Use callcc for non-recursive factorials.

factorials_in_cc.rb

require 'continuation'

class FactorialsInCC
  def fact(n)
    factorial = 1
    callcc { |fact_jmp| @fact_jmp = fact_jmp }

    factorial *= n
    n -= 1

    @fact_jmp.call if n > 1
    factorial
  end
end

puts FactorialsInCC.new.fact(ARGV[0].to_i)

Been sitting on this a while. Non-recursive using callcc for quick jump back. Obviously you don't need to be recursive to do factorials anyway, but it's a neat alternative to a loop.

@fact_jmp.call = goto

I love goto. It's so efficient.

Cool stuff. Neat way to queue up some logic.

Careful though; Its kinda like setting a trap. Thing is, set enough traps and you will eventually catch yourself in one.

It gets really cool when you start passing the continuations around.

Haha, i'm just busting your balls. It really is cool stuff. Have you done anything useful with it yet?

Hah, not yet. At least not in Ruby. In Ruby, I think callcc is a solution looking for a problem. A good use case may not actually exist.

That's exactly what I said!!

Did not! Er, where?

I told you it was a trap!

On Thu, Jan 26, 2012 at 10:41 PM, Scott Deming < ***@***.*** > wrote: Did not! Er, where? --- Reply to this email directly or view it on GitHub: https://gist.github.com/1680865

## Justin Mazzi