Parser

ASnapshot.hs

{-# LANGUAGE BangPatterns #-}

import Data.Attoparsec.Text
import Control.Applicative ((*>),(<*))
import qualified Data.Text.IO as TL
import Data.Text

newtype VehicleId = VehicleId Int deriving Show
newtype Time = Time Int deriving Show
newtype LinkID = LinkID Int deriving Show
newtype NodeID = NodeID Int deriving Show
newtype LaneID = LaneID Int deriving Show

tab :: Parser Char
tab = char '\t'

data Snapshot = Snapshot {
  vehicle :: !VehicleId,
  time :: !Time,
  link :: !LinkID,
  node :: !NodeID,
  lane :: !LaneID,
  distance :: !Double,
  velocity :: !Double,
  vehtype :: !Int,
  acceler :: !Double,
  driver :: !Int,
  passengers :: !Int,
  easting :: !Double,
  northing :: !Double,
  elevation :: !Double,
  azimuth :: !Double,
  user :: !Int
  } deriving (Show)

snapshotParser :: Parser Snapshot
snapshotParser = do
  !sveh <- decimal
  tab
  !stime <- decimal
  tab
  !slink <- decimal
  tab
  !snode <- decimal
  tab
  !slane <- decimal
  tab
  !sdistance <- double
  tab
  !svelocity <- double
  tab
  !svehtype <- decimal
  tab
  !sacceler <- double
  tab
  !sdriver <- decimal
  tab
  !spassengers <- decimal
  tab
  !seasting <- double
  tab
  !snorthing <- double
  tab
  !selevation <- double
  tab
  !sazimuth <- double
  tab
  !suser <- decimal
  endOfLine
  return $ Snapshot (VehicleId sveh) (Time stime) (LinkID slink) (NodeID snode) (LaneID slane) sdistance svelocity svehtype sacceler sdriver spassengers seasting snorthing selevation sazimuth suser

doStuff :: Text -> [Snapshot] -> IO ()
doStuff text acc = case parse snapshotParser text of
  Done !i !r -> doStuff i (r:acc)
  Partial _ -> print "done stuff"
  Fail i d msg-> print i

main :: IO ()
main = do
  text <- TL.readFile "./Snapshot"
  doStuff text []