[eru]

ML family languages (like Haskell) had proper type inference for decades now. And yes, integrating that with your editor/IDE is a good idea.

Depending on what you want to do, you might also want to start with the types and have the computer figure out the implementation.

> It might even not show you types as code at all and by default and overlay/add this info only on request.

Types annotations are often are great documentation, and there's a lot of practical knowledge in the ML communities about what types annotations to show in the source for helping with understand and debugging and which ones to leave out as clutter.

I wrote 'proper type inference' above, because it's much more powerful than the watered down version Go and C++ give you. See eg https://news.ycombinator.com/item?id=8447280 for a Rust example.