From 935e7410fd53c6ca75d7b22372046253fca84194 Mon Sep 17 00:00:00 2001
From: ychenfo <ychenfo@connect.ust.hk>
Date: Thu, 26 Aug 2021 11:54:37 +0800
Subject: [PATCH] check type params in class generic base declaration

---
 nac3core/src/toplevel/mod.rs             | 25 ++++++++++++++++++++----
 nac3core/src/toplevel/type_annotation.rs | 17 +++++++++++++---
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/nac3core/src/toplevel/mod.rs b/nac3core/src/toplevel/mod.rs
index bb4ea3dbb..4d02635b6 100644
--- a/nac3core/src/toplevel/mod.rs
+++ b/nac3core/src/toplevel/mod.rs
@@ -466,13 +466,13 @@ impl TopLevelComposer {
         let temp_def_list = self.extract_def_list();
         for (class_def, class_ast) in self.definition_ast_list.iter_mut() {
             let mut class_def = class_def.write();
-            let (class_bases, class_ancestors, class_resolver, class_id) = {
-                if let TopLevelDef::Class { ancestors, resolver, object_id, .. } = class_def.deref_mut() {
+            let (class_bases, class_ancestors, class_resolver, class_id, class_type_vars) = {
+                if let TopLevelDef::Class { ancestors, resolver, object_id, type_vars, .. } = class_def.deref_mut() {
                     if let Some(ast::Located {
                         node: ast::StmtKind::ClassDef { bases, .. }, ..
                     }) = class_ast
                     {
-                        (bases, ancestors, resolver, *object_id)
+                        (bases, ancestors, resolver, *object_id, type_vars)
                     } else {
                         unreachable!("must be both class")
                     }
@@ -519,10 +519,27 @@ impl TopLevelComposer {
                     if all_base.contains(&class_id) {
                         return Err("cyclic base detected".into());
                     }
+
+                    // find the intersection between type vars occured in the base class type parameter
+                    // and the type vars occured in the class generic declaration
+                    let type_var_occured_in_base = get_type_var_contained_in_type_annotation(&base_ty);
+                    for type_ann in type_var_occured_in_base {
+                        if let TypeAnnotation::TypeVarKind(id, ty) = type_ann {
+                            for (ty_id, class_typvar_ty) in class_type_vars.iter() {
+                                if id == *ty_id {
+                                    // if they refer to the same top level defined type var, we unify them together
+                                    self.unifier.unify(ty, *class_typvar_ty)?;
+                                }
+                            }
+                        } else {
+                            unreachable!("must be type var annotation")
+                        }
+                    }
+
                     class_ancestors.push(base_ty);
                 } else {
                     return Err(
-                        "class base declaration can only be concretized custom class".into()
+                        "class base declaration can only be custom class".into()
                     );
                 }
             }
diff --git a/nac3core/src/toplevel/type_annotation.rs b/nac3core/src/toplevel/type_annotation.rs
index 7839437f8..429cc470b 100644
--- a/nac3core/src/toplevel/type_annotation.rs
+++ b/nac3core/src/toplevel/type_annotation.rs
@@ -38,7 +38,11 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
             x => {
                 if let Some(obj_id) = resolver.get_identifier_def(x) {
                     let def = top_level_defs[obj_id.0].read();
-                    if let TopLevelDef::Class { .. } = &*def {
+                    if let TopLevelDef::Class { type_vars, .. } = &*def {
+                        // also check param number here
+                        if !type_vars.is_empty() {
+                            return Err(format!("expect {} type variable parameter but got 0", type_vars.len()))
+                        }
                         Ok(TypeAnnotation::CustomClassKind {
                             id: obj_id,
                             params: vec![],
@@ -67,7 +71,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
             }
         },
 
-        // TODO: subscript or call?
+        // TODO: subscript or call for virtual?
         ast::ExprKind::Subscript { value, slice, .. }
             if { matches!(&value.node, ast::ExprKind::Name { id, .. } if id == "virtual") } =>
         {
@@ -93,7 +97,7 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                     .get_identifier_def(id)
                     .ok_or_else(|| "unknown class name".to_string())?;
                 let def = top_level_defs[obj_id.0].read();
-                if let TopLevelDef::Class { .. } = &*def {
+                if let TopLevelDef::Class { type_vars, .. } = &*def {
                     let param_type_infos = if let ast::ExprKind::Tuple { elts, .. } = &slice.node {
                         elts.iter()
                             .map(|v| {
@@ -115,6 +119,13 @@ pub fn parse_ast_to_type_annotation_kinds<T>(
                             slice,
                         )?]
                     };
+                    if type_vars.len() != param_type_infos.len() {
+                        return Err(format!(
+                            "expect {} type parameters but got {}",
+                            type_vars.len(),
+                            param_type_infos.len()
+                        ))
+                    }
                     // NOTE: allow type var in class generic application list
                     Ok(TypeAnnotation::CustomClassKind {
                         id: obj_id,