List Commands Library for 50g

[DavidM]

(07-04-2017 08:41 PM)Gilles59 Wrote:  An exemple of DOPERM to solve cryptarithms
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That's a very good example of how to make use of DOPERM, Gilles! Unfortunately, it's also a very good example of why I need to go ahead and do something I was already thinking about: creating some kind of mechanism for an early exit feature. It pains me to think that you had to resort to a KILL command. Ouch.

While I am loathe to do anything that will slow down these commands, I think the potential benefit from building in the early exit checks will outweigh the (hopefully) slight delay.

This becomes a bit more complicated because DOPERM, like the PERM command, is actually both a combination and permutation processor. That means that there's two distinctly different "early exit" concepts: one for the current combination being permuted, and the other for the entire process. My plan is to have two local flags available to the user -- ENDPERM and ENDCOMB. Those will only be available while the command is running, and will be initially set to 0/FALSE at the beginning of operation. If the user program changes either of them to 1/TRUE, DOPERM will respond as follows:

ENDPERM TRUE: All processing will stop and the command will exit gracefully, placing the output of processing into a list as usual.

ENDCOMB TRUE: Any further permutations of the current combination will be skipped, and the next combination will be started for permutation processing.

Does this seem like a reasonable approach? I'm open to other suggestions for how to manage this. While it seems like this should be workable, I don't presume that it's the best way to handle it.

All thoughts are welcome!