/* -*-c-*-
*
- * $Id: darray.h,v 1.5 2000/06/17 10:37:39 mdw Exp $
+ * $Id: darray.h,v 1.6 2001/03/03 12:20:23 mdw Exp $
*
* Dynamically growing dense arrays
*
/*----- Revision history --------------------------------------------------*
*
* $Log: darray.h,v $
+ * Revision 1.6 2001/03/03 12:20:23 mdw
+ * New macros @DA_FIRST@ and @DA_LAST@ for stack/queue peeking.
+ *
* Revision 1.5 2000/06/17 10:37:39 mdw
* Add support for arena management.
*
/*----- 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++, \