Re: Advice on troubleshooting function to "unscroll"

[Marcin Borkowski <mbork@wmi.amu.edu.pl>]

On 2015-01-26, at 01:03, Drew Adams <drew.adams@oracle.com> wrote:

>> why did scroll-up-command work where the still useful but not
>> appropriate scroll-up did not?
>
> That was already answered, and I thought that you understood
> the answer.  The problem was that the code checked whether the
> current command was `scroll-up', and it of course never would
> be.  `scroll-up' is called by `scroll-up-command', but only the
> latter, never the former, is invoked by you interactively, i.e.,
> as a command.  Variables `this-command' and `last-command' are
> only set to functions when they are invoked as commands.

I think the OP did understand this, but meant to ask (more or less) "why
weren't the Emacs Devs satisfied with scroll-up, which did work after
all".

>> And if I'm being honest about why I did not go to Edebug it's because I
>> was anticipating great difficulty reading the backtrace statements.  I
>> thought my problem might be compounded by a more general illiteracy in
>> that regard...
>
> The Emacs manual sends you to the Elisp manual, node `Edebug',
> for information about using that debugger.  That section of the
> Elisp manual is like a mini-manual about Edebug.
>
> Why it does not send you instead to the Elisp manual node
> `Debugger' (which has title "The Lisp Debugger"), I don't know.
> That node covers the regular debugger (i.e., `debug').
>
> `debug' is older than `edebug'.  Perhaps the person who wrote
> `edebug' decided to send readers of the Emacs manual to learn
> about Edebug. ;-)
>
> (In older versions of Emacs, e.g. Emacs 20, there was no link
> from the Emacs manual to the Elisp manual for either the regular
> Lisp debugger or Edebug, but there were multiple mentions of
> using the former - and only no mention of Edebug, except to say
> that edebug.el was contributed by Daniel LaLiberte.)

Drew, your answer is (as usual) very helpful and informative.  Thank you
for your insights and the bits about Emacs history.

I think we really need Sacha Chua to do an Emacs Chat with you.  I,
personally, would love to learn a bit about your workflow and Emacs
config.  (Not that I would necessarily like to copy it: I strongly
disagree with you on the window/frame issue, for instance!)

Regards,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University