diff --git a/schala-lang/language/src/lib.rs b/schala-lang/language/src/lib.rs
index 8afe164..5bd39b4 100644
--- a/schala-lang/language/src/lib.rs
+++ b/schala-lang/language/src/lib.rs
@@ -34,6 +34,7 @@ mod symbol_table;
 mod builtin;
 mod reduced_ast;
 mod eval;
+mod visitor;
 
 mod schala;
 
diff --git a/schala-lang/language/src/visitor.rs b/schala-lang/language/src/visitor.rs
new file mode 100644
index 0000000..6fc14c0
--- /dev/null
+++ b/schala-lang/language/src/visitor.rs
@@ -0,0 +1,7 @@
+use std::error::Error;
+
+pub type VResult<T> = Result<T, Box<dyn Error>>;
+
+pub trait Visitor {
+
+}