cheap_strings_2.rb

module CheapStrings
  def `(str)
    str
  end
end

module A
  extend CheapStrings

  def self.make_lots_of_strings
    10_000_000.times do
      "hello world"
    end
  end

  def self.make_lots_of_cheap_strings
    10_000_000.times do
      `hello world`
    end
  end

  HELLO_WORLD = "hello world".freeze

  def self.make_lots_of_cheap_strings_the_traditional_way
    10_000_000.times do
      HELLO_WORLD
    end
  end
end

require "benchmark"

Benchmark.bmbm do |b|
  b.report "strings" do
    A.make_lots_of_strings
  end

  b.report "cheap strings" do
    A.make_lots_of_cheap_strings
  end

  b.report "traditional cheap strings" do
    A.make_lots_of_cheap_strings_the_traditional_way
  end
end

# Rehearsal -------------------------------------------------------------
# strings                     2.410000   0.000000   2.410000 (  2.413642)
# cheap strings               1.350000   0.000000   1.350000 (  1.345134)
# traditional cheap strings   0.970000   0.000000   0.970000 (  0.968080)
# ---------------------------------------------------- total: 4.730000sec
#
#                                 user     system      total        real
# strings                     2.370000   0.010000   2.380000 (  2.375827)
# cheap strings               1.340000   0.000000   1.340000 (  1.338522)
# traditional cheap strings   0.970000   0.000000   0.970000 (  0.968473)