history of the 4-level stack

[axd1967]

Quote:It is a kind of sadism to program stack manipulation over lets say six stack places (with my preferred HP 50g).

As Walter writes, it doesn't really matter how much is on the stack; all that matters is the few arguments that the current subroutine needs, and what arguments it is expected to put on the stack before quitting. Because routines can call each other (even recursively), they will add their layers of temporary objects on the stack, but if well written, they will only leave data behind that the caller needs.

A casual user might indeed get lost when interrupting an app that is running deep in calls, but that doesn't matter from the perspective of each routine.

So a well written app should end with no garbage left on the stack, only with the expected output.