Cleanup.

src/parser/list.rs

@@ -26,7 +26,6 @@ impl<T> Node<T> {
     }
 }
 
-// TODO: This Debug is only needed because of the try_unwrap+expect
 impl<T> List<T> {
     pub fn new() -> Self {
         List { head: None }
@@ -47,7 +46,7 @@ impl<T> List<T> {
             Some(popped_node) => {
                 let extracted_node = match Rc::try_unwrap(popped_node) {
                     Ok(node) => node,
-                    Err(e) => panic!("try_unwrap failed on Rc in pop_front on List."),
+                    Err(_) => panic!("try_unwrap failed on Rc in pop_front on List."),
                 };
                 (
                     Some(extracted_node.data),