Re: Reliable after-change-functions (via: Using incremental parsing in Emacs)

[Stefan Monnier]

> AFAIU CC Mode could actually eliminate it, but that would require
>  a significant rework of its internals.

My experiments to make CC-mode use syntax-propertize-function suggest
that it wouldn't require too much work, actually.  For an outsider, it's
difficult because it's hard to understand all the invariants/assumptions
in the current design, but if Alan and I were to work together on it, it
would be pretty easy.  So far Alan has been opposed and there are several
good reasons for that:

- it's extra work.
- it will inevitably introduce bugs.
- while it will most likely be faster when opening the file, it will
  likely be slower in other cases (e.g. when modifying the buffer near
  point-min in one window while having point-max displayed in another).
- syntax-propertize was introduced in Emacs-24 so it would require
  either dropping CC-mode's support for earlier Emacsen, or adding some
  compatibility layer (I think this compatibility layer would be
  easy to write but would likely not cover all cases).

> I'm not saying that nobody should try to explore how to decrease the delay,
> and what tradeoffs come with that. But for now, I think, we should encourage
> our kind volunteers to just implement integration the way TreeSitter's
> authors expect it. And try, on our side, to provide the best tools for
> it. Then we can see how well it does or doesn't work, and what are the
> biggest annoyances that the users have with it.

+1


        Stefan