|Algebraic, RPN... Pick one.|
Message #9 Posted by Vieira, Luiz C. (Brazil) on 25 June 2002, 10:25 p.m.,
in response to message #8 by Christof (Davis, CA)
may I point some things out?
Since the very appearance of the HP28 (C, remember?), the algebraic X RPN/RPL quiz became one of my personal battles. Which one to use? (a bit off topic, but more than that, defining our own unit as a new algebraic object amused me, too)
When I write programs for any RPL calc I use as much algebraic as comprehension is required, so I myself am able to understand my own programs later. Using algebraic expressions as program resource is, sometimes, a must. I completely agree with many contributors in here that state that extensive use of RPL, mostly stack manipulations, will cause a program to be unreadable and hard to understand. I have programs written some years ago I cannot easily change or add features, because I simply do not remember what the h... that ROLLD or PICK use as parameter, so I must step through almost all the program to get to the point and find out the parameter value. Gee!
And when previous stack contents are needed and the programmer (me) did not use local variables? Who in Heaven can tell? If a simple
<< -> A B C << .... >> >> is there, no matter at all! In this case, using
value [ENTER] value [ENTER] value [ALPHA] [ALPHA] program_name [ENTER] is easy. Also, using algebraic feature (since the HP28), we have:
[ALPHA] [ALPHA] program_name[(] value [SPC] value [SPC] value [ALPHA] [ENTER]. Both will work fine. What matters is, for me, how to handle them inside the inner << and >>.
When only 4-plus-1 level RPN calcs were available, anything should "chronometrically" fit in the stack. Debugging was easier, mostly because T-values were simply lost OR duplicated (how I miss this duplication sometimes...). Some new RPL features for handling objects in the stack are very important tools, but also more data to process (in our brain).
Wanna know? The fact is that programming them all is still funny. After all.
Comments? Corrections? All wellcome.
(Hey, Mr. Belillo; proud of me?)