Quantity where
  33         quantity_add = (+)
  34 instance Quantity.Negable Quantity where
  35         quantity_neg = negate
  36 instance Polarize.Polarizable Quantity where
  37         polarizable_negative q =
  38                 case q of
  39                  _ | q < 0 -> Just q
  40                  _         -> Nothing
  41         polarizable_positive q =
  42                 case q of
  43                  _ | q <= 0 -> Nothing
  44                  _          -> Just q
  45 -}
  46
  47 quantity_round :: Word8 -> Quantity -> Quantity
  48 quantity_round = Data.Decimal.roundTo