refactor Router::merge

src/router.rs

@@ -136,7 +136,11 @@ impl<T> Router<T> {
     }
 
     /// Merge a given router into current one.
+    ///
     /// Returns a list of [`InsertError`] for every failed insertion.
+    /// Note that this can result in a partially successful merge if
+    /// a subset of routes conflict.
+    ///
     /// # Examples
     ///
     /// ```rust
@@ -154,13 +158,13 @@ impl<T> Router<T> {
     /// # }
     /// ```
     pub fn merge(&mut self, other: Self) -> Result<(), MergeError> {
-        let mut errors = vec![];
+        let mut errors = Vec::new();
         other.root.for_each(|path, value| {
             if let Err(err) = self.insert(path, value) {
                 errors.push(err);
             }
-            true
         });
+
         if errors.is_empty() {
             Ok(())
         } else {

src/tree.rs

@@ -664,16 +664,19 @@ impl<T> Node<T> {
 impl<T> Node<T> {
     /// Iterates over the tree and calls the given visitor function
     /// with fully resolved path and its value.
-    pub fn for_each<V: FnMut(String, T) -> bool>(self, mut visitor: V) {
+    pub fn for_each<V: FnMut(String, T)>(self, mut visitor: V) {
         let mut queue = VecDeque::from([(self.prefix.clone(), self)]);
+
+        // Perform a BFS on the routing tree.
         while let Some((mut prefix, mut node)) = queue.pop_front() {
             denormalize_params(&mut prefix, &node.remapping);
+
             if let Some(value) = node.value.take() {
                 let path = String::from_utf8(prefix.unescaped().to_vec()).unwrap();
-                if !visitor(path, value.into_inner()) {
-                    return;
-                }
+                visitor(path, value.into_inner());
             }
+
+            // Traverse the child nodes.
             for child in node.children {
                 let mut prefix = prefix.clone();
                 prefix.append(&child.prefix);