Re: [Emacs-diffs] master 29d1c72: Introduce new value t for compilation-context-lines to eliminate scrolling

[Alan Mackenzie <acm@muc.de>]

Hello, Eli.

On Sun, Aug 25, 2019 at 22:37:39 +0300, Eli Zaretskii wrote:
> > Date: Sun, 25 Aug 2019 19:06:37 +0000
> > From: Alan Mackenzie <acm@muc.de>
> > Cc: emacs-devel@gnu.org

> > > 2- Why insert a prefix string (an "inserted arrow") instead of using
> > >    a "regular overwriting arrow"?

> > Because the overwriting arrow would obliterate the first two characters
> > of the file name.  I actually tried this first, and it wasn't
> > satisfactory.  This contrasts with another use of the overwriting arrow
> > in edebug, where (usually) only WS gets overwritten, and it is important
> > not to disturb the visible indentation.

> Did you consider to use the display margin instead?  You can have an
> overlay display in the margin by putting a 'display' property on the
> overlay string.  The advantage of using the margin is that it will
> keep the buffer text aligned.

Yes, indeed.  Thanks!  I wasn't actually aware of this facility (despite
seeing it many times in gdb).  As soon as I get my head around the
documentation (using the margin seems to be a bit twisted, somehow), I'll
amend the code to use it.

Should I have been aware of this?  Somehow, in the elisp manual, it seems
buried under several levels of chapters, sections, and sub-sections.

-- 
Alan Mackenzie (Nuremberg, Germany).