| // Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| // @dart = 2.9 |
| |
| /// @assertion We extend the list grammar to allow spread elements in addition to |
| /// regular elements: |
| /// listLiteral: |
| /// const? typeArguments? '[' spreadableList? ']' |
| /// ; |
| /// |
| /// spreadableList: |
| /// spreadableExpression ( ',' spreadableExpression )* ','? |
| /// ; |
| /// |
| /// spreadableExpression: |
| /// expression | |
| /// spread |
| /// ; |
| /// |
| /// spread: |
| /// ( '...' | '...?' ) expression |
| /// ; |
| /// |
| /// Instead of [expressionList], this uses a new [spreadableList] rule since |
| /// [expressionList] is used elsewhere in the grammar where spreads aren't |
| /// allowed. Each element in a list is either a normal expression or a spread |
| /// element. If the spread element starts with [...?], it's a null-aware spread |
| /// element. |
| /// @description Checks spread element syntax |
| /// @author iarkh@unipro.ru |
| |
| |
| main() { |
| Map m1 = {...{?m1}}; //# 01: syntax error |
| } |