waitForOne.js

gistfile1.js

var galaxy = require('galaxy');

function *waitForOne(futures) {
	return yield galaxy.star(function(cb) {
		for (var i = 0; i < futures.length; i++) {
			galaxy.unstar(futures[i], 0)(function(e, r) {
				if (cb) cb(e, r);
				cb = null;
			});
		}
	}, 0)();
}

var sleep = galaxy.star(function(ms, cb) {
	setTimeout(cb, ms);
}, 1);

function *delay(ms, result) {
	yield sleep(ms);
	return result;
}

function *test() {
	var futs = [10, 4, 2, 6].map(function(i) {
		return galaxy.spin(delay(i * 100, i));
	});

	var result = yield waitForOne(futs);
	console.log("result=" + result);
}

galaxy.unstar(test)(function(err) {
	if (err) throw err;
});

waitForOne._js

"use strict";

function waitForOne(cb, futures) {
	for (var i = 0; i < futures.length; i++) {
		futures[i](function(e, r) {
			if (cb) cb(e, r);
			cb = null;
		});
	}
}

function delay(_, ms, result) {
	setTimeout(_, ms);
	return result;
}

function test(_) {
	var futs = [10, 4, 2, 6].map(function(i) {
		return delay(!_, i * 1000, i);
	});

	var result = waitForOne(_, futs);
	console.log("result=" + result);
}

test(function(err) {
	if (err) throw err;
});

added waitForOne._js: same example, but written with streamline.js