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>
This CL removes the unnecessary overrides of the `experiments` getter
from the tests and collects the corresponding experiment flags added to
the returned value of the getter in the individual tests to the
'experimentsForTests' list that is used by all tests. Specifically, the
experiments `variance` is enabled for all tests.
The flag `inference_update_1` is removed from the experiments list,
since it's enabled by default. In the tests that explicitly require a
distinction between the flag being enabled and disabled, the getter
`_isEnabled` is overridden and returns a value corresponding to the
test.
The flag `inference_update_4` still appears in one of the overrides of
the `experiments` getter, since enabling it in all tests appears
breaking.
This is a follow-up to
https://dart-review.googlesource.com/c/sdk/+/430720/comment/4c3f016e_4933f925/
Change-Id: I4d35e3c6259e2f7e6751d180b5790c13f68de1ba
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/434360
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Chloe Stefantsova <cstefantsova@google.com>
Kallen Tu