BSD-3-Clause licensed by Johan Tibell
Maintained by [email protected]
This version can be pinned in stack with:unordered-containers-,4169

Module documentation for

Efficient hashing-based container types. The containers have been optimized for performance critical use, both in terms of large data quantities and high speed.

The declared cost of each operation is either worst-case or amortized, but remains valid even if structures are shared.


  • Fix linker error related to popcnt.

  • Haddock improvements.

  • Fix benchmark compilation when downloaded from Hackage.

  • Support criterion 1.1

  • Add unionWithKey for hash maps.

  • Mark several modules as Trustworthy.

  • Add Hashable instances for HashMap and HashSet.

  • Add mapMaybe, mapMaybeWithKey, update, alter, and intersectionWithKey.

  • Add roles.

  • Add Hashable and Semigroup instances. (2014-10-11)

  • Support base-4.8