[Jprogramming] Repeated application of a verb

[David Vaughan]

Well, the idea is to repeatedly perform the verb on its own output until one of two outputs occur, at which point the verb should stop being performed. Also, I need to have some way of knowing which of the two outputs were achieved. The result of the verb on each application will a positive integer. Does this sound like ^: would be of use? If so then how should it be applied? If not, then what would be the best approach?
Thanks.



On 8 Oct 2011, at 13:04, Raul Miller wrote:

> On Sat, Oct 8, 2011 at 6:23 AM, David Vaughan
> <purpleblues13 at googlemail.com> wrote:
>> Hi, I am looking to repeatedly apply a verb on itself until a
>> certain value is reached, with the prior knowledge that there are
>> two values that can be reached. The idea is to count how many times
>> one of the two values comes up. I know about the power verb but I'm
>> not sure how to use it properly beyond the simple v^:n y form. I've
>> read about using it like a C while loop but in my case, there are
>> two values I want to 'exit the loop' with.
>> 
>> Any pointers? Thanks.
> 
> Depending on what specifically you are trying to do, ^: may or may not
> be the right thing to use.
> 
> The issue is that ^: assumes that it is dealing with a mathematical
> function.  If its function gives the same result twice in a row, it
> will stop right there.
> 
> This is how ^:(test)^:_ works something like a while loop -- when
> (test) returns false, the inner ^: becomes an identity function and
> the outer ^: knows that it's time to stop.
> 
> That said, note that ^: functions -- like pretty much everything else
> in J -- can take list arguments and produce list results.
> 
> -- 
> Raul
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