From: Brian Candler <B.Candler@...>
Date: 2003-07-09T18:29:37+09:00
Subject: Re: Possible use for a continuation? [Generating all factors of a given number]

On Wed, Jul 09, 2003 at 05:40:40PM +0900, Harry Ohlsen wrote:
> which can be called like ...
> 
>    isGenerator = true
> 
>    Primes.each_factor(phi) do |factor|
>       exponent = phi / factor
> 
>       if (i ** exponent).to_i == 1
>           isGenerator = false
>       end
> 
>       isGenerator
>    end
> 
> The only problem with this is that you can't really "return" a value from
> a block (or, at least, I don't believe so), which makes the last line,
> which has to "return" true or false, so that the iterator knows whether to
> continue, isn't quite as obvious as I'd like.

IIRC, 1.8 has "next <expr>" and "break <expr>" which return a value.

In the above case, if 'isGenerator = false' terminates the loop, you could
just write

     exponent = phi / factor
     (i ** exponent).to_i != 1    # continue condition

Regards,

Brian.