lib: number transactions as they are read

And allow looking up transactions by their read order (index),
or the previous/next transactions in the sequence.

hledger-lib/Hledger/Data/Journal.hs

@@ -35,6 +35,9 @@ module Hledger.Data.Journal (
   journalDescriptions,
   journalFilePath,
   journalFilePaths,
+  journalTransactionAt,
+  journalNextTransaction,
+  journalPrevTransaction,
   journalPostings,
   -- * Standard account types
   journalBalanceSheetAccountQuery,
@@ -134,7 +137,7 @@ nulljournal = Journal { jmodifiertxns = []
                       }
 
 nullctx :: JournalContext
-nullctx = Ctx { ctxYear = Nothing, ctxDefaultCommodityAndStyle = Nothing, ctxAccount = [], ctxAliases = [] }
+nullctx = Ctx{ctxYear=Nothing, ctxDefaultCommodityAndStyle=Nothing, ctxAccount=[], ctxAliases=[], ctxTransactionIndex=0}
 
 journalFilePath :: Journal -> FilePath
 journalFilePath = fst . mainfile
@@ -160,6 +163,20 @@ addMarketPrice h j = j { jmarketprices = h : jmarketprices j }
 addTimeLogEntry :: TimeLogEntry -> Journal -> Journal
 addTimeLogEntry tle j = j { open_timelog_entries = tle : open_timelog_entries j }
 
+-- | Get the transaction with this index (its 1-based position in the input stream), if any.
+journalTransactionAt :: Journal -> Integer -> Maybe Transaction
+journalTransactionAt Journal{jtxns=ts} i =
+  -- it's probably ts !! (i+1), but we won't assume
+  headMay [t | t <- ts, tindex t == i]
+
+-- | Get the transaction that appeared immediately after this one in the input stream, if any.
+journalNextTransaction :: Journal -> Transaction -> Maybe Transaction
+journalNextTransaction j t = journalTransactionAt j (tindex t + 1)
+  
+-- | Get the transaction that appeared immediately before this one in the input stream, if any.
+journalPrevTransaction :: Journal -> Transaction -> Maybe Transaction
+journalPrevTransaction j t = journalTransactionAt j (tindex t - 1)
+  
 -- | Unique transaction descriptions used in this journal.
 journalDescriptions :: Journal -> [String]
 journalDescriptions = nub . sort . map tdescription . jtxns
@@ -683,6 +700,7 @@ Right samplejournal = journalBalanceTransactions $
          nulljournal
          {jtxns = [
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/01/01",
              tdate2=Nothing,
@@ -699,6 +717,7 @@ Right samplejournal = journalBalanceTransactions $
            }
           ,
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/06/01",
              tdate2=Nothing,
@@ -715,6 +734,7 @@ Right samplejournal = journalBalanceTransactions $
            }
           ,
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/06/02",
              tdate2=Nothing,
@@ -731,6 +751,7 @@ Right samplejournal = journalBalanceTransactions $
            }
           ,
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/06/03",
              tdate2=Nothing,
@@ -747,6 +768,7 @@ Right samplejournal = journalBalanceTransactions $
            }
           ,
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/12/31",
              tdate2=Nothing,

hledger-lib/Hledger/Data/TimeLog.hs

@@ -79,6 +79,7 @@ entryFromTimeLogInOut i o
         error' $ "clock-out time less than clock-in time in:\n" ++ showTransaction t
     where
       t = Transaction {
+            tindex       = 0,
             tsourcepos   = tlsourcepos i,
             tdate        = idate,
             tdate2       = Nothing,

hledger-lib/Hledger/Data/Transaction.hs

@@ -61,6 +61,7 @@ nullsourcepos = GenericSourcePos "" 1 1
 
 nulltransaction :: Transaction
 nulltransaction = Transaction {
+                    tindex=0,
                     tsourcepos=nullsourcepos,
                     tdate=nulldate,
                     tdate2=Nothing,
@@ -419,7 +420,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,"    assets:checking"
         ,""
         ])
-       (let t = Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
+       (let t = Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
                 [posting{paccount="expenses:food:groceries", pamount=Mixed [usd 47.18], ptransaction=Just t}
                 ,posting{paccount="assets:checking", pamount=Mixed [usd (-47.18)], ptransaction=Just t}
                 ] ""
@@ -433,7 +434,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,"    assets:checking               $-47.18"
         ,""
         ])
-       (let t = Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
+       (let t = Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
                 [posting{paccount="expenses:food:groceries", pamount=Mixed [usd 47.18], ptransaction=Just t}
                 ,posting{paccount="assets:checking", pamount=Mixed [usd (-47.18)], ptransaction=Just t}
                 ] ""
@@ -449,7 +450,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,""
         ])
        (showTransaction
-        (txnTieKnot $ Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
+        (txnTieKnot $ Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
          [posting{paccount="expenses:food:groceries", pamount=Mixed [usd 47.18]}
          ,posting{paccount="assets:checking", pamount=Mixed [usd (-47.19)]}
          ] ""))
@@ -462,7 +463,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,""
         ])
        (showTransaction
-        (txnTieKnot $ Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
+        (txnTieKnot $ Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
          [posting{paccount="expenses:food:groceries", pamount=Mixed [usd 47.18]}
          ] ""))
 
