diff --git a/src/routes/cours.rs b/src/routes/cours.rs
index ffa8e0d..1f72197 100644
--- a/src/routes/cours.rs
+++ b/src/routes/cours.rs
@@ -38,41 +38,33 @@ struct FileNode {
     children: Vec<FileNode>,
 }
 
-/// Build the filetree
 fn get_filetree(dir_path: &str, exclusion_list: Vec<String>) -> FileNode {
-    let entries = std::fs::read_dir(dir_path).unwrap();
+    let children = std::fs::read_dir(dir_path).unwrap()
+        .filter_map(Result::ok)
+        .filter_map(|entry| {
+            let entry_path = entry.path();
+            let entry_name = entry_path.file_name()?.to_str()?;
 
-    let mut children = Vec::new();
-    for entry in entries.filter_map(Result::ok) {
-        let entry_path = entry.path();
-        let entry_name = entry_path.file_name().and_then(|n| n.to_str()).unwrap();
+            // Exclude element with the exclusion_list
+            if exclusion_list.iter().any(|pattern| {
+                Regex::new(pattern)
+                    .map(|re| re.is_match(entry_name))
+                    .unwrap_or(false)
+            }) {
+                return None;
+            }
 
-        // We should support regex?
-        if !exclusion_list
-            .iter()
-            .any(|pattern| match Regex::new(pattern) {
-                Ok(re) => re.is_match(entry_name),
-                Err(e) => {
-                    eprintln!("{e}");
-                    false
-                }
-            })
-        {
-            let filename = entry_name.to_string();
             if entry_path.is_file() {
-                children.push(FileNode {
-                    name: filename,
+                Some(FileNode {
+                    name: entry_name.to_string(),
                     is_dir: false,
                     children: vec![],
-                });
+                })
             } else {
-                children.push(get_filetree(
-                    entry_path.to_str().unwrap(),
-                    exclusion_list.to_owned(),
-                ));
+                Some(get_filetree(entry_path.to_str().unwrap(), exclusion_list.clone()))
             }
-        }
-    }
+        })
+        .collect();
 
     FileNode {
         name: Path::new(dir_path)