Swap the last two expressions in RPN mode with the right arrow key

[ebourg]

Hi, as an old HP 48GX user I really enjoy the Upsilon RPN mode, however I miss a minor feature that I used a lot : on the HP 48 the right arrow key swaps the last two values of the stack:

Would it be possible to implement this feature in Upsilon too?

[Yaya-Cout]

You can already swap with the parenthesis (left to swap last three values, and right to swap last two values).
Arrows are already used for navigation, but I don't know of it's really useful to navigate in the RPN input (you will probably write at most 3 characters, so you can probably erase to edit instead of using arrows) but then it won't be consistant with the rest of the interface (anyway, RPN is already a bit special for navigation).