1 files changed, 3 insertions, 1 deletions
diff --git a/ast.h b/ast.h
index f8183f9..dac6e8a 100644
--- a/ast.h
+++ b/ast.h
@@ -28,7 +28,7 @@ struct atom {
 			struct repeat counts;
 			struct atom *child;
 		} repeat;
-		const struct atom *children[2];
+		struct atom *children[2];
 		const char *literal;
 	} u;
 };
@@ -38,6 +38,8 @@ void dump_atom(const struct atom *a);
 
 void print_regex(const struct atom *a);
 
+void simplify(struct atom *a);
+
 extern struct atom *ast;
 
 #endif