first attempt at storing per-amount price

Ledger/Amount.hs

@@ -48,45 +48,47 @@ instance Show Amount where show = showAmount
 instance Show MixedAmount where show = showMixedAmount
 
 instance Num Amount where
-    abs (Amount c q) = Amount c (abs q)
+    abs (Amount c q p) = Amount c (abs q) p
-    signum (Amount c q) = Amount c (signum q)
+    signum (Amount c q p) = Amount c (signum q) p
-    fromInteger i = Amount (comm "") (fromInteger i)
+    fromInteger i = Amount (comm "") (fromInteger i) Nothing
     (+) = amountop (+)
     (-) = amountop (-)
     (*) = amountop (*)
 
 instance Num MixedAmount where
-    fromInteger i = Mixed [Amount (comm "") (fromInteger i)]
+    fromInteger i = Mixed [Amount (comm "") (fromInteger i) Nothing]
     negate (Mixed as) = Mixed $ map negate as
     (+) (Mixed as) (Mixed bs) = normaliseMixedAmount $ Mixed $ filter (not . isZeroAmount) $ as ++ bs
     (*)    = error "programming error, mixed amounts do not support multiplication"
     abs    = error "programming error, mixed amounts do not support abs"
     signum = error "programming error, mixed amounts do not support signum"
 
--- | Apply a binary arithmetic operator to two amounts, converting
+-- | Apply a binary arithmetic operator to two amounts - converting to the
--- to the second one's commodity and adopting the lowest
+-- second one's commodity, adopting the lowest precision, and discarding
--- precision. (Using the second commodity is best since sum and
+-- any price information. (Using the second commodity is best since sum
--- other folds start with a no-commodity amount.)
+-- and other folds start with a no-commodity amount.)
 amountop :: (Double -> Double -> Double) -> Amount -> Amount -> Amount
-amountop op a@(Amount ac aq) b@(Amount bc bq) = 
+amountop op a@(Amount ac aq ap) b@(Amount bc bq bp) = 
-    Amount bc ((quantity $ convertAmountTo bc a) `op` bq)
+    Amount bc ((quantity $ convertAmountTo bc a) `op` bq) Nothing
 
 -- | Convert an amount to the specified commodity using the appropriate
 -- exchange rate (which is currently always 1).
 convertAmountTo :: Commodity -> Amount -> Amount
-convertAmountTo c2 (Amount c1 q) = Amount c2 (q * conversionRate c1 c2)
+convertAmountTo c2 (Amount c1 q p) = Amount c2 (q * conversionRate c1 c2) Nothing
 
 -- | 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,comma=comma,precision=p}) q)
+showAmount (Amount (Commodity {symbol=sym,side=side,spaced=spaced,comma=comma,precision=p}) q pri)
     | sym=="AUTO" = "" -- can display one of these in an error message
-    | side==L = printf "%s%s%s" sym space quantity
+    | side==L = printf "%s%s%s%s" sym space quantity price
-    | side==R = printf "%s%s%s" quantity space sym
+    | side==R = printf "%s%s%s%s" quantity space sym price
     where 
       space = if spaced then " " else ""
       quantity = commad $ printf ("%."++show p++"f") q
       commad = if comma then punctuatethousands else id
+      price = case pri of (Just pamt) -> " @ " ++ showMixedAmount pamt
+                          Nothing -> ""
 
 -- | Add thousands-separating commas to a decimal number string
 punctuatethousands :: String -> String
@@ -101,7 +103,7 @@ punctuatethousands s =
 
 -- | Does this amount appear to be zero when displayed with its given precision ?
 isZeroAmount :: Amount -> Bool
-isZeroAmount a@(Amount c _ ) = nonzerodigits == ""
+isZeroAmount a = nonzerodigits == ""
     where nonzerodigits = filter (`elem` "123456789") $ showAmount a
 
