redisarray.rb

require 'redis'

class Set 

  def initialize(*elems)
    if !defined? @@redis
      @@redis = Redis.new
    end 
    elems.each do |elem|
      @@redis.set_add(object_id, elem)
    end 
  end 

  def members
    @@redis.set_members(object_id)
  end 

  def union(other)
    ret = Set.new
    @@redis.set_union_store(ret.object_id, object_id, other.object_id)
    ret 
  end 
end

a = Set.new(1,2)
b = Set.new(3,4)
puts a.union(b).members #1,2,3,4