redisarray.rb

require 'redis'

class Set

  def initialize(*elems)
    @redis = Redis.new
    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