This module contains Get and Put method implementations for ISO 8583 style bitmaps, and also utility methods for getting/putting fields in formats commonly used in ISO 8583 specification.

Typical usage is:

data Message = Message {pan :: B.ByteString, stan :: Integer}
deriving (Eq, Show)

data FieldValue = String B.ByteString | Int Integer
deriving (Eq, Show)

getField :: Int -> Maybe (Get FieldValue)
getField 2 = Just $ String `fmap` embeddedLen 2
getField 11 = Just $ Int `fmap` asciiNumberF 11 6
getField _ = Nothing

getMessage :: Get Message
getMessage = do
  m <- getBitmap getField
  let Just (String pan) = M.lookup 2 m
  let Just (Int stan) = M.lookup 11 m
  return $ Message pan stan

putMessage :: Message -> Put
putMessage (Message pan stan) = do
  putBitmap [(2, putEmbeddedLen 2 pan),
             (11, putAsciiNumber 6 stan)]