bug#18697: 25.0.50; [PATCH] hi-lock interactive functions now default to the active region, if there is one

[Drew Adams]

> > What IS pointed out in that thread is that there are other ways
> > to pick up text at point, besides using the active region.  And
> > that gives you much more flexibility than hard-wiring the region
> > content as the default value.
> 
> Not *THE* default value, but a list of several default values
> where the active region is its second default value
> (coming after the symbol at point in that list).

Ah, OK, if that's what you meant.  Yes, a user should be
able to choose that, by cycling - at least in some contexts
(see below).  No, in general it should not be the _default_
default value. ;-)  That is, it should not be the first in
the list.

Even so, it would be good for a command for which the active
region defines the command scope to be able to easily exclude
that value from the defaults list, as it makes no sense in
that context.

IOW, my argument still holds: It is not always the case that
it makes sense for a default value for `read-regexp' to be
the content of the active region.  Sometimes it makes a lot
of sense.  Sometimes it makes _no_ sense.  And sometimes it
can make a little sense - a nice-to-have-available choice.

What `read-regexp' is used for depends on the context.
That context (e.g. a particular command) determines whether
and how much it makes sense for the active region to be
used as a default value.

Again, `read-regexp' is a utility function.  Its use cases
are many and varied.