Rename list to context tree.

src/parser/nom_context.rs

@@ -15,22 +15,22 @@ struct Node<'r, T> {
     next: Link<'r, T>,
 }
 
-pub struct List<'r, T> {
+pub struct ContextTree<'r, T> {
     head: Option<Node<'r, T>>,
 }
 
-impl<'r, T> List<'r, T> {
+impl<'r, T> ContextTree<'r, T> {
     pub fn new() -> Self {
-        List { head: None }
+        ContextTree { head: None }
     }
 
-    pub fn with_additional_node(&'r self, element: T) -> List<'r, T> {
+    pub fn with_additional_node(&'r self, element: T) -> ContextTree<'r, T> {
         let new_node = Node {
             elem: element,
             next: self.head.as_ref(),
         };
 
-        List {
+        ContextTree {
             head: Some(new_node),
         }
     }