Wait

An Await implementation inspired by CSharp's await keyword discovered in the async support in nodejs article.

Install

haxelib git wait https://github.com/skial/wait.git

And add -lib wait to your hxml file.

Usage

You have two options, use Wait with Klas or not.

With Klas

package ;

class Main implements Klas {
	
	public function new() {
		@:wait asyncTask(100, 10000, [success], [error]);
		trace( success );
	}
	
	public function asyncTask(start:Int, finish:Int, success:String->Void, error:String->Void) {
		// Do something
	}
	
}

Without Klas

package ;

@:autoBuild( uhx.macro.Wait.build() )
class Main {
	
	public function new() {
		@:wait asyncTask(100, 10000, [success], [error]);
		trace( success );
	}
	
	public function asyncTask(start:Int, finish:Int, success:String->Void, error:String->Void) {
		// Do something
	}
	
}

Explanation

Wait transforms any method thats contains @:wait by taking all code after the encountered @:wait. It then inserts a local method whose body contains the captured code, before the encountered @:wait.

• Both [success] and [error] indicate to the build macro that these parameters are methods, both taking a single parameter themselves.
• The code @:wait callback(1, 2, [c, d, e]) tells the build macro to create a method that has three parameters named c, d and e.
• The marker [] can appear at any point in a method call @:wait callback(1, [a, b], 2, 3, [c], 4, [d, e])
• An empty marker, [] equals Void->Void.

The following example is the transformed method body of the constructor from the examples above.

public function new() {
    var block0 = function(?success:String, ?error:String) {
            trace(success);
    };
    asyncTask(100, 10000, block0.bind(_), block0.bind(null, _));
}

Tests

You can find Waits tests in the uhu-spec library.