a partly-working parser for the ledger file format

hledger.hs

@@ -1,26 +1,230 @@
--- ledger-compatible money management tools
+-- hledger - ledger-like money management utilities
--- (c) 2007 Simon Michael & contributors, released under GPL v3 or later
+-- GPLv3, (c) Simon Michael & contributors, 
+-- ledger is at http://newartisans.com/ledger.html
 
+import System.Directory (getHomeDirectory)
+import System.Environment (getEnv)
 import Control.Exception (assert)
-
+import Text.ParserCombinators.Parsec
--- data model
+import qualified Text.ParserCombinators.Parsec.Token as P
-type Date = String
+import Text.ParserCombinators.Parsec.Language (haskellDef)
-type Account = String
+--import TildeExpand -- confuses my ghc 6.7
-type Money = Float
--- a transaction records a movement of money between two accounts
-data Transaction = Transaction {
-                                date :: Date,
-                                account :: Account,       -- debit this
-                                other_account :: Account, -- credit this
-                                description :: String,
-                                amount :: Money
-                               }
 
 -- sample data
-t1 = Transaction "2007-01-01" "checking" "food" "joe's diner" 8.50
 
--- tests
+sample_entry = "\
+\2007/01/27 * joes diner\n\
+\  expenses:food:dining                    $10.00\n\
+\  expenses:gifts                          $10.00\n\
+\  assets:checking                        $-20.00\n\
+\\n\" --"
+
+sample_entry2 = "\
+\2007/01/28 coopportunity\n\
+\  expenses:food:groceries                 $47.18\n\
+\  assets:checking\n\
+\\n" --"
+
+sample_periodic_entry = "\
+\~ monthly from 2007/2/2\n\
+\  assets:saving            $200.00\n\
+\  assets:checking\n\
+\\n" --"
+
+sample_periodic_entry2 = "\
+\~ monthly from 2007/2/2\n\
+\  assets:saving            $200.00         ;auto savings\n\
+\  assets:checking\n\
+\\n" --"
+
+sample_transaction  = "  expenses:food:dining $10.00\n"
+
+sample_transaction2 = "  assets:checking\n"
+
+sample_ledger = "\
+\\n\
+\2007/01/27 * joes diner\n\
+\  expenses:food:dining                    $10.00\n\
+\  expenses:gifts                          $10.00\n\
+\  assets:checking                        $-20.00\n\
+\\n\
+\\n\
+\2007/01/28 coopportunity\n\
+\  expenses:food:groceries                 $47.18\n\
+\  assets:checking                        $-47.18\n\
+\\n\
+\" --"
+
+sample_ledger2 = "\
+\;comment\n\
+\2007/01/27 * joes diner\n\
+\  expenses:food:dining                    $10.00\n\
+\  assets:checking                        $-47.18\n\
+\\n" --"
+
+sample_ledger3 = "\
+\2007/01/27 * joes diner\n\
+\  expenses:food:dining                    $10.00\n\
+\;intra-entry comment\n\
+\  assets:checking                        $-47.18\n\
+\\n" --"
+
+sample_ledger4 = "\
+\!include \"somefile\"\n\
+\2007/01/27 * joes diner\n\
+\  expenses:food:dining                    $10.00\n\
+\  assets:checking                        $-47.18\n\
+\\n" --"
+
+sample_ledger5 = ""
+
+-- a data model
+
+data Ledger = Ledger {
+                      modifier_entries :: [ModifierEntry],
+                      periodic_entries :: [PeriodicEntry],
+                      entries :: [Entry]
+                     } deriving (Show, Eq)
+data Entry = Entry {
+                    date :: Date,
+                    status :: Bool,
+                    code :: String,
+                    description :: String,
+                    transactions :: [Transaction]
+                   } deriving (Show, Eq)
+data ModifierEntry = ModifierEntry {
+                    valueexpr :: String,
+                    m_transactions :: [Transaction]
+                   } deriving (Show, Eq)
+data PeriodicEntry = PeriodicEntry {
+                    periodexpr :: String,
+                    p_transactions :: [Transaction]
+                   } deriving (Show, Eq)
+data Transaction = Transaction {
+                                account :: Account,
+                                amount :: Amount
+                               } deriving (Show, Eq)
+data Amount = Amount {
+                      currency :: String,
+                      quantity :: Float
+                     } deriving (Read, Show, Eq)
+type Date = String
+type Account = String
+
+-- ledger file parsing
+
+ledger = do
+  ledgernondatalines
+  -- unlike ledger these must be first for now
+  modifier_entries <- many ledgermodifierentry
