adding zephyr-im master branch

zwgc/stack.h

@@ -0,0 +1,65 @@
+/* This file is part of the Project Athena Zephyr Notification System.
+ * It is one of the source files comprising zwgc, the Zephyr WindowGram
+ * client.
+ *
+ *      Created by:     Marc Horowitz <marc@athena.mit.edu>
+ *
+ *      $Id$
+ *
+ *      Copyright (c) 1989 by the Massachusetts Institute of Technology.
+ *      For copying and distribution information, see the file
+ *      "mit-copyright.h".
+ */
+
+
+#include <zephyr/mit-copyright.h>
+
+/****************************************************************************/
+/*                                                                          */
+/*               A generic stack type based on linked lists:                */
+/*                                                                          */
+/****************************************************************************/
+
+#ifndef TYPE_T_stack_TYPE
+#define TYPE_T_stack_TYPE
+
+#ifndef  NULL
+#define  NULL 0
+#endif
+
+typedef struct _TYPE_T_stack {
+    struct _TYPE_T_stack *next;
+    TYPE_T data;
+} *TYPE_T_stack;
+
+#define  TYPE_T_stack_create()           ((struct _TYPE_T_stack *) NULL)
+
+#define  TYPE_T_stack_empty(stack)       (!(stack))
+
+#ifdef DEBUG
+#define  TYPE_T_stack_top(stack)         ((stack) ? (stack)->data :\
+					  (abort(),(stack)->data))
+#else
+#define  TYPE_T_stack_top(stack)         ((stack)->data)
+#endif
+
+#ifdef DEBUG
+#define  TYPE_T_stack_pop(stack)  { TYPE_T_stack old = (stack);\
+				    if (!old)\
+				      abort(); /*<<<>>>*/\
+				    (stack) = old->next;\
+				    free(old); }
+#else
+#define  TYPE_T_stack_pop(stack)  { TYPE_T_stack old = (stack);\
+				    (stack) = old->next;\
+				    free(old); }
+#endif
+
+#define  TYPE_T_stack_push(stack,object) \
+           { TYPE_T_stack new = (struct _TYPE_T_stack *)\
+	       malloc(sizeof (struct _TYPE_T_stack));\
+	     new->next = (stack);\
+	     new->data = object;\
+	     (stack) = new; }
+
+#endif