Do you know how whitespace mode turns on the visibility of certain normally non-visible characters, such as the space and the tab? Well, I'd like to be able to emulate this with Unicode bidirectional characters (e.g. Right-To-Left Mark U+200F, Pop Directional Isolate U+2069).
One way to make, say, the Right-To-Left Mark visible, is to put the following lines in the .emacs file:
(unless standard-display-table
(setq standard-display-table (make-display-table)))
(unless
(aref standard-display-table #x200F)
(aset standard-display-table #x200F (vector (make-glyph-code #x22c9 'escape-glyph))))
The problem with this approach is that it keeps the mark visible all the time. I'd like a way to turn its visibility off, and then possibly on again later on.
This question is related to this one. The difference is that in the present question I'm not asking to turn the feature on only in whitespace mode, but rather to turn it off and on in the current mode, whatever it be. Hopefully this is an easier question to answer.
