newRPL: Angles revisited

[Claudio L.]

(03-31-2016 06:49 PM)Han Wrote:  Something to consider:

When writing, we write from left to right (most of us). So when you write ∡90° 1 + --> ∡91° it makes sense as the angle appears "first", and one can easily deduce that the type of "first" argument takes precedence. However, on a stack, the data-value entered last is actually "first." While I don't really care either way, I just thought it might be something to consider when finalizing the type priority.

You're right, let's clarify:
I always call first argument to the left argument in a binary operator, and second argument the right argument.
I never refer to the arguments by stack level number.

(03-31-2016 06:49 PM)Han Wrote:  Also, is it safe to assume that the tag/unit gets dropped when used in operations that would normally either not make sense or not take angles as arguments? For example, what would ∡12° 2 ^ produce as a result? Should it be ∡144°, or perhaps some sort of "squared" angle if we are treating the value as a unit, or simply the number 144?

Good point, I think besides addition and subtraction, all other operations should produce real numbers as results, as they don't make any sense with angles.
For example, ∡12° 360 / is no longer an angle, but a fraction of a turn, so it makes sense to forget about the angle tag. If you really need to keep track of the angle through an expression like this, you should use units instead.
However, adding and subtracting should preserve the format of the first (left) argument.