Re: Request for pointers and advice: displaying several buffers inside a single window

[Eli Zaretskii]

> From: Dmitrii Korobeinikov <address@hidden>
> Date: Sat, 11 Apr 2020 13:56:07 +0600
> Cc: Ihor Radchenko <address@hidden>, Yuan Fu <address@hidden>, 
> address@hidden, 
>       emacs-devel <address@hidden>
> 
> By "unified core interface", I meant something like an OOP-style
> public interface done in a way so the users don't have to know about
> the implementation and underlying data structures

You will find that in buffer.h.  Modify those interfaces, and you are
done.

> > > The good news is: I believe xdisp.c wouldn't have to be modified all
> > > that much if the regions are enforced to start on different lines.
> >
> > How so?  The display code accesses the buffer text directly, using
> > BYTE_POS_ADDR.
> 
> I didn't say it wouldn't have to be touched at all : ) xdisp.c has
> only 8 occurences of BYTE_POS_ADDR, that doesn't appear too bad.

Why does it matter how many times BYTE_POS_ADDR is used?  If you
change the implementation of BYTE_POS_ADDR, the replacement is a
mechanical job, no matter if there are 8 places or 800 to make the
change.