lib/Hcompta/Model/Amount/Style.hs

   1 {-# LANGUAGE DeriveDataTypeable #-}
   2 module Hcompta.Model.Amount.Style where
   3
   4 import Data.Data
   5 import Data.Word (Word8)
   6 import Data.Typeable ()
   7
   8 -- * The 'Style' type
   9
  10 data Style
  11  =   Style
  12  { decimal_point :: Maybe Char
  13  , format :: Maybe Format
  14  , precision :: Word8
  15  , unit_side :: Maybe Side
  16  , unit_spaced :: Maybe Bool
  17  } deriving (Data, Eq, Ord, Read, Show, Typeable)
  18
  19 data Side
  20  =   Side_Left
  21  |   Side_Right
  22  deriving (Data, Eq, Ord, Read, Show, Typeable)
  23
  24 data Format
  25  =   Format Char [Int]
  26  deriving (Data, Eq, Ord, Read, Show, Typeable)
  27
  28 -- * Constructors
  29
  30 null :: Style
  31 null =
  32         Style
  33          { decimal_point = Nothing
  34          , format = Nothing
  35          , precision = 0
  36          , unit_side = Nothing
  37          , unit_spaced = Nothing
  38          }
  39
  40 -- * Operators
  41
  42 union :: Style -> Style -> Style
  43 union
  44  style@Style
  45  { decimal_point=decimal_point_
  46  , format=format_
  47  , precision=precision_
  48  , unit_side=side
  49  , unit_spaced=spaced
  50  }
  51  style'@Style
  52  { decimal_point=decimal_point'
  53  , format=format_'
  54  , precision=precision'
  55  , unit_side=side'
  56  , unit_spaced=spaced'
  57  } =
  58         if style == style'
  59         then style'
  60         else
  61                 Style
  62                  { decimal_point=maybe decimal_point' (const decimal_point_) decimal_point_
  63                  , format=maybe format_' (const format_) format_
  64                  , precision=max precision_ precision'
  65                  , unit_side=maybe side' (const side) side
  66                  , unit_spaced=maybe spaced' (const spaced) spaced
  67                  }