Why act from point forward by default, instead of whole buffer?

Why act from point forward by default, instead of whole buffer?

[Drew Adams]

General question that occurred to me while reading thread "keep|flush-lines,
how-many to be used backward": What is the advantage of having such commands
(`keep-lines' and many others) act, by default, from point forward instead
of (by default) on the entire buffer?

They do act on the region, if it is active, so that's good. But why not have
the entire buffer be the default if the region is not active? I use that
behavior for many commands I define.

(defun region-or-buffer-limits ()
    "Return the start and end of the region as a list, smallest first.
If the region is not active or is empty, then use bob and eob."
  (if (or (not mark-active) (null (mark)) (= (point) (mark)))
      (list (point-min) (point-max))
    (if (< (point) (mark))
        (list (point) (mark))
      (list (mark) (point)))))

I also have keys that select the region before and after point, in case I do
want to act on that text.

Re: Why act from point forward by default, instead of whole buffer?

[Davis Herring]

> General question that occurred to me while reading thread
> "keep|flush-lines,
> how-many to be used backward": What is the advantage of having such
> commands
> (`keep-lines' and many others) act, by default, from point forward instead
> of (by default) on the entire buffer?
>
> They do act on the region, if it is active, so that's good. But why not
> have
> the entire buffer be the default if the region is not active? I use that
> behavior for many commands I define.

Not everyone uses Transient Mark mode.  If they acted on the whole buffer,
you would have to use narrowing to restrain them in any way.  By acting
forward, one common case can be handled with no prefix, and the whole
buffer with just M-<, and narrowing (again) otherwise.

Davis

-- 
This product is sold by volume, not by mass.  If it appears too dense or
too sparse, it is because mass-energy conversion has occurred during
shipping.

RE: Why act from point forward by default, instead of whole buffer?

[Drew Adams]

> > General question that occurred to me while reading thread
> > "keep|flush-lines, how-many to be used backward": What is
> > the advantage of having such commands (`keep-lines' and many
> > others) act, by default, from point forward instead
> > of (by default) on the entire buffer?
> >
> > They do act on the region, if it is active, so that's good.
> > But why not have the entire buffer be the default if the
> > region is not active? I use that behavior for many commands
> > I define.
>
> Not everyone uses Transient Mark mode.  If they acted on the whole buffer,
> you would have to use narrowing to restrain them in any way.  By acting
> forward, one common case can be handled with no prefix, and the whole
> buffer with just M-<, and narrowing (again) otherwise.

Good point. So the current behavior is there to fit the default behavior of
not having transient-mark mode on.

We should change the default anyway, so transient-mark mode is on. We've
discussed that before, but the battle has not yet been won. After it is,
perhaps we can revisit this question, since the only reason given (so far)
for this behavior is to fit non-transient-mark mode.

RE: Why act from point forward by default, instead of whole buffer?

[Davis Herring]

> We should change the default anyway, so transient-mark mode is on. We've
> discussed that before, but the battle has not yet been won. After it is,
> perhaps we can revisit this question, since the only reason given (so far)
> for this behavior is to fit non-transient-mark mode.

Even if transient-mark-mode becomes the default, the reason remains valid,
because there will still be people who do not use it.

Davis

-- 
This product is sold by volume, not by mass.  If it appears too dense or
too sparse, it is because mass-energy conversion has occurred during
shipping.

RE: Why act from point forward by default, instead of whole buffer?

[Drew Adams]

> > We should change the default anyway, so transient-mark mode is on. We've
> > discussed that before, but the battle has not yet been won. After it is,
> > perhaps we can revisit this question, since the only reason
> > given (so far) for this behavior is to fit non-transient-mark mode.
>
> Even if transient-mark-mode becomes the default, the reason remains valid,
> because there will still be people who do not use it.

Not if the reason is that this is so _because it is the default_.

Depending on which is the default behavior, and whether you use that
behavior or override it, one or the other behavior here (current or what I
proposed) will appear beneficial.

At least that's my argument. You are saying that the current behavior is
fitting for use with non-transient-mark mode. And I am saying (and I think
you agreed, but I'm not sure) that the behavior I proposed is fitting for
transient-mark mode.

Re: Why act from point forward by default, instead of whole buffer?

[Richard Stallman]

    General question that occurred to me while reading thread "keep|flush-lines,
    how-many to be used backward": What is the advantage of having such commands
    (`keep-lines' and many others) act, by default, from point forward instead
    of (by default) on the entire buffer?

    They do act on the region, if it is active, so that's good. But why not have
    the entire buffer be the default if the region is not active? I use that
    behavior for many commands I define.

It is historical tradition and I would rather not change it.