[yaantc]

Emacs is in the process of moving from legacy languages modes using regexps and elisp for syntax analysis to new modes using tree sitter.

In this context, what does a name like "c-mode" should mean? Options: 1) it should stick to the old mode, cc-mode here. To use the new mode, use explicitly c-ts-mode; 2) it should move to the new tree sitter mode, c-ts-mode. To use the old mode, use explicitly cc-mode; 3) it should mean the new preferred Emacs mode, with a way for the user to take back control if they have a different preference. This preferred mode will change at some point from legacy to tree sitter.

The change is (3), with a move to tree sitter in Emacs 30 (to be released soon) IIUC. It makes sense to me. Saying that anyone own a name as generic as "c-mode" in an open source project just because they're first and have a long history as a contributor (thanks by the way!) seems excessive. Change of default is normal in an evolving project, and as long as it's clearly documented with a way to override (which is the case IIUC) it's fine to me. One can dislike the change, but it's impossible to please everyone anyway. Emacs users are used to adjust configuration based on their preferences.

I understand it can be an emotional situation for the maintainer of the legacy mode. But I don't see the need to call foul play.

[juxtapose]

I agree with giving users control, but unfortunately I cannot agree with the move to c-ts-mode. And I cannot disagree more with associating CC mode with "legacy" when it's objectively better than the other alternative, at least currently. I don't think Emacs developers are doing users a favor in this specific case.

CC Mode is extremely capable. Over the years it has developed to such a maturity that almost all needs can be satisfied, and performance has never been a problem for me. It contains very few, if any, bugs, that affect my use.

On the other hand, the tree-sitter major modes are not at al production-ready to be considered as default. For one thing, the whole highlighting can break for complex macros and ifdefs. (I'd be glad to be enlightened whether it's theoretically possible to fix at all -- can you correctly highlight ifdefs without doing semantic analysis with the help of a compiler?) For another, CC mode has a feature called c-guess that can quickly analyze an existing source buffer and generate a format definition which proves extremely valuable. Alas, c-ts-mode has zero support for it.

I had high hopes for tree-sitter. I turned on tree-sitter modes for all my coding when it was out, and now I have zero enabled. They still have a long way to go and I don't want to spend time debugging emacs code at work. :-)

Tree-sitter is not a panacea. Fast parsing alone is not what makes a good major mode.

[fasa99]

As someone whose pronouns are C-programmer/vim, I feel unsafe.

My living nightmare would be to develop highly verbose Java programs in an editor with 999 gorillion different "modes" with seemingly random names.

"oh, you're making an singletonfactoryfacade in Treesat-19 mode, you'll need to be using CCC-mode, treesat-19 mode is for factoryencapsulationfactory patterns"

[shadowgovt]

And indeed, if anything, a project like emacs being unable to make a decision like this results in a project that slowly dies from the weight of its own history.

Tree-sitter is fairly universally understood now to be "the future." While cc-mode will likely have its place for a long time (hard to beat regexes on speed, even if they break down when the input is too noisy), moving the default to the tree-sitter implementation aligns with the other language modes going to tree-sitter. For good or ill, consistency is almost certainly better than new users having to learn "Your code is parsed by tree-sitter. Oh, except your C and C++ code, unless you set this flag, because Mackenzie threw a fit in 2024. That's a fun bit of history you get to care about forever now as a user!"