;; elephant-tal.lisp 

;; Author: Clinton Ebadi <clinton@unknownlamer.org>
;; Author: Edward Marco Baringer <mb@bese.it>

;; Minor tal extension for persistent classes adapted from yaclml

(in-package :org.unknownlamer.golgonooza.elephant)

(defmethod yaclml:fetch-tal-value (name (obj persistent-object))
  (if (and (slot-exists-p obj name)
           (slot-boundp obj name))
      (values (slot-value obj name) t)
      (values nil nil)))

(defmethod (setf yaclml:fetch-tal-value) (value name (obj persistent-object))
  (if (slot-exists-p obj name)
      (setf (slot-value obj name) value)
      (error 'yaclml::unfound-tal-variable :variable-name value :environment obj)))

;; Copyright (c) 2002-2005, Edward Marco Baringer
;; Copyright (c) 2009, Clinton Ebadi
;; All rights reserved. 
;; 
;; Redistribution and use in source and binary forms, with or without
;; modification, are permitted provided that the following conditions are
;; met:
;; 
;;  - Redistributions of source code must retain the above copyright
;;    notice, this list of conditions and the following disclaimer.
;; 
;;  - Redistributions in binary form must reproduce the above copyright
;;    notice, this list of conditions and the following disclaimer in the
;;    documentation and/or other materials provided with the distribution.
;;
;;  - Neither the name of Edward Marco Baringer, nor BESE, nor the names
;;    of its contributors may be used to endorse or promote products
;;    derived from this software without specific prior written permission.
;; 
;; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
;; "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
;; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
;; A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
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;; LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.