- Holds a DefID and a reference to the Project
- Pretty-prints def signatures
- Use handles when printing types (WIP)
Known issues:
- Printing recursive types recurses forever
- There's some unrelated name resolution stuff going on that needs investigating.
TODO:
- Better name
- HandleMut?
- More interfaces!
- Migrate everything to use handles when oop semantics are easiest
- Reject plain recursive types, and don't recurse through reference types when printing
