Arrows: A General Interface to Computation

arrowp
A preprocessor for arrows notation, implemented by Ross Paterson.

Note: GHC 6.2 or later has built-in support for arrow notation, so if you're only using GHC, you don't need this preprocessor: just rename your arrow module as an ordinary Haskell source file and invoke GHC with the -XArrows option. You'll get better error messages for arrow code, too.

The development version can be obtained with

    darcs get http://code.haskell.org/~ross/arrowp
Control.Arrow
A module containing the definitions from [Hug00], plus the ArrowLoop class from [Pat01]. It is included in the Haskell hierarchical libraries; if you have a fairly recent release of GHC, Hugs or NHC, you already have this module.
arrows
An experimental library of arrow classes and transformers, defining various operations supported by different arrow types, and arrow transformers that supply or lift instances of these classes:

The development version can be obtained with

    darcs get http://code.haskell.org/~ross/arrows

Ross Paterson