A simple Haskell library that implements Tarjan's Union/Find algorithm. Useful, for example, to implement unification in a type inference system.
The Union/Find algorithm implements these operations in (effectively) constant-time:
Check whether two elements are in the same equivalence class.
Create a union of two equivalence classes.
Look up the descriptor of the equivalence class.
cabal (which comes with the Haskell Platform):
$ cabal install union-find
or in the checked-out repository:
$ cabal install