try making MixedAmount a full newtype, to avoid TypeSynonymInstances error

BalanceCommand.hs

@@ -131,7 +131,7 @@ showBalanceReport opts args l = acctsstr ++ totalstr
       acctstoshow = balancereportaccts showingsubs apats l
       acctnamestoshow = map aname acctstoshow
       treetoshow = pruneZeroBalanceLeaves $ pruneUnmatchedAccounts $ treeprune maxdepth $ ledgerAccountTree 9999 l
-      total = sumMixedAmounts $ map abalance $ nonredundantaccts
+      total = sum $ map abalance $ nonredundantaccts
       nonredundantaccts = filter (not . hasparentshowing) acctstoshow
       hasparentshowing a = (parentAccountName $ aname a) `elem` acctnamestoshow
 

Ledger/Account.hs

@@ -19,5 +19,5 @@ instance Show Account where
 instance Eq Account where
     (==) (Account n1 t1 b1) (Account n2 t2 b2) = n1 == n2 && t1 == t2 && b1 == b2
 
-nullacct = Account "" [] []
+nullacct = Account "" [] nullamt
 

Ledger/Amount.hs

@@ -45,6 +45,7 @@ import Ledger.Commodity
 
 
 instance Show Amount where show = showAmount
+instance Show MixedAmount where show = showMixedAmount
 
 instance Num Amount where
     abs (Amount c q) = Amount c (abs q)
@@ -55,18 +56,22 @@ instance Num Amount where
     (*) = amountop (*)
 
 instance Num MixedAmount where
+    fromInteger i = Mixed [Amount (comm "") (fromInteger i)]
+    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"
-    fromInteger i = [Amount (comm "") (fromInteger i)]
+
-    negate = map negate
+amounts :: MixedAmount -> [Amount]
-    (+) = (++)
+amounts (Mixed as) = as
-    (*) = error "programming error, mixed amounts do not support multiplication"
 
 showMixedAmount :: MixedAmount -> String
-showMixedAmount as = concat $ intersperse ", " $ map show $ normaliseMixedAmount as
+showMixedAmount m = concat $ intersperse ", " $ map show as
+    where (Mixed as) = normaliseMixedAmount m
 
 normaliseMixedAmount :: MixedAmount -> MixedAmount
-normaliseMixedAmount as = map sumAmounts $ groupAmountsByCommodity as
+normaliseMixedAmount (Mixed as) = Mixed $ map sum $ groupAmountsByCommodity as
 
 groupAmountsByCommodity :: [Amount] -> [[Amount]]
 groupAmountsByCommodity as = grouped
@@ -115,7 +120,7 @@ isZeroAmount a@(Amount c _ ) = nonzerodigits == ""
     where nonzerodigits = filter (`elem` "123456789") $ showAmount a
 
 isZeroMixedAmount :: MixedAmount -> Bool
-isZeroMixedAmount = all isZeroAmount . normaliseMixedAmount
+isZeroMixedAmount = all isZeroAmount . amounts . normaliseMixedAmount
 
 -- | Apply a binary arithmetic operator to two amounts, converting to the
 -- second one's commodity and adopting the lowest precision. (Using the
@@ -130,15 +135,9 @@ amountop op a@(Amount ac aq) b@(Amount bc bq) =
 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
+nullamt :: MixedAmount
--- amount will discard the sum's commodity.
+nullamt = Mixed []
-sumAmounts :: [Amount] -> Amount
-sumAmounts = sum . filter (not . isZeroAmount)
-
-sumMixedAmounts :: [MixedAmount] -> MixedAmount
-sumMixedAmounts = normaliseMixedAmount . concat
-
-nullamt = []
 
 -- temporary value for partial entries
-autoamt = [Amount (Commodity {symbol="AUTO",side=L,spaced=False,comma=False,precision=0,rate=1}) 0]
+autoamt :: MixedAmount
+autoamt = Mixed [Amount (Commodity {symbol="AUTO",side=L,spaced=False,comma=False,precision=0,rate=1}) 0]

Ledger/Entry.hs

@@ -61,7 +61,7 @@ showDate = printf "%-10s"
 
 isEntryBalanced :: Entry -> Bool
 isEntryBalanced (Entry {etransactions=ts}) = 
-    isZeroMixedAmount $ sumMixedAmounts $ map tamount $ filter isReal ts
+    isZeroMixedAmount $ sum $ map tamount $ filter isReal ts
 
