![]() I previously thought that the only possible situation where a switch statement over a valid type could be exhaustive without containing any cases was if the scrutinee type was the empty record type (`()`). But that isn't true at all: - The empty record type is inhabited by empty record objects, so such a switch statement would not be exhaustive after all. - It is possible for the user to create a type that can be exhaustively switched over with zero cases: by creating an abstract sealed class without any subclasses. In the latter case, I think it makes the most sense to treat the code after the switch as unreachable, because that's the normal behaviour of a switch over an exhaustive type with no `break`s. It is sound to do so because the type is uninhabited, therefore the body of the switch statement itself will never be reached. Bug: https://github.com/dart-lang/sdk/issues/50419 Change-Id: Ibc0a21226f25ae155db994343874354d5b8e4f7d Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/274621 Reviewed-by: Johnni Winther <johnniwinther@google.com> Commit-Queue: Paul Berry <paulberry@google.com> |
||
---|---|---|
.dart_tool | ||
.github | ||
benchmarks | ||
build | ||
docs | ||
pkg | ||
runtime | ||
samples | ||
sdk | ||
tests | ||
third_party | ||
tools | ||
utils | ||
.clang-format | ||
.gitattributes | ||
.gitconfig | ||
.gitignore | ||
.gn | ||
.mailmap | ||
.style.yapf | ||
.vpython | ||
AUTHORS | ||
BUILD.gn | ||
CHANGELOG.md | ||
codereview.settings | ||
CONTRIBUTING.md | ||
DEPS | ||
LICENSE | ||
OWNERS | ||
PATENT_GRANT | ||
PRESUBMIT.py | ||
README.dart-sdk | ||
README.md | ||
sdk_args.gni | ||
SECURITY.md | ||
WATCHLISTS |
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 dart.dev to learn more about the language, tools, and to find codelabs.
Browse pub.dev for more packages and libraries contributed by the community and the Dart team.
Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).
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.