| // Copyright (c) 2022, 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. |
| |
| /// @assertion |
| /// primary ::= // Existing productions... |
| /// | switchExpression |
| /// |
| /// switchExpression ::= 'switch' '(' expression ')' '{' |
| /// switchExpressionCase ( ',' switchExpressionCase )* |
| /// ','? '}' |
| /// switchExpressionCase ::= guardedPattern '=>' expression |
| /// |
| /// The body is a series of cases. Each case has a pattern, optional guard, and |
| /// a single expression body. As with other expression forms containing a list |
| /// of subelements (argument lists, collection literals), the cases are |
| /// separated by commas with an optional trailing comma. Since the body of each |
| /// case is a single expression with a known terminator, it's easy to tell when |
| /// one case ends and the next begins. That lets us do away with the case |
| /// keyword. |
| /// |
| /// To keep the syntax small and light, we also disallow a default clause. |
| /// Instead, you can use a shorter _ wildcard pattern to catch any remaining |
| /// values. |
| /// |
| /// @description Check that it is not an error if a trailing comma is not |
| /// omitted |
| /// @author sgrekhov22@gmail.com |
| |
| import "../../Utils/expect.dart"; |
| |
| main () { |
| int i = 2; |
| var x = switch(i) { |
| 1 => "one", |
| 2 => "two", |
| _ => "any", |
| }; |
| Expect.equals("two", x); |
| } |