 -- | Fill in a missing balance in this entry, if we have enough
 -- information to do that. Excluding virtual transactions, there should be
@@ -74,7 +74,7 @@ balanceEntry e@(Entry{etransactions=ts}) = e{etransactions=ts'}
               0 -> ts
               1 -> map balance ts
               otherwise -> error $ "could not balance this entry, too many missing amounts:\n" ++ show e
-      otherstotal = sumMixedAmounts $ map tamount withamounts
+      otherstotal = sum $ map tamount withamounts
       balance t
           | isReal t && not (hasAmount t) = t{tamount = -otherstotal}
           | otherwise = t

Ledger/Ledger.hs

@@ -45,7 +45,7 @@ cacheLedger l = Ledger l ant amap
       subtxnsof a = concat [txnsof a | a <- [a] ++ subacctsof a]
       balmap = Map.union 
                (Map.fromList [(a,(sumTransactions $ subtxnsof a)) | a <- anames])
-               (Map.fromList [(a,[]) | a <- anames])
+               (Map.fromList [(a,Mixed []) | a <- anames])
       amap = Map.fromList [(a, Account a (txnmap ! a) (balmap ! a)) | a <- anames]
 
 -- | List a ledger's account names.

Ledger/Parse.hs

@@ -315,7 +315,7 @@ leftsymbolamount = do
   sp <- many spacenonewline
   (q,p,comma) <- amountquantity
   let c = Commodity {symbol=sym,side=L,spaced=not $ null sp,comma=comma,precision=p,rate=1}
-  return [Amount c q]
+  return $ Mixed [Amount c q]
   <?> "left-symbol amount"
 
 rightsymbolamount :: Parser MixedAmount
@@ -324,14 +324,14 @@ rightsymbolamount = do
   sp <- many spacenonewline
   sym <- commoditysymbol
   let c = Commodity {symbol=sym,side=R,spaced=not $ null sp,comma=comma,precision=p,rate=1}
-  return [Amount c q]
+  return $ Mixed [Amount c q]
   <?> "right-symbol amount"
 
 nosymbolamount :: Parser MixedAmount
 nosymbolamount = do
   (q,p,comma) <- amountquantity
   let c = Commodity {symbol="",side=L,spaced=False,comma=comma,precision=p,rate=1}
-  return [Amount c q]
+  return $ Mixed [Amount c q]
   <?> "no-symbol amount"
 
 commoditysymbol :: Parser String

Ledger/RawLedger.hs

@@ -100,7 +100,7 @@ normaliseRawLedgerAmounts l@(RawLedger ms ps es f) = RawLedger ms ps es' f
       normaliseRawTransactionAmounts (RawTransaction acct a c t) = RawTransaction acct a' c t
           where a' = normaliseMixedAmount a
       firstcommodities = nubBy samesymbol $ allcommodities
-      allcommodities = map commodity $ concat $ map amount $ rawLedgerTransactions l
+      allcommodities = map commodity $ concat $ map (amounts . amount) $ rawLedgerTransactions l
       samesymbol (Commodity {symbol=s1}) (Commodity {symbol=s2}) = s1==s2
       firstoccurrenceof c@(Commodity {symbol=s}) = 
           fromMaybe

Ledger/TimeLog.hs

@@ -57,7 +57,7 @@ entryFromTimeLogInOut i o =
       showdate = formatTime defaultTimeLocale "%Y/%m/%d"
       intime   = parsedatetime $ tldatetime i
       outtime  = parsedatetime $ tldatetime o
-      amount   = [hours $ realToFrac (diffUTCTime outtime intime) / 3600]
+      amount   = Mixed [hours $ realToFrac (diffUTCTime outtime intime) / 3600]
       txns     = [RawTransaction acctname amount "" RegularTransaction
                  --,RawTransaction "assets:time" (-amount) "" RegularTransaction
                  ]

Ledger/Transaction.hs

@@ -30,6 +30,6 @@ accountNamesFromTransactions :: [Transaction] -> [AccountName]
 accountNamesFromTransactions ts = nub $ map account ts
 
 sumTransactions :: [Transaction] -> MixedAmount
-sumTransactions = sumMixedAmounts . map amount
+sumTransactions = sum . map amount
 
 nulltxn = Transaction 0 "" "" "" nullamt RegularTransaction

Ledger/Types.hs

@@ -15,6 +15,8 @@ type Date = String
 
 type DateTime = String
 
+type AccountName = String
+
 data Side = L | R deriving (Eq,Show) 
 
 data Commodity = Commodity {
@@ -34,9 +36,7 @@ data Amount = Amount {
       quantity :: Double
     } deriving (Eq)
 
-type MixedAmount = [Amount]
+newtype MixedAmount = Mixed [Amount] deriving (Eq)
-
-type AccountName = String
 
 data TransactionType = RegularTransaction | VirtualTransaction | BalancedVirtualTransaction
                        deriving (Eq,Show)

