anchor.diff:  	     (when (or (typep type 'v-t-type)
   		       (typep type 'v-spec-type))
   	       type)))
  +          ((and (listp spec) (eq (first spec) 'function))
  +           (make-instance
  +            'v-func-val :arg-types (mapcar #'type-spec->type (second spec))
  +            :return-types (mapcar #'type-spec->type
  +                                  (uiop:ensure-list (third spec)))))
             ((and (listp spec) (vtype-existsp (first spec)))
              (destructuring-bind (type dimensions) spec
                (make-instance 'v-array :element-type (if (keywordp type)
  
positive.code:   (if (and (v-element-type type) (v-dimensions type))
        (list (type->type-spec (v-element-type type)) (v-dimensions type))
        'v-array))
  
  (defun try-type-spec->type (spec &key (env *global-env*))
    (declare (ignore env))
  
negative.code: 			      :code-type :v-function)
  	     :initarg :flow-ids :reader flow-ids)))
  
  (def-v-type-class v-function (v-type)
    ((versions :initform nil :initarg :versions :accessor v-versions)
     (argument-spec :initform nil :initarg :arg-spec :accessor v-argument-spec)
     (glsl-string :initform "" :initarg :glsl-string :reader v-glsl-string)
     (glsl-name :initarg :glsl-name :accessor v-glsl-name)
     (return-spec :initform nil :initarg :return-spec :accessor v-return-spec)
     (v-place-index :initform nil :initarg :v-place-index :reader v-place-index)
     (multi-return-vars :initform nil :initarg :multi-return-vars
                        :reader multi-return-vars)
     (name :initform nil :initarg :name :reader name)
     (implicit-args :initform nil :initarg :implicit-args :reader implicit-args)
     (in-arg-flow-ids :initform (error 'flow-ids-mandatory :for :v-function
  				     :code-type :v-function)
  		    :initarg :in-arg-flow-ids :reader in-arg-flow-ids)
     (flow-ids :initform (error 'flow-ids-mandatory :for :v-function
  			      :code-type :v-function)
  	     :initarg :flow-ids :reader flow-ids)))
  
  (def-v-type-class v-user-function (v-function) ())
  
  (def-v-type-class v-stemcell (v-type) ())
  