Baixar Dart SDK 3.13.0 per a Windows

Released on: Unreleased
Language
Dart 3.13 adds primary constructors to the language. To use this feature, set your package's SDK constraint lower bound to 3.13 or greater (sdk: '^3.13.0').
Primary constructors
The primary constructors feature is a brevity feature. There are no new semantics, but it lets you express declarations in a less verbose way.
This feature lets you specify one constructor and a set of instance variables in the header of a declaration.
Currently, you write a declaration with a constructor and some fields as:
// Current syntax.
class Point {
int x;
int y;
Point(this.x, this.y);
}
Now you can write:
class Point(var int x, var int y);
If a primary constructor needs an initializer list, a body, or both, you can specify them inside the class using the this body syntax:
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:
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.
Other changes
- Breaking change: A minor change has been made to type promotion to avoid unsound behavior. See SDK issue #62889 for details.
Libraries
dart:async
- Added Future.pause as an alternative to Future.delayed with no callback.
dart:core
- Added List.unmodifiableOf with better typing than List.unmodifiable.
- Added Map.unmodifiableOf with better typing than Map.unmodifiable.
- Added two getters on int for efficient bit-counting: trailingZeroBitCount (ctz) and oneBitCount (popcount). On native platforms they operate on the full 64-bit two's-complement representation; on the web they operate on the least-significant 32 bits. For more details, see SDK issue #52673.
dart:io
- The cookie-date parser now uses the correct algorithm again. A change to the parsing made it only accept the formats that cookie dates should have, but the RFC specifies a very permissive algorithm for what should be accepted.
- Behavioral change: File access and modification timestamps (File.lastModified, FileStat, lastAccessed, lastModified, setLastAccessed, setLastModified) now preserve microsecond precision instead of truncating or rounding to millisecond accuracy. See SDK issue #42444.
- Breaking change: Added InterfaceAddress, a subtype of InternetAddress that exposes a prefixLength field and a broadcast getter for network interface addresses. NetworkInterface.addresses now returns List<InterfaceAddress> instead of List<InternetAddress>. Code that implements NetworkInterface and overrides addresses will need to update the return type. For more details, see SDK issue #63216.
- The InternetAddress.lookup function no longer accepts invalid IPv4 addresses that are traditionally accepted by inet_aton.
dart:isolate
- Added synchronous execution and event loop control APIs to Isolate: Isolate.runSync, Isolate.create, Isolate.shutdownSync, Isolate.pinToCurrentThread, Isolate.isPinnedToCurrentThread, Isolate.runEventLoopSync, Isolate.onEvent, and Isolate.handleEvent.
dart:js_interop
- JSFunction and JSExportedDartFunction are now generic. JSExportedDartFunction<T>.toDart now casts the original wrapped function to the type argument T. Calls to isA<JSExportedDartFunction<T>> now also check that the wrapped function is a T. Otherwise, this type argument is purely descriptive and intended for increased static type safety. Importantly, the runtime types of JSFunction and JSExportedDartFunction do not change. For more details, see SDK issue #54557.
- JSObject.getPrototypeOf is added.
Tools
Analyzer
- Added LSP support for Inline Values (textDocument/inlineValue), allowing IDEs and debuggers to render inline variable evaluations during active debugging sessions.
- Introduced custom LSP methods (dart/textDocument/getFlutterWidgetPreviews and dart/workspace/getFlutterWidgetPreviews) to serve Flutter Widget Preview metadata to editor clients.
- Introduced custom LSP method dart/connectToDtd enabling language server clients to pair the Analysis Server with the Dart Tooling Daemon (DTD).
- A no_raw_types lint rule is introduced, which replaces the strict-raw-types analysis option, offering a more consistent approach.
- A no_dynamic_casts lint rule is introduced, which replaces the strict-casts analysis option, offering a more consistent approach.
- The following lint rules have been determined to be low value, and are deprecated: avoid_private_typedef_functions, and one_member_abstracts. If there is desire to keep using these, they can be re-implemented with analyzer plugins.
Linter
- Added new lint rules:
- async_return_with_no_await: Warns on async functions returning a non-Future value without using await.
- empty_container_bodies: Highlights empty bodies in classes, enums, mixins, or extensions.
- initialize_in_field_declaration: Recommends initializing fields at their declaration site where applicable.
- unnecessary_const_in_enum_constructor: Flags redundant const keywords in enum constructors.
- unnecessary_primary_constructor_body: Flags unnecessary or empty bodies on primary constructors.
- unnecessary_type_name_in_constructor: Flags redundant explicit type names in constructor declarations.
- use_declaring_parameters: Encourages declaring parameters in primary constructors.
- Added experimental lint rule use_primary_constructors to encourage adopting primary constructor syntax when Dart 3.13 primary constructor feature is enabled.
Formatter
- Show the supported language versions when running dart format --version --verbose.
- Don't crash if an analysis_options.yaml file has an include that points to a non-existent or unreadable file (dart_style #1840).
The following minor style bug fixes are not language versioned and apply to all formatted code:
- Fix a bug in eager splitting optimization that in rare cases would lead to a collection or argument list splitting unnecessarily (dart_style #1809).
- Don't add a blank line before a comment at the end of a compilation unit or braced body (dart_style #1644).
- Format extension type representation clauses the same way primary constructor formal parameter lists are formatted.
- When trailing commas are preserved, don't insert a newline before the ; in an enum with members unless there actually is a trailing comma. (Fix by @Barbirosha.)
The following changes only apply when formatting code at language version 3.13 or higher:
- Write a trailing comma in split extension type representation clauses when formatting code at language version 3.13 or higher (dart_style #1845).
- Fix a bug in an eager splitting optimization that would led the formatter to prefer less desirable solutions (dart_style #1847).
- Prefer to split call chains for single-element targets (dart_style #1732).
- Allow block formatting parameter lists (dart_style #1693).
- Allow as, is, and is! expressions to be block formatted (dart_style #1542).
- Separate imports into sections (dart_style #1120).
- In if-case pieces, split the guard if the pattern block-splits (dart_style #1596).
- When no solution fits the page width, prefer solutions where the overflowing lines have trailing string literals or comments (dart_style #1802, dart_style #1803, dart_style #1837).
- Force blank lines around a mixin or extension type declaration if it doesn't have a ; body.
Pub
- Added dart pub workspace list command to list all packages in the workspace along with their directory paths, with support for JSON output via --json.
- Added dart pub check-resolution-up-to-date internal command for fast timestamp-based package resolution validation without contacting remote servers.
- Added dart pub cache preload command for installing packages into PUB_CACHE directly from .tar.gz archives.
Dart CLI
- Added support for cross-compilation to the dart build cli command via the --target-os and --target-arch flags.
- Both dart build and dart compile now support using locally-built target binaries from a local SDK build directory (identifiable by the presence of a build.ninja file), avoiding the need to download them from Google Cloud Storage.
Dart Runtime
- Built-in fallback root certificates used if the system certificates cannot be found are no longer included. The existing --root-certs-file and --root-certs-cache options to the standalone VM may be used to provide certificates if the system certificates cannot be found.
C Embedder API
- Breaking change: Updated Dart_FileModifiedCallback in runtime/include/dart_tools_api.h to pass int64_t since in microseconds since epoch (matching FileStat microsecond precision), updated from milliseconds.
- Added Dart_SetCurrentThreadOwnsIsolate and Dart_GetCurrentThreadOwnsIsolate functions in runtime/include/dart_api.h (and dart_api_dl.h), allowing custom embedders to bind and query isolate thread ownership.