rename and unify the autofill stuff

Ledger/Entry.hs

@@ -15,6 +15,12 @@ import Ledger.Amount
 
 instance Show Entry where show = showEntry
 
+instance Show ModifierEntry where 
+    show e = "= " ++ (valueexpr e) ++ "\n" ++ unlines (map show (m_transactions e))
+
+instance Show PeriodicEntry where 
+    show e = "~ " ++ (periodexpr e) ++ "\n" ++ unlines (map show (p_transactions e))
+
 {-|
 Show a ledger entry, formatted for the print command. ledger 2.x's
 standard format looks like this:
@@ -53,31 +59,27 @@ showEntry e =
 
 showDate = printf "%-10s"
 
--- | Raise an error if this entry is not balanced.
-assertBalancedEntry :: Entry -> Entry
-assertBalancedEntry e
-    | isEntryBalanced e = e
-    | otherwise = error $ "transactions don't balance in:\n" ++ show e
-
 isEntryBalanced :: Entry -> Bool
 isEntryBalanced (Entry {etransactions=ts}) = isZeroMixedAmount sum
     where
       sum = sumRawTransactions realts
       realts = filter isReal ts
 
--- | Fill in a missing balance in this entry, if there is one, 
--- or raise an error if there is more than one.
-autofillEntry :: Entry -> Entry
-autofillEntry e@(Entry {etransactions=ts}) = e{etransactions=ts'}
-    where ts' = fromMaybe 
-                (error $ "too many missing amounts in this entry, could not auto-balance:\n" ++ show e)
-                (autofillTransactions ts)
-
--- modifier & periodic entries
-
-instance Show ModifierEntry where 
-    show e = "= " ++ (valueexpr e) ++ "\n" ++ unlines (map show (m_transactions e))
-
-instance Show PeriodicEntry where 
-    show e = "~ " ++ (periodexpr e) ++ "\n" ++ unlines (map show (p_transactions e))
-
+-- | Fill in a missing balance in this entry, if we have enough
+-- information to do that. Excluding virtual transactions, there should be
+-- at most one missing balance. Otherwise, raise an error.
+balanceEntry :: Entry -> Entry
+balanceEntry e@(Entry{etransactions=ts}) = e{etransactions=ts'}
+    where 
+      (withamounts, missingamounts) = partition hasAmount $ filter isReal ts
+      ts' = case (length missingamounts) of
+              0 -> ts
+              1 -> map balance ts
+              otherwise -> error $ "could not balance this entry, too many missing amounts:\n" ++ show e
+      otherstotal = sumRawTransactions withamounts
+      simpleotherstotal
+          | length otherstotal == 1 = head otherstotal
+          | otherwise = error $ "sorry, can't balance a mixed-commodity entry yet:\n" ++ show e
+      balance t
+          | isReal t && not (hasAmount t) = t{tamount = -simpleotherstotal}
+          | otherwise = t

Ledger/Parse.hs

@@ -231,7 +231,7 @@ ledgerentry = do
   comment <- ledgercomment
   restofline
   transactions <- ledgertransactions
-  return $ assertBalancedEntry $ autofillEntry $ Entry date status code description comment transactions (unlines preceding)
+  return $ balanceEntry $ Entry date status code description comment transactions (unlines preceding)
 
 ledgerdate :: Parser String
 ledgerdate = do 

Ledger/RawTransaction.hs

@@ -21,26 +21,6 @@ showRawTransaction t = (showaccountname $ taccount t) ++ " " ++ (showamount $ ta
       showaccountname = printf "%-22s" . elideAccountName 22
       showamount = printf "%12s" . showAmountOrZero
 
--- | Fill in the missing balance in an entry's transactions. Excluding
--- virtual transactions, there should be at most one missing balance,
--- otherwise return Nothing.
-autofillTransactions :: [RawTransaction] -> Maybe [RawTransaction]
-autofillTransactions ts =
-    case (length withmissingamounts) of
-      0 -> Just ts
-      1 -> Just $ map balance ts
-      otherwise -> Nothing
-    where 
-      (reals, _) = partition isReal ts
-      (withrealamounts, withmissingamounts) = partition hasAmount reals
-      balance t = if (isReal t) && (not $ hasAmount t) 
-                  then t{tamount = -otherssimpletotal}
-                  else t
-      otherstotal = sumRawTransactions withrealamounts
-      otherssimpletotal
-          | length otherstotal == 1 = head otherstotal
-          | otherwise = error "sorry, can't balance a mixed-commodity entry yet"
-
 isReal :: RawTransaction -> Bool
 isReal t = rttype t == RegularTransaction
 

Tests.hs

@@ -76,10 +76,10 @@ unittests = TestList [
   "ledgerentry"        ~: do
     assertparseequal entry1 (parsewith ledgerentry entry1_str)
   ,
-  "autofillEntry"      ~: do
+  "balanceEntry"      ~: do
     assertequal
       (dollars (-47.18))
-      (tamount $ last $ etransactions $ autofillEntry entry1)
+      (tamount $ last $ etransactions $ balanceEntry entry1)
   ,
   "punctuatethousands"      ~: punctuatethousands "" @?= ""
   ,