|Re: RPN/RPL - What?|
Message #10 Posted by Valentin Albillo on 10 June 2003, 1:12 p.m.,
in response to message #7 by jimc
"I am not a programmer by nature or by occupation. I just want an answer."
That's exactly my point. Classic HP calculators programmable in RPN were designed as tools for technical professionals, like engineers for example, who weren't programmers nor did they want to be, they just needed answers. Simple keystroke RPN programming provided those answers easily and fast.
On the other hand, RPL is a full-fledged, complicated, object-oriented language, which requires the user to deal with the vagaries and complications necessarily associated with such an OOP language, thus negating all simplicity and requiring its users to become what they'd rather not.
The result ? A divided user base, some loving RPL, some hating it, to the benefit of noone. Most technical users would find RPL unsuitable to get solutions fast, and would look elsewhere, ultimately dismissing RPL for good. The RPL revolution would gain only a very small percentage of people anew, while losing a lot of old timers. Most people saw the HP48/49 machines as "already too complicated" and they indeed are. I'm still waiting for someone to claim that any given RPN machine is "too complicated". Even the HP-41CX, with its large instruction set, its many ROM modules, and even its synthetics, still remained perfectly 'understandable', easy to grasp and use. Try that with an RPL machine.
I really feel classic RPN realized the best compromise between simplicity and power, with its 4-level+LastX RPN stack. Three or two level would be insufficient. More than 4 levels would be a book case of diminishing returns. Throwing it all in exchange for infinite levels which could also unexpectedly become three, two, one, or none (!), with no automatic replication, with an overblown "last x" which could also be non-available, with all store operations now forced to always being indirect, etc, etc, was too high a price to pay for the loss of simplicity and convenience.
In the end, it caused most customers to completely ignore (and dislike) RPL, and RPN suffered as well. Every paradise has its snake.
"BTW, if anyone could point me to a GOOD reference to learn RPL from (ideally from the 'net), I'd really appreciate it!"
IMHO, this is the best, easiest, clearest book on the subject for learning purposes, assuming an user proficient with RPN but not versed at all in RPL:
"HP 48 Programming Examples" (HP Press Series) by Donald R. Mackenroth, paperback, 341 pages, Addison-Wesley
December 1991, ASIN: 0201563258)
It includes lots and lots (more than 100) sample programs of all kinds, thoroughly explained and commented by the author, who, BTW, also wrote the excellent HP-25 Owner's Handbook, among others.