 -- | Access a mixed amount's components.
@@ -114,8 +116,7 @@ isZeroMixedAmount :: MixedAmount -> Bool
 isZeroMixedAmount = all isZeroAmount . amounts . normaliseMixedAmount
 
 -- | Get the string representation of a mixed amount, showing each of
--- its component amounts. We currently display them on one line but
+-- its component amounts.
--- will need to change to ledger's vertical layout.
 showMixedAmount :: MixedAmount -> String
 showMixedAmount m = concat $ intersperse ", " $ map show as
     where (Mixed as) = normaliseMixedAmount m
@@ -142,5 +143,5 @@ nullamt = Mixed []
 
 -- | A temporary value for parsed transactions which had no amount specified.
 missingamt :: MixedAmount
-missingamt = Mixed [Amount (Commodity {symbol="AUTO",side=L,spaced=False,comma=False,precision=0}) 0]
+missingamt = Mixed [Amount (Commodity {symbol="AUTO",side=L,spaced=False,comma=False,precision=0}) 0 Nothing]
 

Ledger/Commodity.hs

@@ -23,10 +23,10 @@ euro    = Commodity {symbol="EUR",side=L,spaced=False,comma=False,precision=2}
 pound   = Commodity {symbol="£",side=L,spaced=False,comma=False,precision=2}
 hour    = Commodity {symbol="h",side=R,spaced=False,comma=False,precision=1}
 
-dollars  = Amount dollar
+dollars n = Amount dollar n Nothing
-euros    = Amount euro
+euros n   = Amount euro n Nothing
-pounds   = Amount pound
+pounds n  = Amount pound n Nothing
-hours    = Amount hour
+hours n   = Amount hour n Nothing
 
 defaultcommodities = [dollar,  euro,  pound, hour, unknown]
 

Ledger/Parse.hs

@@ -305,17 +305,20 @@ transactionamount :: Parser MixedAmount
 transactionamount =
   try (do
         many1 spacenonewline
-        a <- try leftsymbolamount <|> try rightsymbolamount <|> nosymbolamount <|> return missingamt
+        a <- someamount <|> return missingamt
         return a
       ) <|> return missingamt
 
+someamount = try leftsymbolamount <|> try rightsymbolamount <|> nosymbolamount 
+
 leftsymbolamount :: Parser MixedAmount
 leftsymbolamount = do
   sym <- commoditysymbol 
   sp <- many spacenonewline
   (q,p,comma) <- amountquantity
+  pri <- priceamount
   let c = Commodity {symbol=sym,side=L,spaced=not $ null sp,comma=comma,precision=p}
-  return $ Mixed [Amount c q]
+  return $ Mixed [Amount c q pri]
   <?> "left-symbol amount"
 
 rightsymbolamount :: Parser MixedAmount
@@ -323,20 +326,32 @@ rightsymbolamount = do
   (q,p,comma) <- amountquantity
   sp <- many spacenonewline
   sym <- commoditysymbol
+  pri <- priceamount
   let c = Commodity {symbol=sym,side=R,spaced=not $ null sp,comma=comma,precision=p}
-  return $ Mixed [Amount c q]
+  return $ Mixed [Amount c q pri]
   <?> "right-symbol amount"
 
 nosymbolamount :: Parser MixedAmount
 nosymbolamount = do
   (q,p,comma) <- amountquantity
+  pri <- priceamount
   let c = Commodity {symbol="",side=L,spaced=False,comma=comma,precision=p}
-  return $ Mixed [Amount c q]
+  return $ Mixed [Amount c q pri]
   <?> "no-symbol amount"
 
 commoditysymbol :: Parser String
 commoditysymbol = many1 (noneOf "-.0123456789;\n ") <?> "commodity symbol"
 
+priceamount :: Parser (Maybe MixedAmount)
+priceamount =
+    try (do
+          many spacenonewline
+          char '@'
+          many spacenonewline
+          a <- someamount
+          return $ Just a
+          ) <|> return Nothing
+
 -- gawd.. trying to parse a ledger number without error:
 
