I am a strong believer that typed languages in general should have a compiler annotation mode that with configurable level of verbosity formats explicit types a

I am a strong believer that typed languages in general should have a compiler annotation mode that with configurable level of verbosity formats explicit types and structural info (dead code, exhaustive matching) into structured comments. This could maybe also be a pre-commit git hook transformation so that you could see how type changes propagate. The essential feature must be that the compiler overwrites them often and that they must be informative only.