Syntax highlighting is currently only based on the lexer and parse results.
Even then, we are not highlighting to the best of our knowledge, take:

In this context, we know that Tree a must both be types, but we are highlighting them as values.

Further, we should provide syntax highlighting based on the typecheck result of the AST which could allow us to provide more accurate highlighting in at least the following cases:

• selectors
• functions vs data constructors
• parameters
• assumes