 -- | parse a ledger-style numeric quantity and also return the number of

Ledger/RawLedger.hs

@@ -93,7 +93,7 @@ setAmountDisplayPrefs l@(RawLedger ms ps es f) = RawLedger ms ps (map fixEntryAm
       fixEntryAmounts (Entry d s c de co ts pr) = Entry d s c de co (map fixRawTransactionAmounts ts) pr
       fixRawTransactionAmounts (RawTransaction ac a c t) = RawTransaction ac (fixMixedAmount a) c t
       fixMixedAmount (Mixed as) = Mixed $ map fixAmount as
-      fixAmount (Amount c q) = Amount (canonicalcommodity c) q
+      fixAmount (Amount c q pri) = Amount (canonicalcommodity c) q pri
       canonicalcommodity c@(Commodity {symbol=s}) =
           (firstoccurrenceof c){precision=maximum $ map precision $ commoditieswithsymbol s}
       firstoccurrenceof Commodity{symbol=s} = head $ commoditieswithsymbol s

Ledger/Types.hs

@@ -31,7 +31,8 @@ data Commodity = Commodity {
 
 data Amount = Amount {
       commodity :: Commodity,
-      quantity :: Double
+      quantity :: Double,
+      price :: Maybe MixedAmount  -- ^ optional per-unit price for this amount at the time of entry
     } deriving (Eq)
 
 newtype MixedAmount = Mixed [Amount] deriving (Eq)

Tests.hs

@@ -34,15 +34,15 @@ unittests = TestList [
   ,
   "amount arithmetic"   ~: do
     let a1 = dollars 1.23
-    let a2 = Amount (comm "$") (-1.23)
+    let a2 = Amount (comm "$") (-1.23) Nothing
-    let a3 = Amount (comm "$") (-1.23)
+    let a3 = Amount (comm "$") (-1.23) Nothing
-    assertequal (Amount (comm "$") 0) (a1 + a2)
+    assertequal (Amount (comm "$") 0 Nothing) (a1 + a2)
-    assertequal (Amount (comm "$") 0) (a1 + a3)
+    assertequal (Amount (comm "$") 0 Nothing) (a1 + a3)
-    assertequal (Amount (comm "$") (-2.46)) (a2 + a3)
+    assertequal (Amount (comm "$") (-2.46) Nothing) (a2 + a3)
-    assertequal (Amount (comm "$") (-2.46)) (a3 + a3)
+    assertequal (Amount (comm "$") (-2.46) Nothing) (a3 + a3)
-    assertequal (Amount (comm "$") (-2.46)) (sum [a2,a3])
+    assertequal (Amount (comm "$") (-2.46) Nothing) (sum [a2,a3])
-    assertequal (Amount (comm "$") (-2.46)) (sum [a3,a3])
+    assertequal (Amount (comm "$") (-2.46) Nothing) (sum [a3,a3])
-    assertequal (Amount (comm "$") 0) (sum [a1,a2,a3,-a3])
+    assertequal (Amount (comm "$") 0 Nothing) (sum [a1,a2,a3,-a3])
   ,
   "ledgertransaction"  ~: do
     assertparseequal rawtransaction1 (parsewith ledgertransaction rawtransaction1_str)
@@ -78,7 +78,7 @@ unittests = TestList [
   ,
   "transactionamount"       ~: do
     assertparseequal (Mixed [dollars 47.18]) (parsewith transactionamount " $47.18")
-    assertparseequal (Mixed [Amount (Commodity {symbol="$",side=L,spaced=False,comma=False,precision=0}) 1]) (parsewith transactionamount " $1.")
+    assertparseequal (Mixed [Amount (Commodity {symbol="$",side=L,spaced=False,comma=False,precision=0}) 1 Nothing]) (parsewith transactionamount " $1.")
   ,
   "setAmountDisplayPrefs" ~: do
     let l = setAmountDisplayPrefs $ rawLedgerWithAmounts ["1","2.00"]