Enumerator#lazy benchmarking

lazy.rb

# Enumerator#lazy is very slow and should only be used when iterating over large/infinite collections
# where you know you are going to get your results quite early in the iteration.

# This benchmark is purposely made to advantage the lazy version, without much success.

require 'benchmark/ips'

class Enumerator::Lazy
  def filter_map
    Lazy.new(self) do |yielder, *values|
      result = yield *values
      yielder << result if result
    end
  end
end

Benchmark.ips do |r|  
  r.report("map+compact") do
    (0..50).map{|a| 'lol' if a.even?}.compact.first(5)
  end

  r.report("filter_map") do
    (0..50).lazy.filter_map{|a| 'lol' if a.even?}.first(5)
  end
end

Calculating -------------------------------------
         map+compact     12035 i/100ms
          filter_map     10588 i/100ms
-------------------------------------------------
         map+compact   135411.8 (±0.9%) i/s -     685995 in   5.066383s
          filter_map   114386.4 (±4.9%) i/s -     571752 in   5.010041s