simple-pipe: simple pipeline library like conduit

examples/upperFile.hs

• read file (sample.txt)

• take 3 lines

• to upper all lines

• write to stdout

extensions

• PackageImports

 import Data.Pipe
 import Data.Char
 import System.IO
 import "monads-tf" Control.Monad.Trans

 main :: IO ()
 main = do
 	_ <- runPipe $ readFileP "sample.txt"
		=$= takeP 3
		=$= convert (map toUpper)
		=$= writeString
 	return ()

 readFileP :: FilePath -> Pipe () String IO ()
 readFileP fp = bracket (openFile fp ReadMode) hClose hRead

 hRead :: Handle -> Pipe () String IO ()
 hRead h = do
 	eof <- lift $ hIsEOF h
 	if eof then return () else do
 		l <- lift $ hGetLine h
 		yield l
 		hRead h

 writeString :: Pipe String () IO ()
 writeString = do
 	ms <- await
 	case ms of
 		Just s -> lift (putStrLn s) >> writeString
 		_ -> return ()

 takeP :: Monad m => Int -> Pipe a a m ()
 takeP 0 = return ()
 takeP n = do
	mx <- await
	case mx of
		Just x -> yield x >> takeP (n - 1)
		_ -> return ()

Modules

[Index]

Downloads

• simple-pipe-0.0.0.29.tar.gz [browse] (Cabal source package)
• Package description (revised from the package)

Note: This package has metadata revisions in the cabal description newer than included in the tarball. To unpack the package including the revisions, use 'cabal get'.

Maintainer's Corner

For package maintainers and hackage trustees

• edit package information

Candidates

• No Candidates