anchor.diff:     :beginning-of-array #'init-vector-accumulator
      :array-element #'vector-accumulator-add
      :end-of-array #'vector-accumulator-get-sequence
  +   :array-type 'vector
      :beginning-of-object #'init-accumulator-and-prototype
      :object-key #'accumulator-add-key-or-set-prototype
      :object-value #'accumulator-add-value-or-set-prototype
  
positive.code: 
  ;;; The list semantics
  
  (defvar *json-array-type* 'vector
    "The Lisp sequence type to which JSON arrays are to be coerced.")
  
  (defun parse-number (token)
    "Take a number token and convert it to a numeric value."
    ;; We can be reasonably sure that nothing but well-formed (both in
  
negative.code:     "Designator for a function of no arguments (called at encountering
  a closing bracket for an array).")
  
  (define-custom-var (:array-type *json-array-type*) 'vector
    "The Lisp sequence type to which JSON arrays are to be coerced.")
  
  (define-custom-var (:beginning-of-object *beginning-of-object-handler*)
      (constantly t)
    "Designator for a function of no arguments (called at encountering
  