bug#40213: what-cursor-position could tell the meaning of marks too!

[Richard Stallman]

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  > > No worry, C-u C-x = (what-cursor-position) will tell you:
  > >
  > >  There are text properties here:
  > >    face                 gnus-summary-high-unread
  > >    gnus-number          31074
  > >
  > > Ahhh... alas it could tell you more!

  > I think that's pretty much impossible -- there's no infrastructure in
  > Emacs to have it tell you what a random character in a generated buffer
  > means.  And adding a bunch of text properties everywhere just in case
  > you wonder would be impractically slow.

Here's a way that is trivially easy to implement, and won't be slow.
Invent a new text property: 'significance'.  If the character
has that property, its value should be a string which explains
what the character "means" in that particular case.

If a mode puts some sort of special marker in a buffer, it can
put that text property on it.


This is trivial to implement because it requires no code.
C-u C-x = will display the text property anyway ;-}.


-- 
Dr Richard Stallman
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)