Re: cc-mode fontification feels random

[Theodor Thornhill <theo@thornhill.no>]

Ergus <spacibba@aol.com> writes:

> Going a bit more into this. And reconsidering tree-sitter.
>
> As there is already a tree-sitter module package with some interesting
> functionalities. (I know Eli didn't like some details in it's
> implementation)

This module us used by csharp mode, in its own
`csharp-tree-sitter-mode`, and uses these packages from melpa:

 - tree-sitter-mode
 - tree-sitter-langs
 - tree-sitter-indent

This bug (https://github.com/emacs-csharp/csharp-mode/issues/164) is an
even simpler test of the performance from CC Mode, which alan _is_
addressing right now, but should be interesting given this thread.
csharp-mode grinds to a halt here, but csharp-tree-sitter-mode handles
this perfectly.

As for correctness there is no comparison.  The tree sitter variant
covers things that aren't even possible using CC Mode variant, like
string interpolation, complicated, nested generics, preprocessor
directives and much, much more. 


@Stefan - I'm not sure I understand what you mean by troublesome for
elisp hackers.  These grammars have a lisp-like dsl, and is pretty
usable through C-M-x and defvars, see:
https://github.com/emacs-csharp/csharp-mode/blob/master/csharp-tree-sitter.el#L44.

IME experience it's not the same as normal elisp hacking, but it's good
enough.  That's only an opinion though.

I don't understand why this shouldn't be doable? There could be an nongnu-ELPA
package with defined grammars, and a way to download and compile
parsers.

As a side node, it is easy to design structural editing also, like
`delete-defun` `change-in-string`, `beginning-and-end-of-defun` etc.

Just take a small look at
https://github.com/emacs-csharp/csharp-mode/blob/master/csharp-tree-sitter.el.

These 410 lines covers way more than what CC Mode is atm.  It would be
*great* to move the tree sitter part to emacs.

Just my two cents :)

Theodor Thornhill