To expand on this a little, here is a thing that you can't translate to most programming languages. By defining a simple, pattern-based macro we can get much closer to the Dart version:

   (func: hello() => (displayln "Hello world"))
   (hello)

All you need to do this - to change the language syntax to look like that - is to write this:

    (define-syntax func:
      (syntax-rules (=>)
         [(_ name (formal ...) => expr ...)
          (define name (lambda (formal ...) expr ...))]))