Re: `isearch-allow-scroll' - a misnomer and a bad design

[Alan Mackenzie]

Hi, Stefan.

On Fri, Sep 09, 2011 at 08:58:42PM -0400, Stefan Monnier wrote:
> > I meant that it is not _necessarily_ about scrolling.  I understand that 
> > that
> > was the original motivation, and it remains an important use case (for 
> > people
> > who want scrolling).

> Actually, it's more than that: its intention is about scrolling.
> You can abuse it, but some people like pass-through for some set of
> commands but not for others, so isearch-allow-scroll is meant to control
> that for scrolling commands.

> We all agree that the fact that C-u got folded into it is definitely
> a misfeature in this respect.

I do not agree with this.  ;-)  The prefix arg is an essential part of
the command with which one might exit isearch.

> Maybe what you want is a new option `isearch-pass-through-categories',
> which would be a list of symbol properties, so any command who has
> a non-nil value for one of those properties is allowed to run without
> exiting isearch.

> Then `scroll-command' becomes one possible element of
> isearch-pass-through-categories.

> > It is true, AFAICT.  Nothing prevents you from putting property
> > `isearch-scroll' on *any* command, to get Isearch to pass through
> > to it.

> But you still only have one boolean value to control what commands to
> pass through.

This isn't quite true either.  The current isearch-scroll property must
be t (not merely non-nil) at the moment.  This leaves other non-nil
values to specify other behaviour.  This was deliberate.

> So what would you name this boolean option?
> `isearch-a-few-more-commands-run-within-isearch'?  What if people want
> pass-through for scrolling commands but not for your new command?


>         Stefan

-- 
Alan Mackenzie (Nuremberg, Germany).