[nostrademons]

The vim formatters/syntax checkers I've used that actually try to parse the language - other than Lisp, which is the limiting case - are generally terrible. They all miss some corner case that makes them useless for daily work, since they generate too many false-positives on real code.

The ones I actually use all call out to the actual compiler - Python, Go, or Clang for C++.

Just because people write their own parsers doesn't make it a good idea. It may've been necessary when most compilers were proprietary and people didn't have an idea how to make a good API for a parser. But now - just don't do it. You'll save both you and your users a lot of pain.