(define set!
(ruby_func " lambda { |arguments, interpreter| if interpreter.current_environment.find(arguments[0]).nil? raise 'Variable ' + arguments[0] + ' is undefined' end interpreter.current_environment.define(arguments[0], arguments[1]) } ")
)
(define set!
(ruby_func " lambda { |arguments, interpreter| if interpreter.current_environment.find(arguments[0]).nil? raise 'Variable ' + arguments[0] + ' is undefined' end interpreter.current_environment.define(arguments[0], arguments[1]) } ")
)