io-streams-1.3.6.0: 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 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.
Modules
- System
- IO
- System.IO.Streams
- System.IO.Streams.Attoparsec
- System.IO.Streams.Builder
- System.IO.Streams.ByteString
- System.IO.Streams.Combinators
- System.IO.Streams.Concurrent
- System.IO.Streams.Core
- System.IO.Streams.Debug
- System.IO.Streams.File
- System.IO.Streams.Handle
- System.IO.Streams.Internal
- System.IO.Streams.List
- System.IO.Streams.Network
- System.IO.Streams.Process
- System.IO.Streams.Text
- System.IO.Streams.Tutorial
- System.IO.Streams.Vector
- System.IO.Streams.Zlib
- System.IO.Streams
- IO