From: daz <dooby@...10.karoo.co.uk>
Date: 2003-07-09T15:08:41+09:00
Subject: Re: Possible use for a continuation? [Generating all factors of a given number]


"Harry Ohlsen" <harryo@qiqsolutions.com> wrote:

> [...] since in many cases, I'll decide after having
> processed one of them that I don't need any more.
>
> I'm open to any suggestions, whatsoever.
>

Glad you said that ;)

Continuations might be more-than-required since you
suggest that when a condition arises, the game is up.

catch / throw may be what you need.

N.B.  I haven't done the job but just to show that
      throw can be issued from anywhere ...

def gen_value_single(n, r)
  ret_ = []
  0.upto(r) do |i|
    ret_ << n ** i
    throw :enough if ((false))
  end
  ret_
end

def gen_values(arr)
  all_done = false
  catch :enough do
    arr.each do |n, r|
      p gen_value_single(n, r)
      #
      ### accumulate stuff
      #
      throw :enough if ((false))
    end
    all_done = true
  end # post-catch
  return all_done
end

gen_values( [[2,3], [3,2], [5,2], [7,1]] )


And, because I don't know your condition,
I've entered false.

The (useless) output from above is:

[1, 2, 4, 8]
[1, 3, 9]
[1, 5, 25]
[1, 7]



daz