ledger: handle errors better in the ledger reader

hledger-lib/Hledger/Read/LedgerReader.hs

@@ -33,7 +33,7 @@ import Test.HUnit
 -- import Test.Framework
 -- import Text.Megaparsec.Error
 -- #endif
--- import Text.Megaparsec hiding (parse)
+import Text.Megaparsec (eof)
 -- import Text.Printf
 import System.FilePath
 import System.Time
@@ -75,14 +75,21 @@ parse _mrulespath assrt path txt = do
     Failure ei -> throwError $ show ei
     Success res -> do
       -- dbg7IO "raw entities" res
-      pj <- liftIO $ foldM journalAddRawEntityInSitu nulljournal res
+      ejus <- liftIO $ sequence <$> mapM rawEntityInSituToJournalUpdate res
+      case ejus of
+        Left err  -> throwError err
+        Right jus -> do
+          let pj = foldr (flip (.)) id jus nulljournal
           t <- liftIO getClockTime
           either throwError return $ journalFinalise t path txt assrt pj
 
-journalAddRawEntityInSitu :: ParsedJournal -> RawEntityInSitu -> IO ParsedJournal
-journalAddRawEntityInSitu
-  j
-  RawEntityInSitu{rawEntity=RawTransactionEntity (rt@RawTransaction{
+-- (I'm not too fond of journal update functions, but ok..)
+-- | Convert a ledger4 RawEntityInSitu - representing a parsed transaction,
+-- directive, comment etc. - into either a journal update function or an error.
+-- Currently converts only transactions, and ignores some transaction fields.
+-- Runs in IO because it uses some hledger parsers that have some need for that.
+rawEntityInSituToJournalUpdate :: RawEntityInSitu -> IO (Either String (ParsedJournal -> ParsedJournal))
+rawEntityInSituToJournalUpdate RawEntityInSitu{rawEntity=RawTransactionEntity (rt@RawTransaction{
     rawTxnDate    = date     -- :: !String
   , rawTxnDateAux = mdate2   -- :: Maybe String
   , rawTxnState   = _mstatus -- :: Maybe Char
@@ -92,12 +99,23 @@ journalAddRawEntityInSitu
   , rawTxnPosts   = rps      -- :: ![RawPosting]
   })}
   = do
-    ps <- catMaybes <$> mapM rawPostingToPosting rps
+    let md = parsedateM date
+        md2 = mdate2 >>= parsedateM
+        dateerr = return . Left . ("could not parse date "++)
+    case (md, mdate2, md2) of
+      (Nothing, _, _)          -> dateerr date
+      (_, Just date2, Nothing) -> dateerr date2
+      (Just d, _, _)           -> do
+        eps <- sequence . catMaybes <$> mapM rawPostingToPosting rps
+        case eps of
+          Left err -> return $ Left err
+          Right ps -> do
             let t = nulltransaction{
+              -- XXX TODO more complete transaction parsing
               -- tindex                   -- :: Integer,   -- ^ this transaction's 1-based position in the input stream, or 0 when not available
               -- tsourcepos               -- :: GenericSourcePos,
-        tdate = parsedate date -- XXX                   -- :: Day,
-      , tdate2 = parsedate <$> mdate2 -- XXX                  -- :: Maybe Day,
+                tdate = d                 -- :: Day
+              , tdate2 = md2              -- :: Maybe Day
               -- tstatus                  -- :: ClearedStatus,
               -- tcode                    -- :: Text,
               , tdescription = pack desc  -- :: Text,
@@ -108,22 +126,26 @@ journalAddRawEntityInSitu
               }
             dbg7IO "raw transaction" rt
             dbg7IO "cooked transaction" t
-    return $ addTransaction t j
+            return $ Right $ addTransaction t
+-- TODO convert other entities
+rawEntityInSituToJournalUpdate _ = return $ Right id
 
-journalAddRawEntityInSitu j _ = return j
-
-rawPostingToPosting :: RawPosting -> IO (Maybe Posting)
+-- | Convert a ledger4 RawPosting to a hledger Posting or an error message.
+-- Currently ignores some posting fields, and the RawPostingNote variant
+-- (which represents a comment line, not a posting; returns Nothing for these).
+rawPostingToPosting :: RawPosting -> IO (Maybe (Either String Posting))
 rawPostingToPosting RawPosting{
+    -- TODO
     rawPostState   = _mstatus -- :: Maybe Char
   , rawPostAccount = acct     -- :: !String
   , rawPostAmount  = mamtstr  -- :: Maybe String
   , rawPostNote    = _mnote   -- :: Maybe String
   } = do
-    eamt <- runErroringJournalParser spaceandamountormissingp $ pack $ maybe "" (' ':) mamtstr
+    eamt <- runErroringJournalParser (spaceandamountormissingp <* eof) $ pack $ maybe "" (' ':) mamtstr
     case eamt of
-      Left _err -> return Nothing -- XXX should throw error
+      Left err -> return $ Just $ Left err
       Right (amt :: MixedAmount) -> do
-        return $ Just nullposting{
+        return $ Just $ Right nullposting{
         --   pdate             -- :: Maybe Day,         -- ^ this posting's date, if different from the transaction's
         -- , pdate2            -- :: Maybe Day,         -- ^ this posting's secondary date, if different from the transaction's
         -- , pstatus           -- :: ClearedStatus,
@@ -137,7 +159,8 @@ rawPostingToPosting RawPosting{
         }
 rawPostingToPosting (RawPostingNote _) = return Nothing
 
--- raw parse example:
+
+-- A raw parse example:
 --
 -- 2010/01/01 * T1
 --     Accounts:Hub    30.00 USD
@@ -162,10 +185,7 @@ rawPostingToPosting (RawPostingNote _) = return Nothing
 -- ]
 
 
-
-
 --- * hunit tests
 
 tests_Hledger_Read_LedgerReader = TestList $ concat [
-    -- test_numberp
  ]