goto

[Mike Meyer]

Peter Hansen <peter at engcorp.com> writes:

> Sybren Stuvel wrote:
>> Mike Meyer enlightened us with:
>>
>>>>I dislike gotos because it is too easy to inadvertently create
>>>>infinite loops. <10 WINK; 20 GOTO 10>
>>>
>>>And it's impossible without them? <while True: pass>
>> I thought the same thing, but then I read it again and thought about
>> the "inadvertently". As soon as you see a "while True", you _know_
>> it's going to loop forever.
>
> Unless it doesn't, of course:
>
> while True:
>      break

My "favorite" infinte loop with while is:

   i = 0
   while i < 20:
         do_process(i)

Note the prominent *lack* of any change to i here?

Oh, for:

    from i = 0
    invariant 0 <= i <= 20
    variant 21 - i
    until i > 19
    loop
        do_process(i)

which throws an exception at the beginning of the second loop.

      <mike
-- 
Mike Meyer <mwm at mired.org>			http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.