async-await
Advanced tools
aa - async-await. co like library, go like channel, thunkify or promisify wrap package.
aa - async-await library.
co like library, go like channel, thunkify or promisify wrap package.
using ES6 (ES2015) generator function.
compatible with co@3 and co@4.
$ npm install aa --save
or
$ npm install async-await --save
var aa = require('aa');
// or
var aa = require('async-await');
basic usage.
you can aa() promises, generators, and generator functions.
aa(function *() {
// *** SEQUENTIAL EXECUTION ***
// yield value returns itself
yiled 1;
yiled [1, 2, 3];
yiled {x:1, y:2, z:3};
// yield promise returns resolved value
yield Promise.resolve(1);
// or throws rejected error
try { yield Promise.reject(new Error('expected')); }
catch (e) { console.error('%s', e); }
// *** PARALLEL EXECUTION ***
// yield an array of promises waits all promises and returns resolved array
yield [Promise.resolve(1), Promise.resolve(2)];
// yield an object of promises waits all promises and returns resolved object
yield {x: Promise.resolve(1), y: Promise.resolve(2)};
// *** OTHERS AND COMBINED OPERATIONS ***
// yield thunk
// yield generator or generator function
// yield channel for event stream
});
promisify() converts node style function into a function returns promise.
you can use fs.exists() and child_process.exec() also.
thunkify() converts node style function into a thunkified function.
you can use fs.exists() and child_process.exec() also.
Channel() returns a new channel for event stream.
use a channel for node style function as a callback.
yield channel for wait it.
you can yield promises, thunkified functions,
generators, generator functions,
primitive values, arrays, and objects.
$ node aa-readme-ex01-seq.js
var aa = require('aa');
aa(main);
function *main() {
console.log('11:', yield asyncPromise(100, 11));
console.log('12:', yield asyncThunk(100, 12));
console.log('13:', yield asyncGenerator(100, 13));
yield sub(20);
yield sub(30);
}
function *sub(base) {
console.log('%s: %s', base + 1, yield asyncPromise(100, base + 1));
console.log('%s: %s', base + 2, yield asyncThunk(100, base + 2));
console.log('%s: %s', base + 3, yield asyncGenerator(100, base + 3));
}
// asyncPromise(msec, arg) : promise
function asyncPromise(msec, arg) {
return new Promise(function (resolve, reject) {
setTimeout(resolve, msec, arg);
});
}
// asyncThunk(msec, arg) : thunk
function asyncThunk(msec, arg) {
return function (callback) {
setTimeout(callback, msec, null, arg);
};
}
// asyncGenerator(msec, arg) : generator
function *asyncGenerator(msec, arg) {
var chan = aa.Channel();
setTimeout(chan, msec, arg);
return yield chan;
}
$ node aa-readme-ex02-par.js
var aa = require('aa');
aa(main);
function *main() {
console.log('[11, 12, 13]:', yield [
asyncPromise(100, 11),
asyncThunk(100, 12),
asyncGenerator(100, 13)
]);
console.log('{x:11, y:12, z:13}:', yield {
x: asyncPromise(100, 11),
y: asyncThunk(100, 12),
z: asyncGenerator(100, 13)
});
yield [sub(20), sub(30)];
}
function *sub(base) {
console.log('%s: %s', base + 1, yield asyncPromise(100, base + 1));
console.log('%s: %s', base + 2, yield asyncThunk(100, base + 2));
console.log('%s: %s', base + 3, yield asyncGenerator(100, base + 3));
}
// asyncPromise(msec, arg) : promise
function asyncPromise(msec, arg) {
return new Promise(function (resolve, reject) {
setTimeout(resolve, msec, arg);
});
}
// asyncThunk(msec, arg) : thunk
function asyncThunk(msec, arg) {
return function (callback) {
setTimeout(callback, msec, null, arg);
};
}
// asyncGenerator(msec, arg) : generator
function *asyncGenerator(msec, arg) {
var chan = aa.Channel();
setTimeout(chan, msec, arg);
return yield chan;
}
$ node aa-readme-ex11-promisify.js
var aa = require('aa');
var promisify = aa.promisify;
var asyncPromise = promisify(asyncCallback);
aa(main);
function *main() {
console.log('11:', yield asyncPromise(100, 11));
console.log('12:', yield asyncPromise(100, 12));
console.log('13:', yield asyncPromise(100, 13));
asyncPromise(100, 21)
.then(function (val) {
console.log('21:', val);
return asyncPromise(100, 22);
})
.then(function (val) {
console.log('22:', val);
return asyncPromise(100, 23);
})
.then(function (val) {
console.log('23:', val);
});
}
// asyncCallback(msec, arg. callback) : node style normal callback
// callback : function (err, val)
function asyncCallback(msec, arg, callback) {
setTimeout(callback, msec, null, arg);
}
$ node aa-readme-ex12-thunkify.js
var aa = require('aa');
var thunkify = aa.thunkify;
var asyncThunk = thunkify(asyncCallback);
aa(main);
function *main() {
console.log('11:', yield asyncThunk(100, 11));
console.log('12:', yield asyncThunk(100, 12));
console.log('13:', yield asyncThunk(100, 13));
asyncThunk(100, 21)
(function (err, val) {
console.log('21:', val);
