Can we have RPN back?

[orcinus]

(01-26-2014 07:47 PM)Tim Wessman Wrote:  1. How would a command line be treated since you can have multiple things together at a time (vs a single numerical only item)? If you are replacing the item in level 1 as you write it....
2. How would it behave in places like an input form or dialog where you have no stack?
3. How would algebraic objects be used?
4. How specifically would it work for all possible object types (numbers, complex, vector, matrix, list, string, algebraics,etc)?

I'm a bit late to the party, but...

The answer to all of these is simple - it *should* behave like it has since hp48. Namely - like RPL.

1. Entering << 1 1 + >> in a command line should yield 2. Entering 1 1 + should result in an error. Entering '1+1' should result in 2.

2. But there is a stack. There is *always* a stack, that's the whole point of RPN and RPL. You might not *see* the stack, but commands are always pushed on a stack and popped off it when executed - entering << 2 pi * sin >> should push 2 and pi on the stack *internally* then perform multiplication on levels 1 and 2, then perform sine on level 1.

3. See 1. Single quotes.

4. I don't understand the question. Like it always has. Objects are tokenized and recognized as such based on certain delimiters (various brackets) and then pushed on the stack. Like they always were