Plus42 algebraic expressions update

[Thomas Okken]

(02-25-2021 10:46 PM)rprosperi Wrote:  This beings up an interesting point - if the user has in fact created an RPN program and an equation with the exact same name, which would be used if invoked?

The easiest thing to do, and totally within the spirit of the HP-41C and HP-42S, would be to allow that kind of name clash and simply define which one wins. Duplicate alpha labels have always been allowed, and the rule is that the last one in memory is the one that gets called (being the first in the global chain, so the first to be found in the global label search). In that spirit, it would be perfectly fine to say that labels are searched first, and expressions second.

In practice, it may not even matter much. Labels are still going to be limited to 7 characters but equation names can be any length. The only reason why there is a 7-character name limit at the moment is that the CALC key in the equation editor is implemented by calling PGMSLV or PGMINT, and because of the way those invocations take place, the 7-character alpha argument length limit applies. But that limit could be worked around, and the internal variable where the current SOLVE or INTEG program name is stored could also be changed from <= 7 characters to unlimited. If people use long, descriptive names for equations, and short names for labels (even shorter than 7 characters in practice, if you want them to fit in a softkey label), name collisions need not be very common, I would hope.