Arguments default value

gistfile1.js

function func(a, f) {
    return function (args) {
        args.__proto__ = a;
        f.call(this, args);
    };
};


var f = func({foo : 10, bar : 20}, function (args) {
    print(args.foo, args.bar);
});

f({}); //10 20
f({foo : 50}); //50 20
f({foo : 50, bar : 50}); //50 50

@ArtS, they are not interchangeable in this instance.

@abozhilov

The idea of my pattern was to keep clean function's body.

In both my examples, you're only adding one line of code really. They're also very explicit about what they're doing.

I would argue that your function is less explicit and actually makes things much messier; by either creating a lot of noise at the point of function creation or clouding how the code works by decorating the function later on.

In the case of the former, you're now dealing with anonymous functions which make your stack traces less readable. Decorators are fine in principle, but in this case I just don't see the benefit. Obviously coders should use what they find most readable.

I do think this would be good for partial function application, or for modifying an existing function to take an object of arguments, etc.... I just don't think this should be used for giving functions default arguments and it definitely needs a more descriptive name.