cache_stats             Report cache statistics.
hashmap                 A reference-valued, key-value store.
memo                    Memoize a function.
memo-package            In-memory caching of repeated computations, by
                        pointer equivalence.
permanent_cache         'permanent_cache' constructs a cache that does
                        not expire old entries. It should be used in
                        situations where you know the number of values
                        to remember is bounded.
strategies              Strategies for caching items.
