Alexander Markov
085e22dd72
Special sentinel values which are used for lazy initialization can be stored in variables of any type. In NNBD world Null is no longer a bottom type as null cannot be assigned into variables of non-nullable types. The new universal bottom type is Never, so type of sentinel values is changed from Null to Never. This also allows to make late fields non-nullable in the type propagation and avoid extra updates to field guards. This change also adds special handling of comparisons with sentinel values into constant propagation as it can constant fold comparisons of values with different cids. Fixes https://github.com/dart-lang/sdk/issues/40796 Change-Id: I8266cfba0cc434b78ffa9570c30d434d4380d4af Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/143864 Reviewed-by: Liam Appelbe <liama@google.com> Reviewed-by: Ryan Macnak <rmacnak@google.com> Commit-Queue: Alexander Markov <alexmarkov@google.com>
Dart
A client-optimized language for fast apps on any platform
Dart is:
-
Optimized for UI: Develop with a programming language specialized around the needs of user interface creation
-
Productive: Make changes iteratively: use hot reload to see the result instantly in your running app
-
Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web
Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:
-
Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.
-
Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).
License & patents
Dart is free and open source.
See LICENSE and PATENT_GRANT.
Using Dart
Visit the dart.dev to learn more about the language, tools, getting started, and more.
Browse pub.dev for more packages and libraries contributed by the community and the Dart team.
Building Dart
If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.
There are more documents on our wiki.
Contributing to Dart
The easiest way to contribute to Dart is to file issues.
You can also contribute patches, as described in Contributing.