Subject: ANN: fclabels-0.4.0 - First class accessor labels.
Date: Friday 4th September 2009 10:56:25 UTC (over 7 years ago)
Hello all, IFCP is a really inspiring place to hang/hack around with your fellow Haskell hackers. So, straight from Edinburgh, I proudly present a new release of fclabels[1,2], your favourite record selector package. This version is joint work with Chris Eidhof and Sjoerd Visscher. This package has been around for a while but has been changed almost entirely now. Naming is different and has a far more consistent usage. This library might look cryptic at first sight, but give it a try it is not that hard. There are more package around that serve the same purpose (like the Lenses package which was uploaded a few days ago), but I'm convinced the simplicity and elegance of fclabels will strike you all. ;-) The package description is included below. Documentation can be found in the package itself or on Hackage. Gr, -- Sebastiaan Visser  Hackage: http://hackage.haskell.org/package/fclabels  Github: http://github.com/sebastiaanvisser/fclabels/tree/master * package description * First class labels that act as bidirectional records fields. The labels are fully composable and can be used to get, set and modify part of datatypes in a consistent way. The label datatype, conveniently called `:->', is an instance of the `Category' type class meaning it has a proper identity and composition. The library has support for automatically deriving labels from record selectors that start with an underscore. Labels can be used in a pure functional setting or be applied to mutable state in some state monad.