gistfile1.txt

module Opal
  module Nodes
    module SexpNode
      def self.from_sexp(*)    # Imagine the extend(ClassMethods) dance.
      end
    end
  end
end

class Opal::Nodes::BaseNode
  include SexpNode
end

# Goal:

node = s(:args, ...)
node.class               # => Opal::Compiler::ArgsNode
node.is_a?(Sexp)         # => true
node.kwrest?             # Can have ArgsNode-specific methods
node.children            # But still is a Sexp
node.to_s                # (:args ...)