anchor.diff: -;;;;; tré – Copyright (c) 2005–2009,2011–2012 Sven Michael Klose <pixel@copei.de>
  +;;;;; tré – Copyright (c) 2005–2009,2011–2013 Sven Michael Klose <pixel@copei.de>
   
   (defun %struct-option-keyword (e)
     (in? e :constructor))
  
positive.code:          (= (aref arr ,index) val)))))
  
  (defun %struct-getters (name fields)
    (let index 0
      (mapcar [%struct-single-get name (%struct-field-name _) (1+! index)] fields)))
  
  (defun %struct? (name)
    (let sym (%struct?-symbol name)
      `(defun ,sym (arr)
         (& (array? arr)
            (eq ',name (aref arr 0))))))
  
  (defun %struct-sort-fields (fields-and-options)
    (with-queue (fields options)
  
negative.code: 				   fields)))
  
  (defun %struct-make-init (fields g)
    (let index 1
      (mapcar [let argname (%struct-field-name _)
                `(= (aref ,g ,(1+! index))
                    (? (eq ,argname ',argname)
                       ,(& (cons? _)
                           (cadr _))
                       ,argname))}
              fields)))
  
  (defun %struct-make (name fields options)
    (with (sym (%struct-make-symbol name options)
  		 g (gensym)
           user-init (%struct-make-init fields g)
  	     type-init `((= (aref ,g 0) 'struct
                          (aref ,g 1) ',name)))
      `(defun ,sym ,(%struct-make-args fields)
         (let ,g (make-array ,(+ 2 (length fields)))
           ,@(? user-init
  	          (nconc type-init user-init)
  	          type-init)
  