For Ruby + Sorbet, it looks like Sorbet fits into Ruby syntax so we can reuse the same grammar, but you'd probably want the signatures to be considered as part of the methods. Working with the example from their website:

  sig {params(name: String).returns(Integer)}
  def main(name)
    puts "Hello, #{name}!"
    name.length
  end

I think the idea is that Asqi should treat `sig {}` sort of like a comment: prefix metadata attached to `def main`, rather than as an unrelated imperative call (whereas `attr_reader` would not have this behavior). Do you know whether Sorbet continues to work if you alias `sig` and any of its other definitions? For example, can I do this?

  def mysig(&proc)
    sig(&proc)  # or some other transformation
  end

  mysig {params(name: String).returns(Integer)}  # does this work? I hope/assume not
  def foo(name)
    name.length
  end

If the above is disallowed, then it should be easy to implement Ruby with Sorbet support built in. Otherwise I can probably do Ruby by itself, but it would be unaware of annotations attached to methods since to my knowledge there's normally no structural connection between statements that precede definitions.