@@ -474,7 +475,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,""
         ])
        (showTransaction
-        (txnTieKnot $ Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
+        (txnTieKnot $ Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "coopportunity" "" []
          [posting{paccount="expenses:food:groceries", pamount=missingmixedamt}
          ] ""))
 
@@ -487,7 +488,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
         ,""
         ])
        (showTransaction
-        (txnTieKnot $ Transaction nullsourcepos (parsedate "2010/01/01") Nothing Uncleared "" "x" "" []
+        (txnTieKnot $ Transaction 0 nullsourcepos (parsedate "2010/01/01") Nothing Uncleared "" "x" "" []
          [posting{paccount="a", pamount=Mixed [num 1 `at` (usd 2 `withPrecision` 0)]}
          ,posting{paccount="b", pamount= missingmixedamt}
          ] ""))
@@ -495,19 +496,19 @@ tests_Hledger_Data_Transaction = TestList $ concat [
   ,"balanceTransaction" ~: do
      assertBool "detect unbalanced entry, sign error"
                     (isLeft $ balanceTransaction Nothing
-                           (Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "test" "" []
+                           (Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "test" "" []
                             [posting{paccount="a", pamount=Mixed [usd 1]}
                             ,posting{paccount="b", pamount=Mixed [usd 1]}
                             ] ""))
 
      assertBool "detect unbalanced entry, multiple missing amounts"
                     (isLeft $ balanceTransaction Nothing
-                           (Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "test" "" []
+                           (Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "test" "" []
                             [posting{paccount="a", pamount=missingmixedamt}
                             ,posting{paccount="b", pamount=missingmixedamt}
                             ] ""))
 
-     let e = balanceTransaction Nothing (Transaction nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "" "" []
+     let e = balanceTransaction Nothing (Transaction 0 nullsourcepos (parsedate "2007/01/28") Nothing Uncleared "" "" "" []
                            [posting{paccount="a", pamount=Mixed [usd 1]}
                            ,posting{paccount="b", pamount=missingmixedamt}
                            ] "")
@@ -518,7 +519,7 @@ tests_Hledger_Data_Transaction = TestList $ concat [
                         Right e' -> (pamount $ last $ tpostings e')
                         Left _ -> error' "should not happen")
 
-     let e = balanceTransaction Nothing (Transaction nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
+     let e = balanceTransaction Nothing (Transaction 0 nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
                            [posting{paccount="a", pamount=Mixed [usd 1.35]}
                            ,posting{paccount="b", pamount=Mixed [eur (-1)]}
                            ] "")
@@ -530,49 +531,49 @@ tests_Hledger_Data_Transaction = TestList $ concat [
                         Left _ -> error' "should not happen")
 
      assertBool "balanceTransaction balances based on cost if there are unit prices" (isRight $
-       balanceTransaction Nothing (Transaction nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
+       balanceTransaction Nothing (Transaction 0 nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
                            [posting{paccount="a", pamount=Mixed [usd 1 `at` eur 2]}
                            ,posting{paccount="a", pamount=Mixed [usd (-2) `at` eur 1]}
                            ] ""))
 
      assertBool "balanceTransaction balances based on cost if there are total prices" (isRight $
-       balanceTransaction Nothing (Transaction nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
+       balanceTransaction Nothing (Transaction 0 nullsourcepos (parsedate "2011/01/01") Nothing Uncleared "" "" "" []
                            [posting{paccount="a", pamount=Mixed [usd 1    @@ eur 1]}
                            ,posting{paccount="a", pamount=Mixed [usd (-2) @@ eur 1]}
                            ] ""))
 