asyncThunk(100, 22)
(function (err, val) {
console.log('22:', val);
asyncThunk(100, 23)
(function (err, val) {
console.log('23:', val);
});
});
});
}
// asyncCallback(msec, arg. callback) : node style normal callback
// callback : function (err, val)
function asyncCallback(msec, arg, callback) {
setTimeout(callback, msec, null, arg);
}
$ node aa-readme-example.js
var aa = require('aa');
// sleep(msec, args,... callback) : node style normal callback
// callback : function (err, val)
function sleep(msec) {
var args = [].slice.call(arguments, 1);
setTimeout.apply(null, [args.pop(), msec, null].concat(args));
}
sleep(1000, function (err, val) { console.log('1000 msec OK'); });
// delay(msec, args,...)(callback) : thunk
// callback : function (err, val)
function delay(msec) {
var args = [].slice.call(arguments);
return function (callback) {
sleep.apply(null, args.concat(callback));
};
}
// var delay = aa.thunkify(sleep);
delay(1100)(
function (err, val) { console.log('1100 msec OK'); }
);
// aa.promisify(fn) : returns wrapped function a.k.a thunkify and promisify
// wait(msec, args,...) : returns promise & thunk
var wait = aa.promisify(sleep);
// wait() : as a thunk
wait(1200)(
function (err, val) { console.log('1200 msec OK'); }
);
// wait() : as a promise
wait(1300).then(
function (val) { console.log('1300 msec OK'); },
function (err) { console.log('1300 msec NG', err); }
).catch(
function (err) { console.log('1300 msec NG2', err); }
);
// aa(generator) : returns promise & thunk
aa(function *() {
yield 1; // primitive value
yield [1, 2, 3]; // array
yield {x:1, y:2, z:3}; // object
// wait for promise
yield Promise.resolve(2);
// wait for thunk
yield delay(800);
// wait for promise or thunk
yield wait(800);
console.log('0:', yield wait(300, 0));
console.log('1:', yield wait(300, 1));
// yield Promise.all([])
console.log('[1, 2, 3]:',
yield Promise.all([wait(200, 1), wait(300, 2), wait(100, 3)]));
// yield [] -> like Promise.all([]) !
console.log('[4, 5, 6]:',
yield [wait(200, 4), wait(300, 5), wait(100, 6)]);
// yield {} -> like Promise.all({}) !?
console.log('{x:7, y:8, z:9}:',
yield {x:wait(200, 7), y:wait(300, 8), z:wait(100, 9)});
// make channel for sync - fork and join
var chan = aa.Channel();
sleep(300, 20, chan); // send value to channel : fork or spread
sleep(200, 10, chan); // send value to channel : fork or spread
var a = yield chan; // recv value from channel : join or sync
var b = yield chan; // recv value from channel : join or sync
console.log('10 20:', a, b);
// fork thread - make new thread and start
aa(function *() {
yield wait(200); // wait 200 msec
return 200;
})(chan); // send 200 to channel : join or sync
// fork thread - make new thread and start
aa(function *() {
yield wait(100); // wait 100 msec
return 100;
})(chan); // send 100 to channel : join or sync
// fork thread - make new thread and start
aa(function *() {
yield wait(300); // wait 300
return 300;
})(chan); // send 300 to channel : join or sync
// join threads - sync threads
var x = yield chan; // wait & recv first value from channel
var y = yield chan; // wait & recv second value from channel
var z = yield chan; // wait & recv third value from channel
console.log('top 3 winners: 100 200 300:', x, y, z);
// communicate with channels
var chan1 = aa.Channel(), chan2 = aa.Channel();
// thread 1: send to chan1, recv from chan2
aa(function *() {
sleep(100, 111, chan1);
console.log('222:', yield chan2);
sleep(100, 333, chan1);
console.log('444:', yield chan2);
sleep(100, 555, chan1);
return 666;
})(chan);
// thread 1: recv from chan1, send to chan2
aa(function *() {
console.log('111:', yield chan1);
sleep(100, 222, chan2);
console.log('333:', yield chan1);
sleep(100, 444, chan2);
console.log('555:', yield chan1);
return 777;
})(chan);
console.log('666 777:', yield chan, yield chan);
return 11;
})
.then(
function (val) {
console.log('11 val:', val);
return wait(100, 22); },
function (err) {
console.log('11 err:', err);
return wait(100, 22); }
)
(function (err, val) {
console.log('22 val:', val, err ? 'err:' + err : '');
return wait(100, 33); })
(function (err, val) {
console.log('33 val:', val, err ? 'err:' + err : '');
return wait(100, 44); })
.then(
function (val) {
console.log('44 val:', val);
return wait(100, 55); },
function (err) {
console.log('44 err:', err);
return wait(100, 55); }
)
.catch(
function (err) {
console.log('55 err:', err);
return wait(100, 66); }
);
MIT
FAQs
aa - async-await. co like library, go like channel, thunkify or promisify wrap package.
The npm package async-await receives a total of 122 weekly downloads. As such, async-await popularity was classified as not popular.
We found that async-await demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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