add a note about undef values

2013-11-09 14:27:50 +09:00
parent 1126ec614f
commit 8a85e62472
1 changed files with 5 additions and 0 deletions
@@ -3,6 +3,11 @@

 typedef int pic_sym;

+/**
+ * `undef` values never seen from user-end: that is,
+ *  it's used only for repsenting internal special state
+ */
+
 enum pic_vtype {
  PIC_VTYPE_NIL = 1,
  PIC_VTYPE_TRUE,