BTW, a bit part of the font-lock and indentation rules is highly
dependent on the grammar being used and in addition to that, they're
likely mostly agnostic to the design of `indent-line-function` of
`font-lock.el`.
So it would make a lot of sense to try and work with other editors to
try and design an editor-agnostic way to provide that info, such that it
doesn't need to be re-done for each and every editor out there.
IOW I suggest looking at how Neovim/Atom/etc... specify that information
and see if/how we can reuse it. And if their format is not convenient
for us, try to work with them to design a format that can be convenient
for everyone.
Stefan