Make the int-map lookup return 0 by default

script/types.go

@@ -42,10 +42,13 @@ func (m intMap) IndexGet(index tengo.Object) (tengo.Object, error) {
 	if !ok {
 		return nil, tengo.ErrInvalidIndexType
 	}
-	value, ok := m[indexStr.Value]
-	if !ok {
-		return tengo.UndefinedValue, nil
-	}
+
+	// value, ok := m[indexStr.Value]
+	// if !ok {
+	// 	return tengo.UndefinedValue, nil
+	// }
+
+	value := m[indexStr.Value]
 	return &tengo.Int{Value: value}, nil
 }