ruby-next/ruby-next: Ruby Next makes modern Ruby code run in older versions and alternative implementations

Ruby Next is a transpiler and a collection of polyfills for supporting the latest and upcoming Ruby features (APIs and syntax) in older versions and alternative implementations. For example, you can use pattern matching and Kernel#then in Ruby 2.5 or mruby. Who might be interested in Ruby Next? Ruby gems maintainers who want to write code using the latest Ruby version but still support older ones. Application developers who want to give new features a try without waiting for the final release (or, more often, for the first patch). Users of non-MRI implementations such as mruby, JRuby, TruffleRuby, Natalie, Opal, RubyMotion, Artichoke, Prism. Ruby syntax enthusiasts who want to experiment with custom syntax extensions 👩‍🔬👨‍🔬.