| // 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. |
| |
| /// @assertion Dynamic Semantics |
| /// The new dynamic semantics are a superset of the original behavior. To avoid |
| /// redundancy and handle nested uses, the semantics are expressed in terms of a |
| /// separate procedure below: |
| /// . . . |
| /// Maps |
| /// A map literal of the form [<K, V>{entry_1 ... entry_n}] is evaluated as |
| /// follows: |
| /// 1. Allocate a fresh instance [map] of a class that implements |
| /// [LinkedHashMap<K, V>]. |
| /// |
| /// 2. For each [element] in the map literal: |
| /// i. Evaluate [element] using the procedure below. |
| /// |
| /// 3. The result of the map literal expression is [map]. |
| /// . . . |
| /// To evaluate a collection [element]: |
| /// This procedure handles elements in both list and map literals because the |
| /// only difference is how a base expression element or entry element is handled. |
| /// The control flow parts are the same so are unified here. |
| /// . . . |
| /// 4. Else, if [element] is a C-style [for] element: |
| /// |
| /// i. Evaluate the initializer clause of the element, if there is one. |
| /// ii. Loop: |
| /// a. Evaluate the condition expression to a value [condition]. |
| /// If there is no condition expression, use [true]. |
| /// b. If the boolean conversion of [condition] is not [true], exit |
| /// the loop. |
| /// c. Evaluate the body element using this procedure in the scope of |
| /// the variable declared by the initializer clause if there is one. |
| /// d. If there is an increment clause, execute it. |
| /// . . . |
| /// @description Checks that if [element] of map literal is a C-style [for] |
| /// element, this element is evaluated using the specified procedure. Checks that |
| /// the initializer clause of the element does not exist. |
| /// @author ngl@unipro.ru |
| |
| import "../../Utils/expect.dart"; |
| |
| main() { |
| var map1exp = <int, num>{}; |
| var i = 0; |
| for (; i < 10; i += 3) { |
| if (i.isOdd) { |
| map1exp[i] = i + 1.5; |
| } else { |
| map1exp[i] = i + 1; |
| } |
| } |
| map1exp[i] = i; |
| Expect.isTrue(map1exp is Map<int, num>); |
| |
| i = 0; |
| var map1 = <int, num>{ |
| for (; i < 10; i += 3) if (i.isOdd) i: i + 1.5 else i: i + 1 |
| }; |
| // map1exp {0: 1, 3: 4.5, 6: 7, 9: 10.5, 12: 12} |
| map1[i] = i; |
| Expect.isTrue(map1 is Map<int, num>); |
| Expect.mapEquals(map1exp, map1); |
| } |