Free42 with big stack, test version

[Thomas Okken]

Despite the new Allow Big Stack setting, I'm still considering other options for peaceful coexistence of 4STK and NSTK. They will just be provided in addition to the current functionality, not instead of.

Disabling the big stack completely by default makes sense because HP-42S compatibility is a central aspect of Free42, and that is something which many users require. So that will stay in place regardless of whatever else I come up with.

But for people who are interested in using both modes, an additional "allow big stack, but automatically switch to four-level stack if..." mode would probably be useful. Details to be worked out. What should the "if" condition be? A program not tagged with BIGSTK in line 01, or a program containing LBL instructions instead of NLBL, or something else? And if the automatic switch takes place, should it be permanent or temporary, 4STK or L4STK?

I suppose there may not be one single best answer to this, it will depend on how one intends to use this feature, the specifics of each user's workflow. I'll hold off on implementing anything further until I have a better idea of what would actually work well in practice.