Re:Ask HN: What are the most promising/interesting new progr...
by matt_o on Friday April 29, 2016 @05:16AM
(#11594561)
Elixir has _something_ similar: Behaviors - http://elixir-lang.org/getting-started/typespecs-and-behavio...
While this isn't exactly what you like, I thought I'd throw it out there because I find it a fair substitute, especially when paired with Dialyzer - a static code analysis tool: http://erlang.org/doc/man/dialyzer.html
(I'm assuming the comparisons to ruby mean that it is very loosely typed, but I could be wrong). I wouldn't want to build a highly distributed app without a bunch of compiler help.