Re: Shift selection using interactive spec

[Thomas Lord]

Lennart Borgman (gmail) wrote:
> I translate it to something like this in elisp code:
>
> ;;;; pre-pre
> ...

There's no need for a pre-pre hook or
for a test of whether the last sequence
was shifted.   You're using the "three variables"
correctly, but there are simpler ways to use them
to achieve the same effect.



> ;;;; post-post
> ;;
> (if buffer-was-changed
>     (setq preserved-tm nil)
>   (unless preserved-tm
>     (when user-wants-it
>       (setq preserved-tm maybe-preserved-tm))))
> (setq tm preserved-tm)


No.   "buffer-was-changed" has nothing to do with
anything here.  Sorry.   Nor is there any need
for a "post-post" hook.   The command loop can
simply, unconditionally, copy tentative-mark to
maybe-preserved-... before running a command,
and preserved-... to tentative-mark before returning
control to the user -- two unconditional "setq"s in
the loop.   None of this "buffer-was-changed" stuff.
Those distinctions happen elsewhere in this scheme,
and on a different basis.

-t



-t