Syntax highlighting in code frames and diffs

[MichaReiser]

We should consider highlighting code frames and diffs.

I think a good first step would be to implement semantic highlighting into ruff server that, given a string, emits a description of the highlighting. The codeframe and diff rendering can then reuse the same infrastructure to implement.

This is related to astral-sh/ruff-lsp#237

[Zander-1024]

This is really important. I hope this feature can be implemented soon.

[SnirShechter]

I'd very much like to see that.

Currently when using VSCode, you must use the Python extension for syntax highlighting so ruff can't completely replace it and they be used together (which kind-of misses the point of being fast when you must use another extension that's slow).

[danny-huang-openfind]

While this feature is also important to me, I believe a linter shouldn't be concerned with it. Ruff should focus on "making every kind of linter work within its scope," rather than "trying to solve everything."

[oramirite]

I think ruff's leap into automatic formatting - and doing a damn good job of it - kinda broke that seal already. I think the desire to see this feature stems from that. Completing the "triad" of core tools that would allow for ruff to be a complete replacement for the multiple plugins we currently need, would be a Godsend.

I'd very much enjoy having centralized configuration if these elements in ruff so I can fully replace the Intelligence stuff (it can be very slow).