This is Hoopl, a higher-order optimization library.
There are two unpublished papers describing Hoopl:

  Hoopl: Dataflow Optimization Made Simple
  Hoopl: A Modular, Reusable Library for Dataflow Analysis and Transformation

The second such paper is attached to this package.

The version number is split into four parts:

  3.   Third major body plan (phylum)
  7.   Seventh iteration (roughly) of data structures
  2.   Major version; changes when clients must change
  1.   Minor version; changes when clients can stay the same


Version 3.7.3.3 has fixed known bugs.

Version 3.7.8.0 will be the last version uploaded to Hackage for some time.
This library is undergoing *very* rapid development, and we ask that you
get the most recent version from our public git repository:

  git clone -o tufts git://ghc.cs.tufts.edu/hoopl/hoopl.git

If you are not familiar with git, we recommend the tutorial 'Git Magic'
by Ben Lynn.