fix: filter expression return type.

kclvm/sema/src/resolver/node.rs

@@ -320,15 +320,15 @@ impl<'ctx> MutSelfTypedResultWalker<'ctx> for Resolver<'ctx> {
                 target_node.unwrap(),
                 key_name,
                 val_name,
-                iter_ty,
+                iter_ty.clone(),
                 quant_expr.target.get_pos(),
             );
             self.expr_or_any_type(&quant_expr.if_cond);
             let item_ty = self.expr(&quant_expr.test);
             self.leave_scope();
             match &quant_expr.op {
                 ast::QuantOperation::All | ast::QuantOperation::Any => self.bool_ty(),
-                ast::QuantOperation::Filter => item_ty,
+                ast::QuantOperation::Filter => iter_ty,
                 ast::QuantOperation::Map => Rc::new(Type::list(item_ty)),
             }
         }

test/grammar/quant/filter/simple_list_2/main.k

@@ -0,0 +1,25 @@
+schema Student:
+    name: str
+    id: int
+    grade: int
+
+    check:
+        id >= 0
+        0 <= grade <= 100
+
+students: [Student] = [
+    {name = "Alice", id = 1, grade = 85}
+    {name = "Bob", id = 2, grade = 70}
+    {name = "Charlie", id = 3, grade = 90}
+    {name = "David", id = 4, grade = 80}
+    {name = "Eve", id = 5, grade = 95}
+]
+
+query_student_where_name = lambda students: [Student], name: str -> Student {
+    (filter s in students {
+        s.name == name
+    })?[0]
+}
+
+alice: Student = query_student_where_name(students, name="Alice")
+bob: Student = query_student_where_name(students, name="Bob")

test/grammar/quant/filter/simple_list_2/stdout.golden

@@ -0,0 +1,24 @@
+students:
+- name: Alice
+  id: 1
+  grade: 85
+- name: Bob
+  id: 2
+  grade: 70
+- name: Charlie
+  id: 3
+  grade: 90
+- name: David
+  id: 4
+  grade: 80
+- name: Eve
+  id: 5
+  grade: 95
+alice:
+  name: Alice
+  id: 1
+  grade: 85
+bob:
+  name: Bob
+  id: 2
+  grade: 70