Skip to main content

Dart Language Nears M1 State

Posted by Seth Ladd

Dart Team Updates - August 18-Sept 4th


Learn more at http://dartlang.org

Summary
  • The language spec is nearing its M1 state, the core libraries have been unified, the VM and dart2js implement more M1 features, and the editor improves on static analysis, refactorings, and quick fixes.

Details

Dart language specification:
  • 0.11 spec nearing completion: all M1 features covered.

Dart libraries [core, unittest, i18n, etc]:
  • The core and coreimpl libraries have been unified across dart2js and the VM. There are still implementation-dependent sources, but there is only one corelib and the SDK only contains implementation-independent files.

Dart VM:
  • New compiler: Deoptimization support, class hierarchy analysis, unboxing of doubles in select instructions, smi and class check elimination, stackmaps for live registers and simple inlining.
  • Language features: Argument definition test (aka '?' prefix operator), abstract class handling, disabled legacy try-catch.
  • Started removal of explicit interfaces in core library code, added Expando implementation.
  • Tuned performance of string operations and native calls.
  • Working down the queue of security fixes.
  • Resolved a few stability issues caused by missing store barriers.

Dart to JavaScript Compiler:
  • Language features: Added support for annotations (metadata), enabled calling non-functions through the call method, removed #resource directive.
  • Re-triaged all bugs so we have a clearer picture on what goes into the M1 release.

Dart Editor:
  • M1 language migration wizard: Right click on your project and choose 'Clean up...'. We've implemented cleanups for catch blocks, the new getter syntax, operator equals, and library/import/source changes.
  • Dart syntax highlighting in the compare and refactoring dialogs.
  • Dart Editor build hook. If a build.dart script exists in a project, we'll invoke it as part of the Editor's build process. This allows for custom processing of changed resources, like for templating systems, generating Dart code, or scss --> css processing. There are sample scripts available at dart/samples/buildhook1 and dart/samples/buildhook2, as well as online at https://github.com/dart-lang/dart-web-components/blob/master/build.dart.
  • Our type inference engine has been enhanced to add support for inferring types from dart:html select().
  • The type inference engine now handles the case where a variable is assigned different types at different times, and will show you the intersection of legal method and field references. In addition we now infer the type of List and Map literals.
  • Added basic scss (http://sass-lang.com/) syntax highlighting.
  • dart:mirrors has been added to the SDK; the editor can now resolve the mirrors library and the types within it.
  • Added warnings for use of obsolete getter and catch syntaxes.
  • We now highlight single line /// dartdoc comments.
  • We now do a better job of displaying when the debugger halts at an uncaught exception.
  • The Editor workspace location has changed. The workspace is where we store information about your open files and folders. We had stored this in a 'workspace' directory co-located with the Editor application. We now always locate it in the user's home directory. The first time you run this new build you'll have to re-open the folders you had been working on. For more info, see http://www.dartlang.org/docs/editor/#settings.
  • Several libraries have moved from dart-sdk/lib to dart-sdk/pkg. This means that they will not show up in the Files view and will no longer be accessible (erroneously) as a dart: import. You'll want to use pub to access these pkg libraries.
  • 17 analysis issues fixed, as well as ongoing changes to support the M1 language.
  • General fixes and enhancements to the rename refactoring, code completion, the extract variable refactoring, hyperlinking, searchbox UX, and the debugger UX.

Dart UI [dart:html, web components]:
  • XMLHttpRequest is now HttpRequest. Because seriously, when is the last time you sent XML over XMLHttpRequest? :)

Dart SDK and build:
  • SDK no longer contains VM-specific files for core and coreimpl libraries.

Pub:
  • Lots of bug fixing (7 issues fixed, more merged or re-routed).
  • More pub documentation.
  • Move some internal packages (args, yaml, etc.) over to pub.dartlang.org.
  • Dogfood pub.dartlang.org with Dart team.

Dart Server [dart:io, etc.]:
  • Bug fixes.
  • Work in progress on HTTPS support.

Dev Rel:
    • Updating Language Tour and book to M1

Comments

Popular posts from this blog

Const, Static, Final, Oh my!

Posted by Seth Ladd

(This is an "oldie but a goodie" misc@dartlang.org post originally written by Bob Nystrom. It is being posted here as the explanations still ring true.)

Bob writes:


"static", "final", and "const" mean entirely distinct things in Dart:

"static" means a member is available on the class itself instead of on instances of the class. That's all it means, and it isn't used for anything else. static modifies *members*.

"final" means single-assignment: a final variable or field *must* have an initializer. Once assigned a value, a final variable's value cannot be changed. final modifies *variables*.

"const" has a meaning that's a bit more complex and subtle in Dart. const modifies *values*. You can use it when creating collections, like const [1, 2, 3], and when constructing objects (instead of new) like const Point(2, 3). Here, const means that the object's entire deep state can be determ…

The new AdWords UI uses Dart — we asked why

Google just announced a re-designed AdWords experience. In case you’re not familiar with AdWords: businesses use it to advertise on google.com and partner websites. Advertising makes up majority of Google’s revenue, so when Google decides to completely redo the customer-facing front end to it, it’s a big deal. The Dart team is proud to say that this new front end is built with Dart and Angular 2. Whenever you asked us whether Google is ‘even using Dart for anything,’ this is what we had in mind but couldn’t say aloud. Until now. We asked Joshy Joseph, the primary technical lead on the project, some questions. Joshy is focusing on things like infrastructure, application latency and development velocity, so he’s the right person to ask about Dart.Q: What exactly did we launch on Monday?It’s a complete redesign of the AdWords customer experience that is rolling out slowly as a test to a small initial set of advertisers. The most noticeable thing is probably the Material Design look and f…

Dart 1.12 Released, with Null-Aware Operators and more

Dart 1.12.0 is now released! It contains the new null-aware operators language feature, and enhancements to pub, Observatory, dartdoc, and much more.

Null-aware operators

The new null-aware operators help you reduce the amount of code required to work with references that are potentially null. This feature is a collection of syntactic sugar for traversing (potentially null) object calls, conditionally setting a variable, and evaluating two (potentially null) expressions.

Click or tap the red Run button below to see them in action.

??

  if null operator. `expr1 ?? expr2` evaluates to `expr1` if not `null`, otherwise `expr2`.


??=

  null-aware assignment. `v ??= expr` causes `v` to be assigned `expr` only if `v` is `null`.

x?.p

  null-aware access. `x?.p` evaluates to `x.p` if `x` is not `null`, otherwise evaluates to `null`.

x?.m()

  null-aware method invocation. `x?.m()` invokes `m` only if `x` is not `null`.

Learn more about Dart's null-aware operators in our Language Tour.

.packages fi…