diff --git a/src/ast/mod.rs b/src/ast/mod.rs
index 6adff90..3386c9c 100644
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@@ -1,5 +1,47 @@
 pub mod node {
     include!(concat!(env!("OUT_DIR"), "/src/ast/node.rs"));
+    
+    impl Default for Parameters {
+        fn default() -> Self {
+            Self::new(vec![])
+        }    
+    }
+    
+    impl Default for GenericParameters {
+        fn default() -> Self {
+            Self::new(Box::new(IdentifierList::new(vec![])))
+        }
+    }
+    
+    impl Default for GenericArguments {
+        fn default() -> Self {
+            Self::new(Box::new(TypeUseList::new(vec![])))
+        }
+    }
+    
+    impl Default for ImplementsList {
+        fn default() -> Self {
+            Self::new(vec![])
+        }
+    }
+    
+    impl ReturnType {
+        pub fn void() -> Self {
+            Self::new(Box::new(TypeUse::PrimitiveType(PrimitiveType::Void)))
+        }
+    }
+    
+    impl Default for ClassConstructor {
+        fn default() -> Self {
+            Self::new(vec![])
+        }
+    }
+    
+    impl Default for ClosureParameters {
+        fn default() -> Self {
+            Self::new(vec![])
+        }
+    }
 }
 
 pub mod build {