Re: Difference between 'C-x e' and 'M-x macro'

[Stefan Monnier]

> My question is: why?  What's the difference between 'C-x e' and 'M-x
> upmacro?'

Lots of things.  Some macros (like `previous-line' bound to `up') use
variables like `last-command' or `this-command' to determine the
name under which they are being run or which was the previous
command executed.  In your case, the second `upmacro' thinks that the
command executed just before was not `previous-line' but
something like `execute-extended-command' (bound to M-x) or maybe
`minibuffer-complete-and-exit' (bound to RET in the minibuffer
while entering the M-x thingy) so it behaves differently.

> Believe it or not, this difference effects an elisp program I'm
> currently working on.  Thanks,

The docstring for `forward-line' says:

   If you are thinking of using this in a Lisp program, consider using
   `forward-line' with a negative argument instead.  It is usually easier
   to use and more reliable (no dependence on goal column, etc.).


        Stefan