Try an enum.

Author: davidgiven

lang/pc/comp/node.xh

@@ -2,12 +2,15 @@
 #ifndef NODE_H_
 #define NODE_H_
 
+enum {
+    Value           = 0       /* constant */
+};
+    
 struct node {
     struct node *nd_left;
 #define nd_next nd_left
     struct node *nd_right;
     int nd_class;               /* kind of node */
-#define Value           0       /* constant */
 #define Name            1       /* an identifier */
 #define Uoper           2       /* unary operator */
 #define Boper           3       /* binary operator */