Unify var-var

schala-lang/language/src/typechecking.rs

@@ -365,7 +365,9 @@ impl<'a> TypeContext<'a> {
       },
       (a @ Var(_), b @ Const(_)) => self.unify(b, a),
       (Var(v1), Var(v2)) => {
-        panic!()
+        self.unification_table.unify_var_var(v1.clone(), v2.clone())
+          .or_else(|_| TypeError::new(format!("Two type variables {:?} and {:?} couldn't unify", v1, v2)))?;
+        Ok(Var(v1.clone())) //arbitrary decision I think
       },
       (a, b) => TypeError::new(format!("{:?} and {:?} do not unify", a, b)),
     }