  The package hset for the R language contains an implementation of a S4 class
for sets and multisets of numbers. The implementation, based on the hash table
data structure from the package hash (Brown, 2019), allows for quick operations
when the set is a dynamic object. An important example is when a set or a
multiset is part of the state of a Markov chain in which in each iteration
various elements are moved in and out of the set.
