I’ve made a small proof of concept demo for the refactoring and code navigation extension I asked about last week.
The linting, navigation and renaming are all driven in a language-agnostic way by wiring together scope and identifier annotations on the syntax tree with some code snippets and document transforms. I’ve included a small demo grammar. The demo page explains how the features.
Some things are not quite right (e.g. language features are configured in the wrong place) and the functionality is a bit limited but I think it has potential.