> Date: Sat, 13 Apr 2013 13:24:13 +0100 > From: "Sean O'Halpin" <sean.ohal...@gmail.com> > Cc: Carsten Dominik <carsten.domi...@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.