/* -*-c-*-
*
- * $Id: darray.h,v 1.5 2000/06/17 10:37:39 mdw Exp $
+ * $Id: darray.h,v 1.7 2004/04/08 01:36:11 mdw Exp $
*
* Dynamically growing dense arrays
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: darray.h,v $
- * Revision 1.5 2000/06/17 10:37:39 mdw
- * Add support for arena management.
- *
- * Revision 1.4 1999/12/10 23:42:04 mdw
- * Change header file guard names.
- *
- * Revision 1.3 1999/11/05 14:32:43 mdw
- * Minor change in argument naming.
- *
- * Revision 1.2 1999/10/29 22:59:22 mdw
- * New array adjustment macros for unsigned arguments.
- *
- * Revision 1.1 1999/10/22 22:37:26 mdw
- * New dynamic array implementation replaces `dynarray.h'.
- *
- */
-
#ifndef MLIB_DARRAY_H
#define MLIB_DARRAY_H
/*----- Stack-like operations ---------------------------------------------*/
+/* --- @DA_FIRST@ --- *
+ *
+ * Arguments: @a@ = pointer to an array block (multiply evaluated)
+ *
+ * Use: Evaluates to the initial element in array @a@. It is unsafe
+ * to do this if the array is empty. The array is not changed.
+ */
+
+#define DA_FIRST(a) (DA(a)[0])
+
+/* --- @DA_LAST@ --- *
+ *
+ * Arguments: @a@ = pointer to an array block (multiply evaluated)
+ *
+ * Use: Evaluates to the final element in array @a@. It is unsafe
+ * to do this if the array is empty. The array is not changed.
+ */
+
+#define DA_LAST(a) (DA(a)[(a)->b.len - 1])
+
/* --- @DA_PUSH@ --- *
*
* Arguments: @a@ = pointer to an array block (multiply evaluated)
*/
#define DA_SHIFT(a) \
- ((a)->b.len ? ((void)0) : THROW(DAEXC_UFLOW), \
+ ((a)->b.len ? ((void)0) : THROW(DAEXC_UFLOW), \
(a)->b.len--, \
(a)->b.sz--, \
(a)->b.off++, \