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Is there a good RPN calculator currently? The HP Prime is lacking apparently, and the 50G is no longer available (and a bit old)
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> has no ambiguous instructions Really? What do you call an operator applied to an empty stack? A sequence of commands that leaves the stack non-empty? I don't see why that's any less ambiguous than mismatched parentheses.
Why would any person or machine care that the stack wasn't empty?
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For whatever reason my high school had HP48s for my junior year math class, which got replaced the following year for TIs since “that’s what you’ll be using in college”. I much preferred the RPN and ended up convincing my parents my life would be easier with a new HP49g (which wasn’t a lie, it was). That thing helped get me through my math major and I’ll always remember my old school professor who taught my complex a…
The HP48s has a much nicer keyboard than the HP49g though! HP48gx may have been a suitable upgrade instead :)
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Well, it’s easier to build because it has a terse syntax that requires fewer symbols, doesn’t need precedence and associativity rules, and has no ambiguous instructions. It’s easier to use for the same reasons.
> has no ambiguous instructions Really? What do you call an operator applied to an empty stack? A sequence of commands that leaves the stack non-empty? I don't see why that's any less ambiguous than mismatched parentheses.
That’s actually a feature. It’s even fundamental in concatenative programming languages such as FORTH and Factor.
It's simpler to implement RPN than algebraic notation with precedence. The latter requires an operation stack where operations are stacked until they encounter a lower precedence operator or the user presses =. The user types less, the computer does a lot less. I find it fun to think in RPN.
Here’s the code:
https://github.com/ashok-khanna/RPN-31
Here’s the link:
Back in the early 80's Forth was the first language available on the original Macintosh. I loved Forth, but it completely ruins you for every other non-RPN language. I remember writing an ASCII terminal (dial-up modem) application in Forth to learn the language, and afterwards every other language that I was using at the time just looked... weird.
I had to perform a massive mental shift to get back into all of the other languages I was being paid to work with at the time, and it was so difficult (for me, anway) that I never went back to it.
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Well, it’s easier to build because it has a terse syntax that requires fewer symbols, doesn’t need precedence and associativity rules, and has no ambiguous instructions. It’s easier to use for the same reasons.
> has no ambiguous instructions Really? What do you call an operator applied to an empty stack? A sequence of commands that leaves the stack non-empty? I don't see why that's any less ambiguous than mismatched parentheses.
[Pi] for example is an operator which can push the value of Pi onto an empty stack.
There's an open-source Android app called Droid48 that gives you a virtual HP48, if you're into that sort of thing. I know when I'm out with coworkers and they whip out Droid48 to calculate the tip, I picked a good place to work.