Binary IO

Data.Binary

There are a number of binary I/O libraries available for Haskell. The best to use is the new, semi-standard Data.Binary library:

   * Data.Binary

It's very simple to use, and provides a highly efficient, pure interface to binary serialisation.

For just writing binary data to file, use

   * System.IO

It is a part of the base package, so it comes with GHC.

A tutorial:

   * Serialisation and compression with Data Binary

See also Dealing with binary data

Other libraries

• JeremyShaw's update of HalDaume's NewBinary package (Cabalized): http://www.n-heptane.com/nhlab/repos/NewBinary
• Data.ByteString (Cabalised) also provides byte level operations, and is used in some applications for binary IO
• SerTH, the TH version (sort of) of NewBinary.
• PeterSimons's BlockIO package (Cabalized): http://cryp.to/blockio/
• JohnGoerzen's MissingH package (Cabalized): http://quux.org/devel/missingh
• SimonMarlow's experimental NewIO package: http://www.haskell.org/~simonmar/new-io.tar.gz (documentation at http://www.haskell.org/~simonmar/io/)

For very simple serialisation, use read and show.

If you have simple binary IO requirements, then Data.ByteString might be easiest -- you get a List-like interface to packed byte arrays (interface documented here). For more complex serialisation, Data.Binary would be preferred.