+  periodic_entries <- many ledgerperiodicentry
+  --
+  entries <- (many ledgerentry) <?> "entry"
+  eof
+  return (Ledger modifier_entries periodic_entries entries)
+
+ledgernondatalines = many (ledgercomment <|> ledgerdirective <|> do {space; return []})
+
+ledgercomment = char ';' >> anyChar `manyTill` newline <?> "comment"
+
+ledgerdirective = char '!' >> anyChar `manyTill` newline <?> "directive"
+
+ledgermodifierentry = do
+  ledgernondatalines
+  char '=' <?> "entry"
+  valueexpr <- anyChar `manyTill` newline
+  transactions <- (ledgertransaction <?> "transaction") `manyTill` (newline <?> "blank line")
+  spaces
+  return (ModifierEntry valueexpr transactions)
+
+ledgerperiodicentry = do
+  ledgernondatalines
+  char '~' <?> "entry"
+  periodexpr <- anyChar `manyTill` newline
+  transactions <- (ledgertransaction <?> "transaction") `manyTill` (newline <?> "blank line")
+  spaces
+  return (PeriodicEntry periodexpr transactions)
+
+ledgerentry = do
+  ledgernondatalines
+  date <- ledgerdate
+  many1 spacenonewline
+  status <- ledgerstatus
+  code <- ledgercode
+  description <- anyChar `manyTill` ledgereol
+  transactions <- (ledgertransaction <?> "transaction") `manyTill` (newline <?> "blank line")
+                  -- unlike ledger, we need the file to end with a blank line
+  spaces
+  return (Entry date status code description transactions)
+
+ledgerdate = many1 (digit <|> char '/')
+
+ledgerstatus = try (do { char '*'; many1 spacenonewline; return True } ) <|> return False
+
+ledgercode = try (do { char '('; code <- anyChar `manyTill` char ')'; return code } ) <|> return ""
+
+ledgertransaction = do
+  many (ledgercomment <|> ledgerdirective)
+  many1 spacenonewline
+  account <- ledgeraccount <?> "account"
+  amount <- ledgeramount <?> "amount"
+  return (Transaction account amount)
+
+--ledgeraccount = do {alphaNum; many (alphaNum <|> char ':' <|> try (do {spacenonewline; notFollowedBy spacenonewline; return ' '}))}
+ledgeraccount = many1 (alphaNum <|> char ':' <|> try (do {spacenonewline; do {notFollowedBy spacenonewline; return ' '}}))
+
+twoormorespaces = do spacenonewline; many1 spacenonewline
+
+ledgeramount = try (do
+                      many1 spacenonewline --twoormorespaces
+                      currency <- many (noneOf "-.0123456789\n") <?> "currency"
+                      quantity <- (oneOf "-.0123456789") `manyTill` ledgereol <?> "quantity"
+                      return (Amount currency (read quantity))
+                   ) <|> do
+                      ledgereol
+                      return (Amount "" 0) -- change later to balance entry
+
+ledgereol = do {newline; return []} <|> ledgercomment
+
+spacenonewline = satisfy (\c -> c `elem` " \v\f\t")
+
+-- run tests
+
+parseMyLedgerFile = do
+  fname <- ledgerFilePath
+  parsed <- parseFromFile ledger fname
+  return parsed
+    where
+      ledgerFilePath = do
+                      filepath <- getEnv "LEDGER" `catch` \_ -> return "ledger.dat"
+                      -- don't know how to accomplish this great feat
+                      --ledger_file <- tildeExpand filepath
+                      let ledger_file = filepath
+                      return ledger_file
+
 main = do
-  assert_ $ amount t1 == 8.50
+  showParseResult (parse ledgertransaction "" sample_transaction)
-  putStrLn "ok"
+  showParseResult (parse ledgertransaction "" sample_transaction2)
-    where assert_ e = assert e return ()             
+  showParseResult (parse ledgerentry "" sample_entry)
+  showParseResult (parse ledgerentry "" sample_entry2)
+  showParseResult (parse ledgerperiodicentry "" sample_periodic_entry)
+  showParseResult (parse ledgerperiodicentry "" sample_periodic_entry2)
+  showParseResult (parse ledger "" sample_ledger)
+  showParseResult (parse ledger "" sample_ledger2)
+  showParseResult (parse ledger "" sample_ledger3)
+  showParseResult (parse ledger "" sample_ledger4)
+  showParseResult (parse ledger "" sample_ledger5)
+  showParseResult (parse ledger "" sample_periodic_entry)
+  showParseResult (parse ledger "" sample_periodic_entry2)
+  parseMyLedgerFile >>= showParseResult 
+    where
+      showParseResult r =
+          case r of
+            Left err -> do putStr "ledger parse error at "; print err
+            Right x  -> print x
+
+      
+
+--   assert_ $ amount t1 == 8.50
+--   putStrLn "ok"
+--     where assert_ e = assert e return ()