anchor.diff:  ;; TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   ;; SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   
  -;; $Id: gtktree.lisp,v 1.25 2006-10-17 15:27:52 espen Exp $
  +;; $Id: gtktree.lisp,v 1.26 2007-01-07 19:56:05 espen Exp $
   
   
   (in-package "GTK")
  
positive.code:   (column int)
    (gvalue gvalue))
  
  (defgeneric tree-model-value (model row column))
  
  (defmethod tree-model-value ((model tree-model) row column)
    (let ((index (tree-model-column-index model column)))
      (with-gvalue (gvalue)
        (%tree-model-get-value model (ensure-tree-iter model row) index gvalue))))
  
  (defgeneric tree-model-row-data (model row))
  
  (defmethod tree-model-row-data ((model tree-model) row)
    (coerce
  
negative.code: (defmethod tree-model-column-name ((model tree-model) index)
    (svref (user-data model 'column-names) index))
  
  
  (defmethod (setf tree-model-row-data) ((data list) (model tree-model) (iter tree-iter))
    (loop
  