   ,"isTransactionBalanced" ~: do
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ,posting{paccount="c", pamount=Mixed [usd (-1.00)], ptransaction=Just t}
              ] ""
      assertBool "detect balanced" (isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ,posting{paccount="c", pamount=Mixed [usd (-1.01)], ptransaction=Just t}
              ] ""
      assertBool "detect unbalanced" (not $ isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ] ""
      assertBool "detect unbalanced, one posting" (not $ isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 0], ptransaction=Just t}
              ] ""
      assertBool "one zero posting is considered balanced for now" (isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ,posting{paccount="c", pamount=Mixed [usd (-1.00)], ptransaction=Just t}
              ,posting{paccount="d", pamount=Mixed [usd 100], ptype=VirtualPosting, ptransaction=Just t}
              ] ""
      assertBool "virtual postings don't need to balance" (isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ,posting{paccount="c", pamount=Mixed [usd (-1.00)], ptransaction=Just t}
              ,posting{paccount="d", pamount=Mixed [usd 100], ptype=BalancedVirtualPosting, ptransaction=Just t}
              ] ""
      assertBool "balanced virtual postings need to balance among themselves" (not $ isTransactionBalanced Nothing t)
-     let t = Transaction nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
+     let t = Transaction 0 nullsourcepos (parsedate "2009/01/01") Nothing Uncleared "" "a" "" []
              [posting{paccount="b", pamount=Mixed [usd 1.00], ptransaction=Just t}
              ,posting{paccount="c", pamount=Mixed [usd (-1.00)], ptransaction=Just t}
              ,posting{paccount="d", pamount=Mixed [usd 100], ptype=BalancedVirtualPosting, ptransaction=Just t}

hledger-lib/Hledger/Data/Types.hs

@@ -170,6 +170,7 @@ data GenericSourcePos = GenericSourcePos FilePath Int Int
 instance NFData GenericSourcePos
 
 data Transaction = Transaction {
+      tindex :: Integer, -- ^ this transaction's 1-based position in the input stream, or 0 when not available
       tsourcepos :: GenericSourcePos,
       tdate :: Day,
       tdate2 :: Maybe Day,
@@ -233,6 +234,7 @@ data JournalContext = Ctx {
                                         --   specified with "account" directive(s). Concatenated, these
                                         --   are the account prefix prepended to parsed account names.
     , ctxAliases   :: ![AccountAlias]   -- ^ the current list of account name aliases in effect
+    , ctxTransactionIndex   :: !Integer -- ^ the number of transactions read so far
     } deriving (Read, Show, Eq, Data, Typeable, Generic)
 
 instance NFData JournalContext

hledger-lib/Hledger/Read/JournalReader.hs

@@ -212,6 +212,12 @@ getAccountAliases = liftM ctxAliases getState
 clearAccountAliases :: Stream [Char] m Char => ParsecT [Char] JournalContext m ()
 clearAccountAliases = modifyState (\(ctx@Ctx{..}) -> ctx{ctxAliases=[]})
 
+getIndex :: Stream [Char] m Char => ParsecT s JournalContext m Integer
+getIndex = liftM ctxTransactionIndex getState
+
+setIndex :: Stream [Char] m Char => Integer -> ParsecT [Char] JournalContext m ()
+setIndex i = modifyState (\ctx -> ctx{ctxTransactionIndex=i})
+
 -- parsers
 
 -- | Top-level journal parser. Returns a single composite, I/O performing,
@@ -437,7 +443,9 @@ transactionp = do
   comment <- try followingcommentp <|> (newline >> return "")
   let tags = tagsInComment comment
   postings <- postingsp
-  return $ txnTieKnot $ Transaction sourcepos date edate status code description comment tags postings ""
+  index <- getIndex
+  setIndex (index+1)
+  return $ txnTieKnot $ Transaction index sourcepos date edate status code description comment tags postings ""
 
 descriptionp = many (noneOf ";\n")
 

hledger-lib/Hledger/Reports/BalanceReport.hs

@@ -368,6 +368,7 @@ Right samplejournal2 = journalBalanceTransactions $
          nulljournal
          {jtxns = [
            txnTieKnot $ Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2008/01/01",
              tdate2=Just $ parsedate "2009/01/01",

hledger/Hledger/Cli.hs

@@ -343,6 +343,7 @@ journal7 :: Journal
 journal7 = nulljournal {jtxns =
           [
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/01/01",
              tdate2=Nothing,
@@ -359,6 +360,7 @@ journal7 = nulljournal {jtxns =
            }
           ,
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/02/01",
              tdate2=Nothing,
@@ -375,6 +377,7 @@ journal7 = nulljournal {jtxns =
            }
           ,
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/01/02",
              tdate2=Nothing,
@@ -391,6 +394,7 @@ journal7 = nulljournal {jtxns =
            }
           ,
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/01/03",
              tdate2=Nothing,
@@ -407,6 +411,7 @@ journal7 = nulljournal {jtxns =
            }
           ,
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/01/03",
              tdate2=Nothing,
@@ -423,6 +428,7 @@ journal7 = nulljournal {jtxns =
            }
           ,
            txnTieKnot Transaction {
+             tindex=0,
              tsourcepos=nullsourcepos,
              tdate=parsedate "2007/01/03",
              tdate2=Nothing,