gensy

GENSY

Asynchronous utils for Node.js/IO.js focused on generators.

1. Installation

Just run the following:

npm install gensy

Remember to add gensy as a dependency in your package.json file:

"dependencies": {
	...
	"gensy": "*"
	...
}

2. Usage

Simple generator

If you just want to run a generator to run some asynchronous code as if it were synchronous (by mean of the yield statement), just call gensy as follows:

var gensy = require('gensy');

gensy(function* (next) {
	try {
		...
		var x = yield foo(next);
		...
	} catch (error) {
		console.warn('Error:', error);
	}
});

Where foo is supposed to be an asynchronous function that uses next as a callback following the error+result arguments convention:

function foo(callback) {
	...
	return callback(error, result);
}

If an error is returned by foo, then generator's catch block will be executed.

This usage supports a callback to listen generator end. To use it the generator must call done() (a second argument) when finished:

var gensy = require('gensy');

function* genA(next, done) {
	try {
		var x = yield foo(next);
		...
		return done();
	} catch (error) {
		console.warn('Error:', error);
	}
}

gensy(genA);

Generator series

To run a list of generators, one by one, use gensy.series() as follows:

var gensy = require('gensy');

function* genA (next, done) {
	try {
		var x = yield foo(next);
		...
		return done();
	} catch (error) {
		console.warn('Error:', error);
	}
}

function* genB (next, done) {
	try {
		var x = yield foo(next);
		...
		return done();
	} catch (error) {
		console.warn('Error:', error);
	}
}

gensy.series([genA, genB], function () {
	console.log('Series ended');
});