Comparing 42.prime? to Prime.prime?(42) for Ruby IRC

integer_prime.rb

class Integer
  def prime?
    return self >= 2 if self <= 3


    if (bases = miller_rabin_bases)
      return miller_rabin_test(bases)
    end


    return true if self == 5
    return false unless 30.gcd(self) == 1
    (7..Integer.sqrt(self)).step(30) do |p|
      return false if
        self%(p)    == 0 || self%(p+4)  == 0 || self%(p+6)  == 0 || self%(p+10) == 0 ||
        self%(p+12) == 0 || self%(p+16) == 0 || self%(p+22) == 0 || self%(p+24) == 0
    end
    true
  end
end

prime_prime.rb

class Prime
  class << self
    def prime?(value, generator = Prime::Generator23.new)
      raise ArgumentError, "Expected a prime generator, got #{generator}" unless generator.respond_to? :each
      raise ArgumentError, "Expected an integer, got #{value}" unless value.respond_to?(:integer?) && value.integer?
      return false if value < 2
      generator.each do |num|
        q,r = value.divmod num
        return true if q < num
        return false if r == 0
      end
    end
  end
end