Ruby 2.0 lazy enumerators small collection performance

enum_perf_small.rb

require "benchmark"
include Benchmark

values = (0..10_000_000).to_a

bm(1_000_000) do |bench|
   bench.report("map and select") do
      values.map { |x| x * 3 }.select { |x| x % 4 == 0 } 
   end
   bench.report("inject") do
      values.inject([]) do |arr, x|
         y = x * 3
         arr << y if y % 4 == 0
         arr
      end
   end
   bench.report("each with object") do
      values.each_with_object([]) do |x, arr|
         y = x * 3
         arr << y if y % 4 == 0
      end
   end
end

include Benchmark

values = (0..10000).to_a

bm(100) do |bench|
  bench.report("inject") do
      values.reduce([]) do |arr, x|
         y = x * 10
         arr << y if x % 2 == 0
         arr
      end
   end
   bench.report("map and select") do
      values.map { |x| x * 10 }.select { |x| x % 2 == 0 } 
   end
end