nac3core: fix polymorphic class method partial instantiation

nac3core/src/codegen/concrete_type.rs

@@ -147,8 +147,14 @@ impl ConcreteTypeStore {
                     fields: fields
                         .borrow()
                         .iter()
-                        .map(|(name, ty)| {
+                        .filter_map(|(name, ty)| {
-                            (*name, (self.from_unifier_type(unifier, primitives, ty.0, cache), ty.1))
+                            // filter out functions as they can have type vars and
+                            // will not affect codegen
+                            if let TypeEnum::TFunc( .. ) = &*unifier.get_ty(ty.0) {
+                                None
+                            } else {
+                                Some((*name, (self.from_unifier_type(unifier, primitives, ty.0, cache), ty.1)))
+                            }
                         })
                         .collect(),
                     params: params

nac3core/src/toplevel/composer.rs

@@ -1654,7 +1654,7 @@ impl TopLevelComposer {
                 if let TypeEnum::TFunc(func_sig) = self.unifier.get_ty(*signature).as_ref() {
                     let FunSignature { args, ret, vars } = &*func_sig.borrow();
                     // None if is not class method
-                    let self_type = {
+                    let uninst_self_type = {
                         if let Some(class_id) = self.method_class.get(&DefinitionId(id)) {
                             let class_def = self.definition_ast_list.get(class_id.0).unwrap();
                             let class_def = class_def.0.read();
@@ -1666,7 +1666,7 @@ impl TopLevelComposer {
                                     &self.primitives_ty,
                                     &ty_ann,
                                 )?;
-                                Some(self_ty)
+                                Some((self_ty, type_vars.clone()))
                             } else {
                                 unreachable!("must be class def")
                             }
@@ -1717,9 +1717,34 @@ impl TopLevelComposer {
                         };
                         let self_type = {
                             let unifier = &mut self.unifier;
-                            self_type.map(|x| unifier.subst(x, &subst).unwrap_or(x))
+                            uninst_self_type
+                                .clone()
+                                .map(|(self_type, type_vars)| {
+                                    let subst_for_self = {
+                                        let class_ty_var_ids = type_vars
+                                            .iter()
+                                            .map(|x| {
+                                                if let TypeEnum::TVar { id, .. } = &*unifier.get_ty(*x) {
+                                                    *id
+                                                } else {
+                                                    unreachable!("must be type var here");
+                                                }
+                                            })
+                                            .collect::<HashSet<_>>();
+                                        subst
+                                            .iter()
+                                            .filter_map(|(ty_var_id, ty_var_target)| {
+                                                if class_ty_var_ids.contains(ty_var_id) {
+                                                    Some((*ty_var_id, *ty_var_target))
+                                                } else {
+                                                    None
+                                                }
+                                            })
+                                            .collect::<HashMap<_, _>>()
+                                    };
+                                    unifier.subst(self_type, &subst_for_self).unwrap_or(self_type)
+                                })
                         };
-
                         let mut identifiers = {
                             // NOTE: none and function args?
                             let mut result: HashSet<_> = HashSet::new();

nac3core/src/toplevel/type_annotation.rs

@@ -280,9 +280,11 @@ pub fn get_type_from_type_annotation_kinds(
                             {
                                 let ok: bool = {
                                     // create a temp type var and unify to check compatibility
-                                    let temp =
+                                    p == *tvar || {
-                                        unifier.get_fresh_var_with_range(range.borrow().as_slice());
+                                        let temp =
-                                    unifier.unify(temp.0, p).is_ok()
+                                            unifier.get_fresh_var_with_range(range.borrow().as_slice());
+                                        unifier.unify(temp.0, p).is_ok()
+                                    }
                                 };
                                 if ok {
                                     result.insert(*id, p);

nac3core/src/typecheck/typedef/mod.rs

@@ -719,22 +719,18 @@ impl Unifier {
     /// Returns Some(T) where T is the instantiated type.
     /// Returns None if the function is already instantiated.
     fn instantiate_fun(&mut self, ty: Type, fun: &FunSignature) -> Type {
-        let mut instantiated = false;
+        let mut instantiated = true;
         let mut vars = Vec::new();
         for (k, v) in fun.vars.iter() {
             if let TypeEnum::TVar { id, range, .. } =
                 self.unification_table.probe_value(*v).as_ref()
             {
-                if k != id {
+                // need to do this for partial instantiated function
-                    instantiated = true;
+                // (in class methods that contains type vars not in class)
-                    break;
+                if k == id {
+                    instantiated = false;
+                    vars.push((*k, range.clone()));
                 }
-                // actually, if the first check succeeded, the function should be uninstatiated.
-                // The cloned values must be used and would not be wasted.
-                vars.push((*k, range.clone()));
-            } else {
-                instantiated = true;
-                break;
             }
         }
         if instantiated {