ruby memoization benchmarks

memo.rb

require "benchmark"

class A
  def name
    @name ||= begin
      rand
    end
  end
end

class B
  def name
    return(@name) if defined?(@name)
    @name = rand
  end
end

class C
  def name
    def self.name
      @name
    end
    @name = rand
  end
end

class D
  def name
    class << self
      def name
        @name
      end
    end
    @name = rand
  end
end

class Z
  def name
    @name ||= rand
  end
end

m = 1_000
n = 100_000
Benchmark.bm(2) do |x|
  x.report("A:") { m.times { k = A.new; n.times { k.name } } }
  x.report("B:") { m.times { k = B.new; n.times { k.name } } }
  x.report("C:") { m.times { k = C.new; n.times { k.name } } }
  x.report("D:") { m.times { k = D.new; n.times { k.name } } }
  x.report("Z:") { m.times { k = Z.new; n.times { k.name } } }
end