Comparing ruby's `define_method` to each type of `eval` for defining methods

compare_define_method_with_eval.rb

# requires installing "benchmark-ips" (`$ gem install benchmark-ips`)
# 
# Sample result
#
#   $ ruby compare_define_method_with_eval.rb
#   Warming up --------------------------------------
#    using_define_method    17.203k i/100ms
#             using_eval    29.526k i/100ms
#      using_module_eval    30.355k i/100ms
#       using_class_eval    30.809k i/100ms
#   Calculating -------------------------------------
#    using_define_method    182.710k (± 2.8%) i/s -    928.962k in   5.088524s
#             using_eval    334.404k (± 3.3%) i/s -      1.683M in   5.038579s
#      using_module_eval    334.300k (± 4.7%) i/s -      1.670M in   5.005709s
#       using_class_eval    343.665k (± 3.8%) i/s -      1.725M in   5.027972s
#
#   Comparison:
#       using_class_eval:   343664.7 i/s
#             using_eval:   334403.9 i/s - same-ish: difference falls within error
#      using_module_eval:   334299.7 i/s - same-ish: difference falls within error
#    using_define_method:   182710.2 i/s - 1.88x  slower
#

class BasePlayer
  METHODS_TYPES = %w[move look kick punch].freeze
  METHODS_MODS  = {
    :up        => { :x => 0,  :y => 1,  :z => 0  }.freeze,
    :down      => { :x => 0,  :y => -1, :z => 0  }.freeze,
    :left      => { :x => -1, :y => 0,  :z => 0  }.freeze,
    :right     => { :x => 1,  :y => 0,  :z => 0  }.freeze,
    :straight  => { :x => 0,  :y => 0,  :z => 1  }.freeze,
    :backwards => { :x => 0,  :y => 0,  :z => -1 }.freeze
  }.freeze

  def initialize
    @x = 0
    @y = 0
    @z = 0
  end

  # Used to basically confirm that all of the implementations are doing the
  # same thing when executing `#perform_all`
  def perform_and_compare amount=1
    perform_all amount
    raise "something isn't right..." unless @x == 0 && @y == 0 && @z == 0
  end

  # not metaprogrammed to be consistent between the two tests... if that matters...
  def perform_all amount
    move_up amount
    move_down amount
    move_left amount
    move_right amount
    move_straight amount
    move_backwards amount
    look_up amount
    look_down amount
    look_left amount
    look_right amount
    look_straight amount
    look_backwards amount
    kick_up amount
    kick_down amount
    kick_left amount
    kick_right amount
    kick_straight amount
    kick_backwards amount
    punch_up amount
    punch_down amount
    punch_left amount
    punch_right amount
    punch_straight amount
    punch_backwards amount
  end
end

class UsingDefineMethod < BasePlayer
  METHODS_TYPES.each do |type|
    METHODS_MODS.keys.each do |dir|
      define_method "#{type}_#{dir}" do |amount=1|
        @x += METHODS_MODS[dir][:x] * amount
        @y += METHODS_MODS[dir][:y] * amount
        @z += METHODS_MODS[dir][:z] * amount
      end
    end
  end
end

class UsingEval < BasePlayer
  METHODS_TYPES.each do |type|
    METHODS_MODS.keys.each do |dir|
      eval <<-CODE
        def #{type}_#{dir} amount=1
          @x += #{METHODS_MODS[dir][:x]} * amount
          @y += #{METHODS_MODS[dir][:y]} * amount
          @z += #{METHODS_MODS[dir][:z]} * amount
        end
      CODE
    end
  end
end

class UsingModuleEval < BasePlayer
  METHODS_TYPES.each do |type|
    METHODS_MODS.keys.each do |dir|
      module_eval <<-CODE
        def #{type}_#{dir} amount=1
          @x += #{METHODS_MODS[dir][:x]} * amount
          @y += #{METHODS_MODS[dir][:y]} * amount
          @z += #{METHODS_MODS[dir][:z]} * amount
        end
      CODE
    end
  end
end

class UsingClassEval < BasePlayer
  METHODS_TYPES.each do |type|
    METHODS_MODS.keys.each do |dir|
      class_eval <<-CODE
        def #{type}_#{dir} amount=1
          @x += #{METHODS_MODS[dir][:x]} * amount
          @y += #{METHODS_MODS[dir][:y]} * amount
          @z += #{METHODS_MODS[dir][:z]} * amount
        end
      CODE
    end
  end
end


require 'benchmark/ips'

using_define_method = UsingDefineMethod.new
using_eval          = UsingEval.new
using_module_eval   = UsingModuleEval.new
using_class_eval    = UsingClassEval.new

Benchmark.ips do |bench|
  bench.report("using_define_method") { using_define_method.perform_and_compare 5 }
  bench.report("using_eval")          { using_eval.perform_and_compare 5 }
  bench.report("using_module_eval")   { using_module_eval.perform_and_compare 5 }
  bench.report("using_class_eval")    { using_class_eval.perform_and_compare 5 }

  bench.compare!
end