Trying to merge the TypeScript TextMate grammar and an updated CoffeeScript grammar seems like it would be an unspeakable nightmare. So it would be nice if the Civet parser / LSP could provide semantic tokens.

Essentially tokens that have {$loc} would be source tokens styled from the nearest ancestor that has some sort of {sematicToken} property. It might require passing a flag into the parser and skipping normal AST processing instead constructing a stream of semantic tokens.

https://code.visualstudio.com/api/references/vscode-api#DocumentSemanticTokensProvider (looks like it is very similar to how source maps work)