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This Week in Dart - Issue 14

Hello fellow Dartisans! Welcome to the fourteenth issue of This Week in Dart! This Week in Dart's aim is to be a useful collection of changes and news from across the Dart ecosystem and its surrounding community.

To contribute to this and future issues, feel free to contribute on GitHub or suggest content for next week on GitHub discussions.

To discuss this week's issue, feel free to join us on the Unofficial Dart Community Discord in the #this-week-in-dart channel.


While not new, we thought it would be worth calling out some experimental platform support that Dart has in progress and available in the beta and dev channels.

On those channels, versions 2.17.0-266 or later, you can now find experimental builds for RISC-V (RV64GC) on Linux.

Also on those channels, versions 2.18.0-66 or later, you can find experimental builds for ARM64 on Windows.

To download these builds, see the download links or instructions on the Dart SDK Archive.

If you experience any issues trying the latest experimental builds, make sure to report an issue to the Dart SDK with reproduction information.

Community updates



Learning materials

Project releases

Project updates

Dart SDK updates

35 unique authors have contributed 132 commits to the Dart SDK in the past week.

The following are some handpicked, interesting changes:

Keep in mind, none of these changes are guaranteed to eventually land in a stable release.

Language updates and discussion

This week saw a standalone specification for sealed types, separate from the larger [type modifiers specification][], which is a proposal for expanded capability modifiers for classes and mixins.

Sealed types are essential for exhaustiveness checking, a core part of support for patterns.

At a high level, marking a type sealed, prevents it from being directly constructed, and all subtypes must be defined in the same library. This allows all subtypes to be known, enabling exhaustiveness checking when matching on a value with the sealed type.

Records and other parts of patterns have also been seeing extensive implementation work across all parts of the SDK over the past month, and final touches around their language specifications alongside fixes and improvements have been made as well.

To learn more about and contribute to discussion of these and other potential changes to the Dart language, visit the Dart language repository.

Package of the week

The package of the week is the Dart build ecosystem, including packages such as package:build and package:build_runner.

The Dart build system provides a way of generating files using Dart code, where files are generated directly on disk and are incrementally built. It's used across the ecosystem in tools and libraries such as the underlying incremental Dart to JavaScript compilation used in package:webdev through package:build_web_compilers or for code generation in package:freezed and package:json_serializable.

The build system is flexible and extensible and even supports configuration through a build.yaml file and package:build_config. Consider using it for in your next code generation project, static site generator, or compilation tool.

To learn more about the Dart build system and how to use it, see package:build_runner and package:build on as well its docs on GitHub.

Dart's package ecosystem is growing fast, and we want to help foster that growth. If you know of any great open source projects, let us know by suggesting a package on GitHub discussions.

Upcoming events

Check the Flutter Meetup Network and the Dart Language tag on Meetup to find an event near you or online and connect with other Dart developers!

Let us know about other future events on the events discussion board.

Quotes and notes

Share quotes and comments you see and hear about Dart on our quotes discussion board for future inclusion!

Dart is an easy language to learn #dartlang

—@d0rich_dev on Twitter

Apologies to @override, @freezed, @experimental, @immutable and all the other innocent Twitter handles that we've tagged over the years by tweeting Dart code that contains annotations. Thank goodness the Dart language doesn't include an @elonmusk annotation!

—@timsneath on Twitter

Dart jobs

If you know of any jobs which use or are related to Dart, let us know in the Job postings for Dart discussion board, and we will be happy to include them here!