I show how this can be done using uu-parsinglib. Note that we have sevral parsers, each having its own type: module Transactions where import Text.ParserCombinators.UU import Text.ParserCombinators.UU.Examples import Data.Char pTagged tag (pAttr, pPayload) = pToken ("<" ++ tag ++ ">") *> pAttr *> spaces *> pPayload <* spaces <* pToken ("") pTag tag pPayload = pToken ("<" ++ tag ++ ">") *> pPayload data OFX = OFX Response deriving Show data Response = Response [Transaction] deriving Show data Transaction = Transaction String String Amount deriving Show data Amount = Amount Int Int deriving Show pAmount = "TRNAMT" `pTag` (Amount <$> pNatural <* pSym '.' <*> pNatural) pTransaction = "STMTTRN" `pTagged` (pAttr, Transaction <$> "TRNUID" `pTag` pLine <*> "NAME" `pTag` pLine <*> pAmount ) pResponse = "STMTRS" `pTagged` (pAttr, Response <$> pList (pTransaction <* spaces)) pOFX = "OFX" `pTagged` (pAttr, OFX <$> pResponse ) pAttr :: Parser String pAttr = pToken "[...]" spaces = pMunch (`elem` " \n\t") pDigitAsInt = digit2Int <$> pDigit pNatural = foldl (\a b -> a * 10 + b ) 0 <$> pList1 pDigitAsInt digit2Int a = ord a - ord '0' pDigit :: Parser Char pDigit = pSym ('0', '9') pLine = pMunch (/='\n') <* spaces main = do input <- readFile "TrInput" run (pOFX <* spaces) input Running the main function on your code gives: *Transactions> :r [1 of 1] Compiling Transactions ( Transactions.hs, interpreted ) Ok, modules loaded: Transactions. *Transactions> main -- -- > Result: OFX (Response [Transaction "9223ry29r389" "THE GROCERY STORE BLABLABLA" (Amount 234 99),Transaction "1237tg832t" "SOME DUDE ON PAYPAL 4781487" (Amount 2174 27)]) -- *Transactions> It is interesting to what happens if your input is incorrect, Doaitse On 10 sep 2010, at 18:53, Jared Jennings wrote:
<OFX>[...] <STMTRS>[...] <STMTTRN>[...] <TRNUID>9223ry29r389 <NAME>THE GROCERY STORE BLABLABLA <TRNAMT>234.99 </STMTTRN> <STMTTRN>[...] <TRNUID>1237tg832t <NAME>SOME DUDE ON PAYPAL 4781487 <TRNAMT>2174.27 </STMTTRN> </STMTRS> </OFX>