Thursday, May 5, 2011

New release of unordered-containers

I've just uploaded a new version of the unordered-containers package, a package of fast hashing-based container types. Version adds:

  • the ability to take the union of two maps,
  • lower memory overhead per key/value pair (contributed by Jan-Willem Maessen), and
  • the beginning of a Data.HashSet module (contributed by Bryan O'Sullivan).

If you want to contribute, you can get the source from the git repository:

git clone

Alternatively, just fork the project on GitHub.


  1. How much more memory on average does `Data.HashSet` consume per entry compared to `Data.IntSet`?

  2. Anonymous,

    2 words more at the moment. It could be brought down to one quite easily.