Ruby has call/cc http://rubydoc.info/stdlib/core/1.9.3/Kernel:callcc http://rubydoc.info/stdlib/core/1.9.3/Kernel:callcc Thus you can implement pretty much an

Ruby has call/cc http://rubydoc.info/stdlib/core/1.9.3/Kernel:callcc http://rubydoc.info/stdlib/core/1.9.3/Kernel:callcc Thus you can implement pretty much anything you want in ruby, including COME FROM.