Support for the Ruby 2.4 series has ended. See here for reference.
Generates all integers which are greater than 2 and are not divisible by either 2 or 3.
This is a pseudo-prime generator, suitable on checking primality of an integer by brute force method.
 
               # File prime.rb, line 355
def succ
  if (@step)
    @prime += @step
    @step = 6 - @step
  else
    case @prime
    when 1; @prime = 2
    when 2; @prime = 3
    when 3; @prime = 5; @step = 2
    end
  end
  @prime
end