OpenEuphoria

Anyone with reverse polish notation experience?

• Posted by Pete Lomax <petelomax at blueyonder.co.uk> Mar 11, 2003
• 515 views

I'm parsing (prefix) expressions and getting reverse polish notation
out. The question I have is at the point of pushing a postfix operator
on a stack, clearly *all* the necessary pre-calculations will have
been done. Should be a no-brainer, but I'm doing it register-based
rather than stack-based.

I'm adamant about prefix; eg add(3,4) instead of 3+4

Maybe later I'll get my head round infix.... (Guess I could stomach a
link which makes me confident enough to do both in v0.1, rather than
as I am just trying to get it working...)

My question at this point is: Has anyone a difficult prefix-only
expression hard to parse; rpn which worked unexpectedly, and/or any
pointers which may save me some time?

Eg: add(add(3,4),add(5,6)); not: (3+4)+(5+6)

Equally, does anyone have an expression they feel would be hard to
express in prefix rather than infix notation?

Thanks,
Pete