🚀 go-pugleaf

On 8 Jan 93 00:58:20 GMT, shibuya@bl.applicon.slb.com (Hiroto Shibuya) said:

shibuya> I just came across a fundamental difference between Emacs and
shibuya> VI, which I never noticed for a decade.

shibuya> THEY SCROLL UP/DOWN IN DIFFERENT DIRECTION!

This is not quite a correct statement. There is no difference.

shibuya> Emacs command "scroll-up" scroll the text up so you see the
					  ^^^^^^^^
shibuya> text further down.  VI command ^U, is described in the manual
shibuya> as "scroll up", which scroll the text down so you see the text
				      ^^^^^^^^
shibuya> further up.

What happens really, and none of the people in the followups I have read
has pointed this out, is that Emacs scrolls the *text*, and vi scrolls
the *screen* (window).

The visual effect is on the intersection of the two (the current page);
if you move the window up, holding the text still, you see the preceding
page, and if you move the text up, holding the window still, you see the
following page.

References:

In emacs if you "(describe-function 'scroll-up)", you get:

	scroll-up:
	Scroll text of current window upward ARG lines; [ ... ]
	       ^^^^

If you "man vi"  you get:

          <CTRL/U>     Pages up half screen.
--
Piercarlo Grandi, Dept of CS, PC/UW@Aberystwyth <pcg@aber.ac.uk>
  E l'italiano cantava, cantava. E le sue disperate invocazioni giunsero
  alle orecchie del suo divino protettore, il dio della barzelletta