Can there be a new feature for handling lookback exceeded?

For example, Script sets LookBack to 100. But in fact, 200 was required. So during cleanup(), the script will launch the same Zorro script (different instance), this time with Lookback = 200.

This can be useful for when all kinds of TA functions are mixed and matched, and it is difficult to calculate maximum lookback.

Isnt the needed lookback displayed in the error message?

Yes, but then I’d have to punch it in manually.

But imagine that I’m running a batch script where I input many variables at the command line. If a lookback error occurs, I can launch a sub-process that automatically corrects the issue with a sufficient memory allocation.

We could implement a variable that contains the minimum lookback after the initial run, and a method to restart by script. You can then set Lookback like this:

LookBack = max(100,LookBackMinimum);

Already done? Nice.

Quick question: If quit "+" is called, can the length of series calls change, or do I need to terminate the script to change the length?

So it looks like series length is determined during INITRUN but not allocated until FIRSTRUN:
https://zorro-project.com/manual/en/series.htm
Plus my tests seem to confirm that quit "+" allows me to change series length without issue. This is nice!

One more thing: there's a bug in this sample code from the manual:
https://zorro-project.com/manual/en/lookback.htm
quit(+) gets skipped because this can only be detected in Init. So more like this:

It's worth noting that invoking indicator functions to calculate lookback can still be problematic, even when restarting the script with quit(+).

Namely, if a vars of insufficient length is supplied to an indicator function, even in Init, this can cause many bad memory writes and strange errors. The workaround here is to supply a large dummy buffer during init only.

With which indicator does this happen? The indicators from the ta-lib cannot read past the lookback period.

That would require testing to determine, but I’d assume the ones from indicators.c.

Hmm. We could limit them also to the lookback period, but many are also used with general data arrays. This would then not work anymore. A large dummy buffer is maybe indeed the best solution, only question is how large it should be.