@hackage disjoint-set-stateful0.1.1.0

This package includes a monadic disjoint int set datatype, which can also be "frozen" into a non-monadic queriable disjoint set (which however can not be modified).

In the future, I will write a wrapper that allows disjoint sets for all datatypes.

One common use case for disjoint sets is for creating equivalence classes.