|  | // Copyright (c) 2012, 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 | 
|  |  | 
|  | import "package:expect/expect.dart"; | 
|  |  | 
|  | main() { | 
|  | final f0 = 42; | 
|  | final f1; //# 01: compile-time error | 
|  | final int f2 = 87; | 
|  | final int f3; //# 02: compile-time error | 
|  | Expect.equals(42, f0); | 
|  | Expect.equals(87, f2); | 
|  |  | 
|  | Expect.equals(42, F0); | 
|  | Expect.equals(null, F1); //# 03: continued | 
|  | Expect.equals(87, F2); | 
|  | Expect.equals(null, F3); //# 04: continued | 
|  |  | 
|  | Expect.isTrue(P0 is Point); | 
|  | Expect.isTrue(P1 is int); | 
|  | Expect.isTrue(P2 is Point); | 
|  | Expect.isTrue(P3 is int); | 
|  |  | 
|  | Expect.isTrue(A0 is int); | 
|  | Expect.isTrue(A1 is int); | 
|  | Expect.isTrue(A2 is int); //# 08: runtime error | 
|  | Expect.isTrue(A3 is int); //# 08: continued | 
|  |  | 
|  | Expect.isTrue(C0.X is C1); | 
|  | Expect.isTrue(C0.X.x is C1); //# 09: compile-time error | 
|  |  | 
|  | Expect.equals("Hello 42", B2); | 
|  | Expect.equals("42Hello", B3); //# 10: compile-time error | 
|  | } | 
|  |  | 
|  | final F0 = 42; | 
|  | final F1; //                //# 03: syntax error | 
|  | final int F2 = 87; | 
|  | final int F3; //            //# 04: syntax error | 
|  |  | 
|  | class Point { | 
|  | final x, y; | 
|  | const Point(this.x, this.y); | 
|  | operator +(int other) => x; | 
|  | } | 
|  |  | 
|  | // Check that compile time expressions can include invocations of | 
|  | // user-defined final constructors. | 
|  | final P0 = const Point(0, 0); | 
|  | final P1 = const Point(0, 0) + 1; | 
|  | final P2 = new Point(0, 0); | 
|  | final P3 = new Point(0, 0) + 1; | 
|  |  | 
|  | // Check that we cannot have cyclic references in compile time | 
|  | // expressions. | 
|  | final A0 = 42; | 
|  | final A1 = A0 + 1; | 
|  | final dynamic A2 = A3 + 1; //# 08: continued | 
|  | final dynamic A3 = A2 + 1; //# 08: continued | 
|  |  | 
|  | class C0 { | 
|  | static final X = const C1(); | 
|  | } | 
|  |  | 
|  | class C1 { | 
|  | const C1() | 
|  | : x = C0.X //# 09: continued | 
|  | ; | 
|  | final x = null; | 
|  | } | 
|  |  | 
|  | // Check that sub-expressions of binary + are numeric. | 
|  | final B0 = 42; | 
|  | final B1 = "Hello"; | 
|  | final B2 = "$B1 $B0"; | 
|  | final B3 = B0 + B1; //# 10: continued |