- Replace Bwd by ordinary list?
- Interface aliases should be allowed in adjustments, too
- Refactor Parser.hs into applicative style
- ItfMap should not be a syntactic element, so not attached with source code location etc.
- When defining interface Left = left: Int, there should be an error as there is already the definition Either (commands and constructors share the same namespace)
- Better error reporting for macros "include prelude" (print precise location)