diff --git a/compiler/erg_compiler/context.rs b/compiler/erg_compiler/context.rs
index 3813f685..ca8753b4 100644
--- a/compiler/erg_compiler/context.rs
+++ b/compiler/erg_compiler/context.rs
@@ -42,6 +42,21 @@ use Visibility::*;
 
 type Trait = Type;
 
+/// ```
+/// [Int, Str, Nat, Never, Obj, Str!, Module]
+/// => [], [Int, Str, Nat, Never, Obj, Str!, Module]
+/// => [[Int]], [Str, Nat, Never, Obj, Str!, Module]
+/// => [[Int], [Str]], [Nat, Never, Obj, Str!, Module]
+/// => ...
+/// => [[Int, Nat, Never, Obj]], [Str, Obj, Str!], [Module]]
+/// => [[Never, Nat, Int, Obj], [Str!, Str, Obj], [Module, Obj]]
+/// => [Never, Nat, Int, Obj, Str, Obj, Module, Obj]
+/// => [Never, Nat, Int, Str, Module, Obj]
+/// ```
+pub fn type_sort(_types: Vec<Type>) -> Vec<Type> {
+    todo!()
+}
+
 /// ```
 /// TyParamIdx::new(Add(R, O), O) => Nth(1)
 /// TyParamIdx::new(Add(R, F(O, I)), O) => Nested(Nth(1), 0)