Re: Emacs and Gnome Canvas

[Eli Zaretskii <eliz@gnu.org>]

> From: Óscar Fuentes <ofv@wanadoo.es>
> Date: Thu, 15 Jul 2010 19:48:50 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> I know from the start that the stuff I'll use *if* the plan goes
> >> ahead is not acceptable for key Emacs developers
> >
> > Why the defeatism?
> 
> I would use Qt, hence C++, not being shy about using advanced language
> features if necessary. That is for getting a working system as soon as
> possible.

C++ is not the fastest language to get a job done.  Plus, you'll have
unrelated job on your hands of making Emacs C++-compliant, as
discussed in another thread.

Unless you are rewriting the whole Emacs, that is ;-)

> > How you will be able to implement a new display engine without at
> > least some familiarity with what the current one does?
> 
> I expect that if the internal layout of the data to be displayed is
> clear enough, that is sufficient for the display engine writer. I mean,
> knowing "this represents a text property" is what you need. Knowing how
> the current display engine deals with it shouldn't be necessary.

I said "knowing WHAT the current does", not HOW it does that.  The
problem is, you cannot know WHAT it does without at least some study
of the code, because there's no requirements document.

Take the font-lock, for example -- it has special support in the
display engine.  Without implementing the APIs for this support, JIT
Lock, which is standard since Emacs 21.1, will not work.