Ruby plot twist.

main.rb

require 'ripper'
c = <<-S
def hello_world
  puts "hello world"
end
S
r = "#{Ripper.sexp(c)}"
puts "#{r.gsub(",", " ").gsub("[", "(").gsub("]", ")")}"

# output
# (:program
#  ((:def (:@ident  "hello_world" (1  4)) (:params  nil  nil  nil  nil  nil  nil  nil) 
#         (:bodystmt
#          ((:command (:@ident "puts" (2  2)) 
#                     (:args_add_block
#                      ((:string_literal (:string_content
#                                         (:@tstring_content "hello world" (2  8)))))
#                      false)))
#          nil  nil  nil))))

# INB4: 
# > Ruby is as much like Lisp as Javascript is, and I'd never call Javascript Lisp-like.
# Actually, it goes much deeper than that. The core AST for ruby uses car and cdr: 
# https://github.com/mruby/mruby/blob/master/include/mruby/compile.h#L49
# Also, Ruby was originally called MatzLisp: http://web.archive.org/web/20170526172735/http://matzlisp.org/

# PS:
# And the creator of the language uses Emacs (he was inspired by it to create Ruby in fact):
# https://www.slideshare.net/yukihiro_matz/how-emacs-changed-my-life
# https://github.com/ruby/elisp/blob/master/ruby-mode.el#L7
# http://web.archive.org/web/20170526172735/http://matzlisp.org/