Annotation Feature Wishes (Type Templates & Functions with Properties)

[Bernd Wessels]

Hi guys, here are two feature wishes regarding the Google Closure Library Annotation System.

1. Functions with properties

function iReturnAFunctionWithAdditionalProperties(a) {

  var x = a;

  var f = function(opt_b) {

    if(arguments.length == 0) return x;

    else x = opt_b;

  };

  f.hello = function(text){alert(text); return x;};

};

/**

 * @type {function(number=)}    Will not work in this case.

 */

var myF = iReturnAFunctionWithAdditionalProperties(4711);

myF(815);                  Valid JavaScript and works absolutely fine,

var test = myF();         BUT at the moment there is no way to

myF.hello('ola');          annotate this in a way that the closure compiler is happy.

I would suggest something like this to be added to the Closure Annotation:

/**

 * @param {number=} opt_value

 * @function

 */

MyLib.FunctionWithAdditionalProperties = function(opt_value) {};

/**

 * @param {string} text

 * @returns {number}

 */

MyLib.FunctionWithAdditionalProperties.prototype.hello(text) {};

In our example that would work like this:

/**

 * @type { MyLib.FunctionWithAdditionalProperties }

 */

var myF = iReturnAFunctionWithAdditionalProperties(4711);

myF(815);                  wow, great

var test = myF();         perfect

myF.hello();                wonderful

2. Type Templates

It is really hard to describe, but I would love some kind of type templates in the Google Closure Annotation System.

Here is an example:

/**

 * @param {template(0)} a

 * @param {template{1)} b

 * @param {string} c

 * @returns {template(1)}

 * @function

 */

MyLib.Something = function(a, b, c) { return b; };

/**

 * @type {MyLib.Something}

 * @template(0) {number}

 * @template(1) {string}

 */

var myF1 = MyLib.Something;

/**

 * @type {MyLib.Something}

 * @template(0) {Object}

 * @template(1) {number}

 */

var myF2 = MyLib.Something;

/**

 * @type {string}

 */

var test1 = myF1(17, 'seventeen', 'hello');

/**

 * @type {number}

 */

var test2 = myF2({grunz: 'ui'}, 48, 'hello');

Maybe somebody of the official Google Closure guys can tell me if that makes sense and if this here is the right place for Feature Wishes.

Best regards

Bernd