mirror of
https://github.com/simonmichael/hledger.git
synced 2024-09-20 02:37:12 +03:00
110 lines
3.3 KiB
Haskell
110 lines
3.3 KiB
Haskell
{-|
|
|
An 'Amount' is some quantity of money, shares, or anything else.
|
|
|
|
A simple amount is a commodity, quantity pair (where commodity can be anything):
|
|
|
|
@
|
|
$1
|
|
£-50
|
|
EUR 3.44
|
|
GOOG 500
|
|
1.5h
|
|
90apples
|
|
0
|
|
@
|
|
|
|
A mixed amount (not yet implemented) is one or more simple amounts:
|
|
|
|
@
|
|
$50, EUR 3, AAPL 500
|
|
16h, $13.55, oranges 6
|
|
@
|
|
|
|
Commodities may be convertible or not. A mixed amount containing only
|
|
convertible commodities can be converted to a simple amount. Arithmetic
|
|
examples:
|
|
|
|
@
|
|
$1 - $5 = $-4
|
|
$1 + EUR 0.76 = $2
|
|
EUR0.76 + $1 = EUR 1.52
|
|
EUR0.76 - $1 = 0
|
|
($5, 2h) + $1 = ($6, 2h)
|
|
($50, EUR 3, AAPL 500) + ($13.55, oranges 6) = $67.51, AAPL 500, oranges 6
|
|
($50, EUR 3) * $-1 = $-53.96
|
|
($50, AAPL 500) * $-1 = error
|
|
@
|
|
-}
|
|
|
|
module Ledger.Amount
|
|
where
|
|
import Ledger.Utils
|
|
import Ledger.Types
|
|
import Ledger.Commodity
|
|
|
|
|
|
instance Show Amount where show = showAmount
|
|
|
|
-- | Get the string representation of an amount, based on its commodity's
|
|
-- display settings.
|
|
showAmount :: Amount -> String
|
|
showAmount (Amount (Commodity {symbol=sym,side=side,spaced=spaced,precision=p}) q)
|
|
| side==L = printf "%s%s%s" sym space quantity
|
|
| side==R = printf "%s%s%s" quantity space sym
|
|
where
|
|
space = if spaced then " " else ""
|
|
quantity = punctuatethousands $ printf ("%."++show p++"f") q
|
|
|
|
-- | Add thousands-separating commas to a decimal number string
|
|
punctuatethousands :: String -> String
|
|
punctuatethousands s =
|
|
sign ++ (addcommas int) ++ frac
|
|
where
|
|
(sign,num) = break isDigit s
|
|
(int,frac) = break (=='.') num
|
|
addcommas = reverse . concat . intersperse "," . triples . reverse
|
|
triples [] = []
|
|
triples l = [take 3 l] ++ (triples $ drop 3 l)
|
|
|
|
-- | Get the string representation of an amount, rounded, or showing just "0" if it's zero.
|
|
showAmountOrZero :: Amount -> String
|
|
showAmountOrZero a
|
|
| isZeroAmount a = "0"
|
|
| otherwise = showAmount a
|
|
|
|
-- | is this amount zero, when displayed with its given precision ?
|
|
isZeroAmount :: Amount -> Bool
|
|
isZeroAmount a@(Amount c _ ) = nonzerodigits == ""
|
|
where nonzerodigits = filter (`elem` "123456789") $ showAmount a
|
|
|
|
instance Num Amount where
|
|
abs (Amount c q) = Amount c (abs q)
|
|
signum (Amount c q) = Amount c (signum q)
|
|
fromInteger i = Amount (comm "") (fromInteger i)
|
|
(+) = amountop (+)
|
|
(-) = amountop (-)
|
|
(*) = amountop (*)
|
|
|
|
-- | Apply a binary arithmetic operator to two amounts, converting to the
|
|
-- second one's commodity and adopting the lowest precision. (Using the
|
|
-- second commodity means that folds (like sum [Amount]) will preserve the
|
|
-- commodity.)
|
|
amountop :: (Double -> Double -> Double) -> Amount -> Amount -> Amount
|
|
amountop op a@(Amount ac aq) b@(Amount bc bq) =
|
|
Amount bc ((quantity $ convertAmountTo bc a) `op` bq)
|
|
|
|
-- | Convert an amount to the specified commodity using the appropriate
|
|
-- exchange rate.
|
|
convertAmountTo :: Commodity -> Amount -> Amount
|
|
convertAmountTo c2 (Amount c1 q) = Amount c2 (q * conversionRate c1 c2)
|
|
|
|
-- | Sum a list of amounts. This is still needed because a final zero
|
|
-- amount will discard the sum's commodity.
|
|
sumAmounts :: [Amount] -> Amount
|
|
sumAmounts = sum . filter (not . isZeroAmount)
|
|
|
|
nullamt = Amount (comm "") 0
|
|
|
|
-- temporary value for partial entries
|
|
autoamt = Amount (Commodity {symbol="AUTO",side=L,spaced=False,comma=False,precision=0,rate=1}) 0
|