Multimap¶ ↑

A Ruby multimap implementation that also includes multiset and nested multimap implementations.

require 'multimap'

map = Multimap.new
map["a"] = 100
map["b"] = 200
map["a"] = 300

map["a"]                              # -> [100, 300]
map["b"]                              # -> [200]
map.keys                              # -> #<Multiset: {"a", "a", "b"}>