pop_front implemented.

src/parser/list.rs

@@ -1,3 +1,4 @@
+use std::fmt::Debug;
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -19,7 +20,8 @@ pub struct Node<T> {
     parent: Option<Rc<Node<T>>>,
 }
 
-impl<T> List<T> {
+// TODO: This Debug is only needed because of the try_unwrap+expect
+impl<T: Debug> List<T> {
     pub fn new() -> Self {
         List { head: None }
     }
@@ -33,6 +35,22 @@ impl<T> List<T> {
         }
     }
 
+    pub fn pop_front(self) -> (Option<T>, List<T>) {
+        match self.head {
+            None => (None, List::new()),
+            Some(popped_node) => {
+                let extracted_node =
+                    Rc::try_unwrap(popped_node).expect("TODO I should handle this better");
+                (
+                    Some(extracted_node.data),
+                    List {
+                        head: extracted_node.parent,
+                    },
+                )
+            }
+        }
+    }
+
     pub fn without_front(&self) -> List<T> {
         List {
             head: self.head.as_ref().map(|node| node.parent.clone()).flatten(),