Generic Programming
Regular

GenericProgramming
---++ Introduction

Many generic programs require information about the recursive positions
of a datatype. Examples include the generic fold, generic rewriting, and
the Zipper data structure. This approach provides a fixed point view on
data which allows these definitions for regular datatypes. It can be seen
as a simplification of the [[http://hackage.haskell.org/package/multirec][Multirec library]],
which provides similar functionality but for families of (possibly mutually recursive) datatypes.

This library is the underlying generic representation mechanism in the paper:
  Thomas van Noort, Alexey Rodriguez, Stefan Holdermans, Johan Jeuring, 
  Bastiaan Heeren. [[http://www.cs.uu.nl/wiki/bin/view/Alexey/ALightweightApproachToDatatype-GenericRewriting][A Lightweight Approach to Datatype-Generic Rewriting.]]
  In Ralf Hinze and Don Syme, editors, Proceedings of the ACM SIGPLAN Workshop 
  on Generic Programming, WGP 2008, Victoria, BC, Canada, September 20, 2008, 
  pages 13&#8211;24. ACM Press, 2008.

Together with the core library and generic functions, we also provide an extra package, regular-extras, with additional functionality (dependent on other packages). Currently these extra functions are:
   * [[http://hackage.haskell.org/package/QuickCheck-1.2.0.0][QuickCheck]]'s arbitrary, with an option to provide size, and frequencies for each constructor;
   * [[http://hackage.haskell.org/package/QuickCheck-1.2.0.0][QuickCheck]]'s coarbitrary;
   * [[http://hackage.haskell.org/package/binary-0.5.0.2][Data.Binary]] get and put.

---++ Download

_If you have [[http://hackage.haskell.org/package/cabal-install][cabal-install]]_, you should use that to install the package,
because it will handle everything for you:

<pre>
cabal install regular
</pre>

or

<pre>
cabal install regular-extras
</pre>

_If you don't have cabal-install_, you must download the [[http://hackage.haskell.org/package/regular][regular package]] and the [[http://hackage.haskell.org/package/regular-extras][regular-extras package]] from !HackageDB and install them manually. Get the =tar.gz= files and decompress them.

Once downloaded, use the following commands for configuring, building, and installing the library:

<pre>
runghc Setup configure
runghc Setup build
runghc Setup install
</pre>

For more details on the general options available, refer to the [[http://www.haskell.org/cabal/release/latest/doc/users-guide/][Cabal User's Guide]].

---++ Source

The source for this library can be downloaded from the [[http://subversion.tigris.org/][Subversion]] repository as follows:

<pre>
svn checkout <a href="https://subversion.cs.uu.nl/repos/project.dgp-haskell.libraries/regular/trunk/">https://subversion.cs.uu.nl/repos/project.dgp-haskell.libraries/regular/trunk/</a>
</pre>