Of course I can. If my tools are communicating with my compiler, they know <i>everything</i> it knows. I have a single tiny generic Emacs mode (and a similar Visual Studio extension) that handles <i>all</i> the languages designed on top of my extensibility framework.<p>It&#x27;s trivial. Any PEG parser I add on top automatically communicates all the highlighting, indentation data and all that to the tools (and it&#x27;s inferred from the declarative spec, no additional user input is required). Underlying typing engines do the same, for the nice tooltips and code completion. The very compiler core doest the same with all the symbol definitions, dependencies, etc. Easy.