ghc-io-streams
Simple, composable, and easy-to-use stream I/O
/Overview/ The io-streams library contains simple and easy-to-use primitives for I/O using streams. Most users will want to import the top-level convenience module "System.IO.Streams", which re-exports most of the library: ' import System.IO.Streams (InputStream, OutputStream) import qualified System.IO.Streams as Streams ' For first-time users, 'io-streams' comes with an included tutorial, which can be found in the "System.IO.Streams.Tutorial" module. /Features/ The 'io-streams' user API has two basic types: 'InputStream a' and 'OutputStream a', and three fundamental I/O primitives: ' -- read an item from an input stream Streams.read :: InputStream a ->IO (Maybe a) -- push an item back to an input stream Streams.unRead :: a ->InputStream a ->IO () -- write to an output stream Streams.write :: Maybe a ->OutputStream a ->IO () ' Streams can be transformed by composition and hooked together with provided combinators: ' ghci>Streams.fromList [1,2,3::Int]>>= Streams.map (*10)>>= Streams.toList [10,20,30] ' Stream composition leaves the original stream accessible: ' ghci>input<- Streams.fromByteString "long string" ghci>wrapped<- Streams.takeBytes 4 input ghci>Streams.read wrapped Just "long" ghci>Streams.read wrapped Nothing ghci>Streams.read input Just " string" ' Simple types and operations in the IO monad mean straightforward and simple exception handling and resource cleanup using Haskell standard library facilities like 'Control.Exception.bracket'. 'io-streams' comes with: * functions to use files, handles, concurrent channels, sockets, lists, vectors, and more as streams. * a variety of combinators for wrapping and transforming streams, including compression and decompression using zlib, controlling precisely how many bytes are read from or written to a stream, buffering output using bytestring builders, folds, maps, filters, zips, etc. * support for parsing from streams using 'attoparsec'. * support for spawning processes and communicating with them using streams.
BSD-3-Clause