examples/attoparser.hs

   1 import Pipes
   2 import Pipes.Text.IO (fromHandle)
   3 import Pipes.Attoparsec (parsed)
   4 import qualified System.IO as IO
   5 import Data.Attoparsec.Text
   6 import Control.Applicative
   7 data Test = Test {
   8   a :: Int,
   9   b :: Int
  10   } deriving (Show)
  11
  12 testParser :: Parser Test
  13 testParser = do
  14   a <- decimal
  15   space
  16   b <- decimal
  17   endOfLine
  18   return $ Test a b
  19
  20 main = IO.withFile "./testfile" IO.ReadMode $ \handle -> runEffect $
  21    do leftover <- for (parsed testParser (fromHandle handle))
  22                    (lift . print)
  23       return () -- ignore unparsed material
  24
  25 -- >>> :! cat testfile
  26 -- 1 1
  27 -- 2 2
  28 -- 3 3
  29 -- 4 4
  30 -- 5 5
  31 -- 6 6
  32 -- 7 7
  33 -- 8 8
  34 -- 9 9
  35 -- 10 10
  36
  37 -- >>> main
  38 -- Test {a = 1, b = 1}
  39 -- Test {a = 2, b = 2}
  40 -- Test {a = 3, b = 3}
  41 -- Test {a = 4, b = 4}
  42 -- Test {a = 5, b = 5}
  43 -- Test {a = 6, b = 6}
  44 -- Test {a = 7, b = 7}
  45 -- Test {a = 8, b = 8}
  46 -- Test {a = 9, b = 9}
  47 -- Test {a = 10, b = 10}
  48
  49