Stop storing contextual information on FunctionBody nodes.

Instead of using InferenceContext.getContext and
InferenceContext.setType to associate type inference information with
VariableDeclaration nodes, we pass the information on the stack using
a new FunctionBodyImpl.resolve method.  This should be more efficient
for two reasons: it avoids a map lookup, and it avoids the double
dispatch traditionally associated with calling a visitor.  It should
also make the code easier to reason about (since it makes the flow of
data in the type inference process more explicit).

This is part of a larger effort to elimiate the use of
InferenceContext.getContext and InferenceContext.setType entirely.

Change-Id: I8a3f3be940acdcd0a2c4ad8ec37b41bafe25c952
Reviewed-by: Konstantin Shcheglov <>
Commit-Queue: Paul Berry <>
4 files changed
tree: a05445f95b2fffb29ecc6c96d8a769d3f4529298
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. samples-dev/
  10. samples_2/
  11. sdk/
  12. tests/
  13. third_party/
  14. tools/
  15. utils/
  16. .clang-format
  17. .gitattributes
  18. .gitconfig
  19. .gitignore
  20. .gn
  21. .mailmap
  22. .packages
  23. .style.yapf
  24. .vpython
  28. codereview.settings
  29. compile_output.txt
  31. DEPS
  35. README.dart-sdk
  37. sdk_args.gni


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.


Using Dart

Visit to learn more about the language, tools, and to find codelabs.

Browse for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at, 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.