
High priority (before next release)
=============
* Improve the Perl regular expressions parser
* Character classes (in the three regular expression parsers)

* Reduce memory usage
  - More compact representation of character sequences
  - Special notation for "anything but this set of characters"
  (more generally, optimize the compilation of regular expressions)
* Simple optimisations
  - alt containing alt
  - epsilon elimination
  - Seq (Seq (x,y), z) => Seq (x, Seq (y, z)) under some circumptances
    (x or y has a fixed length)
  ...

* Test suite

Medium priority
===============
* Implement back-references
* Implement look-ahead and look-behind assertions

Low priority
============
* Optimize the main loop for processor that are not register starved
* Rewrite the main loops in C
  (but keep the option to compile a pure OCaml version)
* Limit the size of the cached DFAs by removing states that have not
  been used recently
* Documentation

Other ideas
===========
* It would be great to have a more generic interface (parameterized
  over some abstract tokens).
* Str compatibility module
  (should we implement string_partial_match?)
