A bunch of languages are moving towards integrating IDE tools into the compiler with some kind of API. This allows for on-the-fly type checking, better syntax h

A bunch of languages are moving towards integrating IDE tools into the compiler with some kind of API. This allows for on-the-fly type checking, better syntax highlighting, better autocompletion, automatically generating bits of boilerplate, instantly testing a block of code, etc. For a language with a great example of this, check out Idris's IDE protocol: http://docs.idris-lang.org/en/latest/reference/ide-protocol.html http://docs.idris-lang.org/en/latest/reference/ide-protocol..... The way this works helps create an awesome feedback loop where the editor _is_ the REPL. Something like that would be a great addition to Rust and would definitely help improve the overall tooling for the language.