Implemented the backtracing logic for walking.

src/renderer/renderer.rs

@@ -210,16 +210,27 @@ fn walk_path_from_single_level<'a>(
 
 fn new_walk_path<'a>(
     breadcrumbs: Vec<&'a dyn ContextElement>,
-    path: &Vec<&str>,
+    path: &'a Vec<&str>,
 ) -> Result<&'a dyn ContextElement, RenderError<'a>> {
     for context in breadcrumbs.iter().rev() {
         match walk_path_from_single_level(*context, path)? {
+            // If no walking was done at all, keep looping
             WalkResult::NoWalk => {}
-            WalkResult::PartialWalk => {}
-            WalkResult::FullyWalked(_) => {}
+            // If we partially walked then stop trying to find
+            // anything
+            WalkResult::PartialWalk => {
+                return Err(RenderError::NotFound {
+                    path: path,
+                    breadcrumbs: breadcrumbs,
+                })
+            }
+            WalkResult::FullyWalked(new_context) => return Ok(new_context),
         }
     }
-    Err(RenderError::Generic("temp".to_owned()))
+    Err(RenderError::NotFound {
+        path: path,
+        breadcrumbs: breadcrumbs,
+    })
 }
 
 // TODO: rename walk_path_from_single_level