Tests.hs

@@ -78,7 +78,7 @@ unittests = TestList [
   ,
   "balanceEntry"      ~: do
     assertequal
-      [dollars (-47.18)]
+      (Mixed [dollars (-47.18)])
       (tamount $ last $ etransactions $ balanceEntry entry1)
   ,
   "punctuatethousands"      ~: punctuatethousands "" @?= ""
@@ -103,8 +103,8 @@ unittests = TestList [
     assertequal 15 (length $ Map.keys $ accountmap $ cacheLedger rawledger7)
   ,
   "transactionamount"       ~: do
-    assertparseequal [dollars 47.18] (parsewith transactionamount " $47.18")
+    assertparseequal (Mixed [dollars 47.18]) (parsewith transactionamount " $47.18")
-    assertparseequal [Amount (Commodity {symbol="$",side=L,spaced=False,comma=False,precision=0,rate=1}) 1] (parsewith transactionamount " $1.")
+    assertparseequal (Mixed [Amount (Commodity {symbol="$",side=L,spaced=False,comma=False,precision=0,rate=1}) 1]) (parsewith transactionamount " $1.")
   ]
 
 ------------------------------------------------------------------------------
@@ -243,7 +243,7 @@ assertparseequal expected parsed = either printParseError (assertequal expected)
 
 rawtransaction1_str  = "  expenses:food:dining  $10.00\n"
 
-rawtransaction1 = RawTransaction "expenses:food:dining" [dollars 10] "" RegularTransaction
+rawtransaction1 = RawTransaction "expenses:food:dining"(Mixed  [dollars 10]) "" RegularTransaction
 
 entry1_str = "\
 \2007/01/28 coopportunity\n\
@@ -253,8 +253,8 @@ entry1_str = "\
 
 entry1 =
     (Entry "2007/01/28" False "" "coopportunity" ""
-     [RawTransaction "expenses:food:groceries" [dollars 47.18] "" RegularTransaction, 
+     [RawTransaction "expenses:food:groceries" (Mixed [dollars 47.18]) "" RegularTransaction, 
-      RawTransaction "assets:checking" [dollars (-47.18)] "" RegularTransaction] "")
+      RawTransaction "assets:checking" (Mixed [dollars (-47.18)]) "" RegularTransaction] "")
 
 
 entry2_str = "\
@@ -398,13 +398,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="assets:cash", 
-                tamount=[dollars 4.82],
+                tamount=(Mixed [dollars 4.82]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="equity:opening balances", 
-                tamount=[dollars (-4.82)],
+                tamount=(Mixed [dollars (-4.82)]),
                 tcomment="",
                 rttype=RegularTransaction
               }
@@ -421,13 +421,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="expenses:vacation", 
-                tamount=[dollars 179.92],
+                tamount=(Mixed [dollars 179.92]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="assets:checking", 
-                tamount=[dollars (-179.92)],
+                tamount=(Mixed [dollars (-179.92)]),
                 tcomment="",
                 rttype=RegularTransaction
               }
@@ -444,13 +444,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="assets:saving", 
-                tamount=[dollars 200],
+                tamount=(Mixed [dollars 200]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="assets:checking", 
-                tamount=[dollars (-200)],
+                tamount=(Mixed [dollars (-200)]),
                 tcomment="",
                 rttype=RegularTransaction
               }
@@ -467,13 +467,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="expenses:food:dining", 
-                tamount=[dollars 4.82],
+                tamount=(Mixed [dollars 4.82]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="assets:cash", 
-                tamount=[dollars (-4.82)],
+                tamount=(Mixed [dollars (-4.82)]),
                 tcomment="",
                 rttype=RegularTransaction
               }
@@ -490,13 +490,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="expenses:phone", 
-                tamount=[dollars 95.11],
+                tamount=(Mixed [dollars 95.11]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="assets:checking", 
-                tamount=[dollars (-95.11)],
+                tamount=(Mixed [dollars (-95.11)]),
                 tcomment="",
                 rttype=RegularTransaction
               }
@@ -513,13 +513,13 @@ rawledger7 = RawLedger
              etransactions=[
               RawTransaction {
                 taccount="liabilities:credit cards:discover", 
-                tamount=[dollars 80],
+                tamount=(Mixed [dollars 80]),
                 tcomment="",
                 rttype=RegularTransaction
               },
               RawTransaction {
                 taccount="assets:checking", 
-                tamount=[dollars (-80)],
+                tamount=(Mixed [dollars (-80)]),
                 tcomment="",
                 rttype=RegularTransaction
               }