diff --git a/sample/sample.cpp b/sample/sample.cpp
index 8ea1e04..703a772 100644
--- a/sample/sample.cpp
+++ b/sample/sample.cpp
@@ -14,8 +14,10 @@ int main() {
     std::sort(keys.begin(), keys.end());
     keys.erase(std::unique(keys.begin(), keys.end()), keys.end());
 
+    const char* index_filename = "tmp.idx";
+
+    // The trie index type
     using trie_type = xcdat::trie_8_type;
-    const std::string index_filename = "tmp.idx";
 
     // Build and save the trie index.
     {
@@ -26,33 +28,53 @@ int main() {
     // Load the trie index.
     const auto trie = xcdat::load<trie_type>(index_filename);
 
-    std::cout << "Basic operations" << std::endl;
+    // Lookup
     {
-        const auto id = trie.lookup("MacBook_Pro");
-        if (id.has_value()) {
-            std::cout << trie.decode(id.value()) << " -> " << id.has_value() << std::endl;
-        } else {
-            std::cout << "Not found" << std::endl;
-        }
+        const auto id = trie.lookup("Mac_Pro");
+        std::cout << "lookup(Mac_Pro) = " << id.value_or(UINT64_MAX) << std::endl;
+    }
+    {
+        const auto id = trie.lookup("Google_Pixel");
+        std::cout << "lookup(Google_Pixel) = " << id.value_or(UINT64_MAX) << std::endl;
     }
 
-    std::cout << "Common prefix search" << std::endl;
+    // Decoding
     {
+        const auto dec = trie.decode(4);
+        std::cout << "decode(4) = " << dec << std::endl;
+    }
+
+    // Common prefix search
+    {
+        std::cout << "common_prefix_search(MacBook_Air) = {" << std::endl;
         auto itr = trie.make_prefix_iterator("MacBook_Air");
         while (itr.next()) {
-            std::cout << itr.decoded_view() << " -> " << itr.id() << std::endl;
+            std::cout << "   (" << itr.decoded_view() << ", " << itr.id() << ")," << std::endl;
         }
+        std::cout << "}" << std::endl;
     }
 
-    std::cout << "Predictive search" << std::endl;
+    // Predictive search
     {
+        std::cout << "predictive_search(Mac) = {" << std::endl;
         auto itr = trie.make_predictive_iterator("Mac");
         while (itr.next()) {
-            std::cout << itr.decoded_view() << " -> " << itr.id() << std::endl;
+            std::cout << "   (" << itr.decoded_view() << ", " << itr.id() << ")," << std::endl;
         }
+        std::cout << "}" << std::endl;
     }
 
-    std::remove(index_filename.c_str());
+    // Enumerate all the keys in the trie (in lex order).
+    {
+        std::cout << "enumerate() = {" << std::endl;
+        auto itr = trie.make_enumerative_iterator();
+        while (itr.next()) {
+            std::cout << "   (" << itr.decoded_view() << ", " << itr.id() << ")," << std::endl;
+        }
+        std::cout << "}" << std::endl;
+    }
+
+    std::remove(index_filename);
 
     return 0;
 }