(RPL) percentage function % not preserving stack level 2

[cdmackay]

(01-06-2019 10:48 AM)Joe Horn Wrote:  cdmackay: No, that's not correct. During digit entry, one DUP in RPL has the same effect as a double ENTER in RPL, and has a different effect than a single ENTER, as can be seen in these RPL keystroke sequences:

CLEAR 5 DUP 6 % + --> 5.3 alone on stack
CLEAR 5 ENTER ENTER 6 % + --> 5.3 alone on stack [One DUP has same effect as two ENTERs]
CLEAR 5 ENTER 6 % + --> Error: Too Few Arguments [One ENTER fails]

Reason: RPL's ENTER *either* terminates numeric entry *or* performs a DUP, but never both at the same time, unlike the ENTER key in 4-level-stack RPN machines. Also, RPL does not have any "stack lift disable" feature. Hence the necessary differences shown above.

yup, got it, thanks! Although I think you meant to quote RMollov not me

thanks for clarifying anyway. I find it fascinating how such a simple question opens up some interesting design choices and helps me to understand the way the system works as a whole (well, a bit better, at least).