micro-benchmark comparing various ways to capture and forward a block

yield-vs-block.rb

#!/usr/bin/env ruby
require 'benchmark'
require 'forwardable'

puts RUBY_DESCRIPTION

class TestMe
  extend Forwardable
  def_delegators :@arr, :each

  def initialize arr
    @arr = arr
  end

  def each_block_forward &b
    @arr.each(&b)
  end

  def each_block_call &b
    @arr.each {|e| b.call(e) }
  end

  def each_yield
    @arr.each { |e| yield e }
  end
end

N = 500_000
M = 100

a = (0...M).to_a
t = TestMe.new a

Benchmark.bmbm do |x|
  x.report('nop')              { N.times { } }
  x.report('raw')              { N.times { a.each       {|e| e } } }
  x.report('block_forward')    { N.times { t.each_block_forward {|e| e } } }
  x.report('block_call')       { N.times { t.each_block_call {|e| e } } }
  x.report('yield')            { N.times { t.each_yield {|e| e } } }
  x.report('delegate')         { N.times { t.each       {|e| e } } }
end

__END__

$ ./yield-vs-block.rb
ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-darwin13]
Rehearsal -------------------------------------------------
nop             0.020000   0.000000   0.020000 (  0.019612)
raw             2.490000   0.000000   2.490000 (  2.500898)
block_forward   2.700000   0.010000   2.710000 (  2.718873)
block_call      6.930000   0.010000   6.940000 (  6.953126)
yield           3.700000   0.000000   3.700000 (  3.709342)
delegate        2.690000   0.000000   2.690000 (  2.696791)
--------------------------------------- total: 18.550000sec

                    user     system      total        real
nop             0.020000   0.000000   0.020000 (  0.020016)
raw             2.280000   0.000000   2.280000 (  2.286575)
block_forward   2.610000   0.010000   2.620000 (  2.607132)
block_call      6.400000   0.000000   6.400000 (  6.418502)
yield           3.680000   0.010000   3.690000 (  3.680618)
delegate        2.790000   0.000000   2.790000 (  2.799740)