Re: Enriched/Org is a colorful Org

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 13 Apr 2013 13:24:13 +0100
> From: "Sean O'Halpin" <sean.ohalpin@gmail.com>
> Cc: Carsten Dominik <carsten.dominik@gmail.com>, Org Mode <emacs-orgmode@gnu.org>
> 
> In your opinion, would it be possible to reproduce the functionality
> of outline-mode using text properties rather than overlays?

This needs to be analyzed.  Outline mode uses several features that
are specific to overlays, but not to text properties:
isearch-open-invisible and front-advance.  (It also uses 'evaporate',
but that happens automatically with text properties.)  I think
front-advance will happen automatically, but searching inside
invisible text is currently supported only for overlays (for reasons
that I consider irrelevant, but that's me).

> And in the case of org-mode, would this really make that much of a
> difference in terms of performance?

I don't know, because I didn't measure that, and neither did I see any
measurements published.  If there are many overlays in a buffer,
redisplay performance will certainly be better with text properties,
but I don't know whether this improvement will be significant: there
could be other factors at work that affect performance to a much
greater effect.  If we want to know for sure, there's no way around
profiling this.  Luckily, we now have profiler.el to help us.