benchmark-inline.rb

require 'benchmark'
require './integer'
require 'prime'

Benchmark.bmbm do |bench|
  bench.report 'simple:' do
    (2..100_000).each { |i| i.simple_prime? }
  end
  bench.report 'clever:' do
    (2..100_000).each { |i| i.clever_prime? }
  end
  bench.report 'stdlib:' do
    (2..100_000).each { |i| i.prime? }
  end
  bench.report 'inline:' do
    (2..100_000).each { |i| i.inline_clever }
  end
end

benchmark-stdlib.rb

require 'benchmark'
require './integer'
require 'prime'

Benchmark.bmbm do |bench|
  bench.report 'simple:' do
    (2..100_000).each { |i| i.simple_prime? }
  end
  bench.report 'clever:' do
    (2..100_000).each { |i| i.clever_prime? }
  end
  bench.report 'stdlib:' do
    (2..100_000).each { |i| i.prime? }
  end
end

benchmark.rb

require 'benchmark'
require './integer'
require 'prime'

Benchmark.bmbm do |bench|
  bench.report 'stupid:' do
    (2..10_000).each { |i| i.stupid_prime? }
  end
  bench.report 'tedious:' do
    (2..10_000).each { |i| i.tedious_prime? }
  end
  bench.report 'simple:' do
    (2..10_000).each { |i| i.simple_prime? }
  end
  bench.report 'clever:' do
    (2..10_000).each { |i| i.clever_prime? }
  end
  bench.report 'stdlib:' do
    (2..10_000).each { |i| i.prime? }
  end
end

euler.rb

require './integer'
require 'prime'

limit  = ARGV.first.to_i
method = ARGV.last.to_sym

sum = (2...limit).select(&method).inject :+

puts "sum(primes < #{limit}) = #{sum}"

gems.sh

#!/bin/sh

gem install ruby_core_source ruby-prof perftools.rb RubyInline

integer.rb

require 'inline'

class Integer

  def stupid_prime?
    prime = true
    (2...self).each { |i| prime = false if (self % i).zero? }
    prime
  end

  def tedious_prime?
    (2...self).all? { |i| (self % i).nonzero? }
  end

  def simple_prime?
    (2..Math.sqrt(self).floor).all? { |i| (self % i).nonzero? }
  end

  def clever_prime?
    return true  if self == 2
    return false if self.even?
    3.step(Math.sqrt(self).floor, 2).all? { |i| (self % i).nonzero? }
  end

  inline do |builder|
    builder.c '
      VALUE inline_simple() {
        long number = NUM2LONG(self);
        long i;
        for (i = 2; i <= floor(sqrt(number)); i++) {
          if (number % i == 0) return Qfalse;
        }
        return Qtrue;
      }
    '
  end

  inline do |builder|
    builder.c '
      VALUE inline_clever() {
        long number = NUM2LONG(self);
        if (number == 2)     return Qtrue;
        if (number % 2 == 0) return Qfalse;
        long i = 3;
        while (i <= floor(sqrt(number))) {
          if (number % i == 0) return Qfalse;
          i = i + 2;
        }
        return Qtrue;
      }
    '
  end

end

take_while.rb

require 'prime'

puts Prime.take_while { |p| p < 2_000_000 }.inject :+