Kallen Tu
8bfb683892
This CL enables the primary constructors feature by default in Dart 3.13.
The primary constructors feature is a brevity feature. There are no new semantics, but it allows us to express declarations in a less verbose way.
This feature allows one constructor and a set of instance variables to be specified in the header of a declaration.
Currently a declaration with a constructor and some fields is written as:
```dart
// Current syntax.
class Point {
int x;
int y;
Point(this.x, this.y);
}
```
With a primary constructor, we would write the above as:
```
class Point(var int x, var int y);
```
If a primary constructor needs an initializer list or a body, they can be
specified inside the class using the `this` body syntax:
```dart
class Point(var int x, var int y) {
this : assert(x >= 0) {
print('Point created at $x, $y');
}
}
```
As part of this feature, you can also use the `new` and `factory` keywords to
declare constructors in the class body without repeating the class name:
```dart
class Point {
int x, y;
// Equivalent to Point(this.x, this.y)
new(this.x, this.y);
// Equivalent to Point.origin()
new origin() : x = 0, y = 0;
// Equivalent to factory Point.clone(Point other)
factory clone(Point other) => Point(other.x, other.y);
}
```
To learn more about the feature, check out the feature specification located here: https://github.com/dart-lang/language/blob/main/accepted/future-releases/primary-constructors/feature-specification.md
Tested: Has existing language, CFE, analyzer, analysis server tests.
Bug: https://github.com/dart-lang/sdk/issues/61524
Change-Id: I296f2fcd918b87bf2a1dd00256340759866c2423
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/489241
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Reviewed-by: Michael Thomsen <mit@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Kallen Tu <kallentu@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
131 lines
2.7 KiB
Dart
131 lines
2.7 KiB
Dart
// Copyright (c) 2011, 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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// Test that parameters keep their names in the output.
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import 'package:expect/async_helper.dart';
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import 'package:expect/expect.dart';
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import '../helpers/compiler_helper.dart';
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const String FOO = r"""
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void foo(a, b) {
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}
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""";
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const String BAR = r"""
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void bar(eval, $eval) {
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}
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""";
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const String PARAMETER_AND_TEMP = r"""
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void bar(t0, b) {
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{
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var t0 = 2;
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if (b) {
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bar(1, 2);
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t0 = 4;
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} else {
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t0 = 3;
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}
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print(t0);
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}
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print(t0);
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}
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""";
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const String NO_LOCAL = r"""
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foo(bar, baz) {
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if (bar) {
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baz = 2;
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} else {
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baz = 3;
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}
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return baz;
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}
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""";
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const String MULTIPLE_PHIS_ONE_LOCAL = r"""
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foo(param1, param2, param3) {
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var a = 2;
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if (param1) {
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if (param2) {
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if (param3) {
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a = 42;
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}
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print(a);
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}
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print(a);
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}
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print(a);
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}
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""";
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const String PARAMETER_INIT = r"""
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void foo(start, test) {
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var result = start;
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if (test) {
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foo(1, 2);
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result = 42;
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}
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print(result);
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}
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""";
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main() {
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runTests() async {
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await compile(
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FOO,
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entry: 'foo',
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check: (String generated) {
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Expect.isTrue(generated.contains(r"function(a, b) {"));
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},
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);
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await compile(
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BAR,
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entry: 'bar',
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check: (String generated) {
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Expect.isTrue(generated.contains(r"function($eval, $$eval) {"));
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},
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);
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await compile(
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PARAMETER_AND_TEMP,
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entry: 'bar',
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check: (String generated) {
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Expect.isTrue(generated.contains(r"print(t00)"));
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// Check that the second 't0' got another name.
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Expect.isTrue(generated.contains(r"print(t01)"));
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},
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);
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await compile(
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MULTIPLE_PHIS_ONE_LOCAL,
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entry: 'foo',
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check: (String generated) {
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Expect.isTrue(generated.contains(RegExp(r'var a(;| = 2;)')));
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// Check that there is only one var declaration.
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checkNumberOfMatches(RegExp("var").allMatches(generated).iterator, 1);
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},
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);
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await compile(
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NO_LOCAL,
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entry: 'foo',
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check: (String generated) {
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Expect.isFalse(generated.contains('var'));
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},
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);
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await compile(
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PARAMETER_INIT,
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entry: 'foo',
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check: (String generated) {
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// Check that there is only one var declaration.
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checkNumberOfMatches(RegExp("var").allMatches(generated).iterator, 1);
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},
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);
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}
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asyncTest(() async {
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print('--test from kernel------------------------------------------------');
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await runTests();
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});
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}
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