add initial reference invalidation

+ Makes vec example actually memory safe, which is cool

+ Specify owner > sub relationships with ">" in closure parameter
  lists, uses the same group idea as closure calls

+ Relies on users implementing functions in a consistent manner,
  since you can kind of do whatever with pointers. Presumably
  there would be a stdlib of vec/map/set etc. which applications
  could then use and by proxy be memory safe. Although some more
  checks wouldn't hurt, I suppose?

+ Not sure I like having reference invalidation be 'just a move',
  seems to work alright but the semantics of it are a bit muddy.

1 files changed, 10 insertions, 0 deletions

diff --git a/include/fwd/ast.h b/include/fwd/ast.h
index f550647..4359525 100644
--- a/include/fwd/ast.h
+++ b/include/fwd/ast.h
@@ -103,6 +103,15 @@ struct type {
 	/* next */
 	struct type *n;
 
+	/* used in parameter lists; this param owns the next one
+	 *
+	 * Is a pointer necessary here? A bool could work as well, as long as we're
+	 * just doing 'this owns the next element in this list', but if we
+	 * eventually support more complex relationships, like 'this owns these
+	 * next params and one of the next params owns at least one more' or
+	 * something along those lines, but that's an unsure TODO) */
+	struct type *or;
+
 	/* opt group */
 	long group;
 
@@ -727,5 +736,6 @@ static inline struct type *callable_types(struct type *t)
 }
 
 void opt_group(struct ast *a, struct ast *b);
+void own_type_group(struct type *owner, struct type *sub);
 
 #endif /* AST_H */