Async/Await feature in Dart 1.8

Update 2

The most recent nightly build also supports async*

void main() {  generate().listen((i) => print(i));}Stream<int> generate () async* {  int i = 0;  for(int i = 0; i < 100; i++) {    yield ++i;  }}

Update

yield and yield* in a method marked sync* (returning an Iterable) are already supported in 1.9.0-edge.43534

void main() {  var x = concat([0, 1, 2, 3, 4], [5, 6, 7, 8, 9]);  // x is an Iterable which iterates over the values 1 to 9  print(x);}// A method marked `sync*` returns an `Iterable`concat(Iterable left, Iterable right) sync* {  yield* left;  yield* right;}

void main() {  print(filter([0, 1, 2, 3, 4, 5], (x) => x.isEven));}filter(ss, p) sync* {  for (var s in ss) {    if (p(s)) yield s;  }}

async* generator functions (returning a Stream) are not yet supported.

Original

Basic support is already available.
See https://www.dartlang.org/articles/await-async/ for more details.

main() async {  // await  print(await foo());  try {    print(await fooThrows());  } catch(e) {    print(e);  }  // await for  var stream = new Stream.fromIterable([1,2,3,4,5]);   await for (var e in stream) {     print(e);   }}foo() async => 42;fooThrows() async => throw 'Anything';