anchor.diff:    "Returns two values: the effective arguments and body for a function with
   the given lambda-list and body."
   
  -  ;; The lambda list is transformed as follows, since a javascript lambda list is just a 
  +  ;; The lambda list is transformed as follows, since a javascript lambda list is just a
     ;; list of variable names, and you have access to the arguments variable inside the function:
     ;; * standard variables are the mapped directly into the js-lambda list
     ;; * optional variables' variable names are mapped directly into the lambda list,
  
positive.code:          (init-form (if (listp spec) (second spec)))
           (supplied-p-var (if (listp spec) (third spec))))
      (values var init-form supplied-p-var)))
    
  (defun parse-aux-spec (spec)
    "Returns two values: variable and init-form"
    ;; [&aux {var | (var [init-form])}*])
  
negative.code:                              compiled-key)))
                 (cons key (compile-parenscript-form (ps-macroexpand val-expr)
                                                     :expecting :expression)))))))
  
  (define-ps-special-form instanceof (value type)
    `(js:instanceof ,(compile-parenscript-form value :expecting :expression)
                    ,(compile-parenscript-form type :expecting :expression)))
  