tricky - undo function - planning info

[gnuist006]

Hi All.

Normally M-x undo would undo each step. A function may comprise one or more 
steps. When a function is applied, and then undone, it is not clear how many 
steps of undo are really needed. This is really a very basic need and should 
have been addressed - and solved decades ago. I am looking for a good plan of 
what to do to achieve this functionality and basic facility. For example, 
something from the interpreter needs to be accessed about each function 
executed to indicate its number of elementary steps and this data stored 
elsewhere so an undo-function can be applied without any bugs.

Then again, maybe it is already implemented and undocumented, or there is a 
simple solution.

Bolega