How do I do parent? Maybe Rc Instead of Box.

src/parser/nom_context.rs

@@ -7,6 +7,45 @@ use nom::error::VerboseError;
 use nom::IResult;
 use nom::Parser;
 
+pub struct TestContext<T> {
+    head: ContextReference<T>,
+}
+
+type ContextReference<T> = Option<Box<ContextLayer<T>>>;
+
+struct ContextLayer<T> {
+    data: T,
+    parent: ContextReference<T>,
+}
+
+struct ContextData {
+    fail_matcher: ChainBehavior,
+}
+
+impl TestContext<ContextData> {
+    pub fn new() -> Self {
+        TestContext { head: None }
+    }
+
+    pub fn with_additional_fail_matcher(
+        &self,
+        new_matcher: MatcherRef,
+    ) -> TestContext<ContextData> {
+        TestContext {
+            head: Some(Box::new(ContextLayer {
+                data: ContextData {
+                    fail_matcher: ChainBehavior::AndParent(Some(new_matcher)),
+                },
+                parent: self.head, // TODO FIX THIS
+            })),
+        }
+    }
+}
+
+/////
+///// OLD
+/////
+
 type MatcherRef = Rc<RefCell<dyn FnMut(&str) -> IResult<&str, &str, VerboseError<&str>>>>;
 
 struct FailChecker<'r>(&'r NomContext<'r>);