Reland "[dart:js_interop] Remove Object.toJS and JSNumber.toDart"

This is a reland of commit 16fcfe7eae9dcf0d2b4d7adf1ed9d3282f0344a0

Original change's description:
> [dart:js_interop] Remove Object.toJS and JSNumber.toDart
>
> Modifies JSBoxedDartObject reified type on JS backends and also
> modifies JSBoxedDartObject.toDart now that a proper box is introduced.
> Also uses a JS symbol in JSBoxedDartObject.toDart for a property
> check so that different Dart apps don't accidentally share Dart
> objects. It's now an error to call this function on non-boxed objects.
>
> Fixes a type issue where creating a new object literal with the JS
> foreign function was resulting in dart2js thinking toJSBox would
> always throw. Changing the typeDescription to PlainJavaScriptObject
> instead of =Object fixes that issue.
>
> CoreLibraryReviewExempt: Backend-specific library.
> Change-Id: I5cfb1f32ff4328fafdf9831b0d8da806c39391d9
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/309082
> Reviewed-by: Joshua Litt <joshualitt@google.com>
> Commit-Queue: Srujan Gaddam <srujzs@google.com>

CoreLibraryReviewExempt: Reland.
Change-Id: If6b190f12bdf840b0259c5739f50d9bdcd27fd47
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/313600
Reviewed-by: Joshua Litt <joshualitt@google.com>
Commit-Queue: Srujan Gaddam <srujzs@google.com>
10 files changed
tree: 6eaeec4b284af4525c5a4cd2b1828efdf714e946
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. .vpython
  22. AUTHORS
  23. BUILD.gn
  24. CHANGELOG.md
  25. codereview.settings
  26. CONTRIBUTING.md
  27. DEPS
  28. LICENSE
  29. OWNERS
  30. PATENT_GRANT
  31. PRESUBMIT.py
  32. README.dart-sdk
  33. README.md
  34. sdk.code-workspace
  35. sdk_args.gni
  36. SECURITY.md
  37. WATCHLISTS
README.md

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).

Dart platforms illustration

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.