mirror of
https://github.com/dart-lang/sdk
synced 2024-09-16 03:56:57 +00:00
07b9df22ac
No behavioral changes, just getting rid of a lot of redundant closures and helper functions. Change-Id: I55c52c2cc9e5505bb64203c31aad8d76847f8eeb Reviewed-on: https://dart-review.googlesource.com/14320 Commit-Queue: Bob Nystrom <rnystrom@google.com> Reviewed-by: William Hesse <whesse@google.com>
52 lines
1.7 KiB
Dart
52 lines
1.7 KiB
Dart
// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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// Evaluation of an if-null expression e of the form e1 ?? e2 is equivalent to
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// the evaluation of the expression ((x) => x == null ? e2 : x)(e1). The
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// static type of e is the least upper bound of the static type of e1 and the
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// static type of e2.
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import "package:expect/expect.dart";
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class A {
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final String a;
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A(this.a);
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}
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class B extends A {
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B(String v)
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: b = v,
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super(v);
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final String b;
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}
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class C extends A {
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C(String v)
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: c = v,
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super(v);
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final String c;
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}
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B nullB() => null;
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C nullC() => null;
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main() {
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Expect.equals(1, 1 ?? 2);
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Expect.equals(1, 1 ?? null);
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Expect.equals(2, null ?? 2);
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Expect.equals(null, null ?? null);
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Expect.equals('B', (new B('B') ?? new C('C')).a);
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Expect.equals('B', ((new B('B') ?? new C('C')) as dynamic).b);
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Expect.throwsNoSuchMethodError(() => ((new B('B') ?? new C('C')) as dynamic).c);
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Expect.equals('B', (new B('B') ?? nullC()).a);
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Expect.equals('B', ((new B('B') ?? nullC()) as dynamic).b);
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Expect.throwsNoSuchMethodError(() => ((new B('B') ?? nullC()) as dynamic).c);
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Expect.equals('C', (nullB() ?? new C('C')).a);
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Expect.throwsNoSuchMethodError(() => ((nullB() ?? new C('C')) as dynamic).b);
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Expect.equals('C', ((nullB() ?? new C('C')) as dynamic).c);
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Expect.throwsNoSuchMethodError(() => (nullB() ?? nullC()).a);
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Expect.throwsNoSuchMethodError(() => ((nullB() ?? nullC()) as dynamic).b);
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Expect.throwsNoSuchMethodError(() => ((nullB() ?? nullC()) as dynamic).c);
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}
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