Folding: Design Criteria, draft

[Tony Balinski]

Quoting Aaron Hsu <arcfide at sacrideo.us>:

> Also, once folded, BBEdit uses a simple "(...)" looking object to denote
> the folded region, and I like that. There is another method, like Emacs,
> where you can actually hide any selection of code, but I don't think
> that's the way to do code folding in this case.

Agreed. I would like to see the visual representation programmable too (by
macro) so that it could contain commentary, but with a default (that cannot be
zero-width). Visually, the marker must stand out always. Making appear as a
shaded button (motif-like) would make it stand out from the simple text
coloring we have just now. An indicator in the line-number or extra gutter
would be nice too.

> I also notice that you seem to think that folds on a per line basis are
> more common? Well, most of my experience is with BBedit, and in that,
> folds are between any two arbitrary points in the code, and it should be
> possible to fold at any arbitrary selection, and have it turn into a
> little (...) object or some such. :-)

Agreed again. Arbitrary folding should be allowed. Folds should be able to
contain other folds, but if a fold start position is inside another fold, the
outer fold also contains its end position, ie no overlapping of extremities.