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

[Stephen J. Turnbull]

PJ Weisberg writes:

 > The problem is that you've defined "scrolling command" to mean something
 > that has nothing to do with scrolling (i.e., commands which MOST DEFINITELY
 > DON'T exit isearch).

No, that's completely wrong: there must be no buffer changes, no point
movement, some other conditions.  Exiting isearch or not is not part
of the definition of "scrolling command".  The fact that the current
defintion doesn't mention "movement" of anything is a bit odd, indeed,
but such things are occasionally useful.

One might want to define an additional class of commands that satisfy
those restrictions but aren't scrolling commands (ie, adjusting the
position of the window with respect to the buffer).  If so, define the
classes (including adjusting the definition of "scrolling command")
and adjust the code to recognize them.  But:

 > This leads to ridiculous conclusions such as "C-u
 > `universal-argument' is a scrolling command in its own right."

`universal-argument' is a meta-command, of which there are very few,
so adding it (and other such meta-commands) ad hoc to "scrolling
commands" might be the pragmatic way to handle it.

What other commands conform to the restrictions that Alan stated?  Of
those, which would you like to add to the class that inhibit isearch's
normal exit behavior?  Are there whole classes of them that users
would like to enable (or disable!) as a group, or a bunch of isolated
commands that different users are likely to express varied willingness
to enable them?