phrug code review 3 bm

#!/usr/bin/env ruby -w
require 'benchmark'

n = 1_000_000
l = (1..n).to_a.shuffle

conditions = [
  proc { |i| i > 5 },
  proc { |i| (i % 2).zero? },
  proc { |i| (i % 3).zero? },
  proc { |i| i**2 - 2*i > i**1.5 }
]

Benchmark.bmbm do |x|
  x.report("select") do
    l.select { |i| i > 5 && (i % 6).zero? && i**2 - 2*i > i**1.5 }.join(', ')
  end
  x.report("select 2") do
    l.select { |i| i > 5 && (i % 2).zero? && (i % 3).zero? && i**2 - 2*i > i**1.5 }.join(', ')
  end
  x.report("select-all?") do
    l.select do |i|
      conditions.all? { |c| c[i] }
    end.join(', ')
  end
  x.report("inject-select") do
    conditions.inject(l) {|a, e| a.select(&e) }.join(", ")
  end
  x.report("inject-inject") do
    conditions.inject(l) {|a, e| a.inject([]) {|acc, el| e[el] ? acc << el : acc }  }.join(", ")
  end
end

__END__

Rehearsal -------------------------------------------------
select          0.800000   0.010000   0.810000 (  0.806892)
select 2        0.860000   0.000000   0.860000 (  0.869066)
select-all?     3.860000   0.010000   3.870000 (  3.859497)
inject-select   1.070000   0.010000   1.080000 (  1.082038)
inject-inject   1.850000   0.020000   1.870000 (  1.876395)
---------------------------------------- total: 8.490000sec

                    user     system      total        real
select          0.860000   0.000000   0.860000 (  0.861155)
select 2        0.930000   0.000000   0.930000 (  0.931503)
select-all?     4.310000   0.000000   4.310000 (  4.309884)
inject-select   1.120000   0.020000   1.140000 (  1.138431)
inject-inject   1.860000   0.020000   1.880000 (  1.883042)