On Dec 2, 2013, at 7:51 PM, Andrea Giammarchi wrote:
> Reading this:
> http://esdiscuss.org/topic/november-19-2013-meeting-notes#content-6
>
> I was wondering if anyone would be so kind to provide a concrete/real-world
> use case for toMethod() since I am having hard time to imagine a scenario
> where a super can be so easily invoked, being (AFAIK) multiple inheritance
> not allowed right now in ES6 specs.
toMethod is a low level primitive that can be used to implement things like
Object.mixin in a manner that works correctly with functions that reference
super.
>
> When exactly would a piece of code invoke a super withou knowing which one is
> it?
Anytime you want to before/after/around wrap a call to the the method that
would otherwise be invoked.
Anytime you want to define a "mixin" on an object with a known interface but
multiple implementations.
>
> Wouldn't this lead to potential infinite loop within the super invocation
> itself if referenced from a subclass that was already using toMethod() within
> the super() itself?
There is a potential for a super invocation-based unbounded recursion loops,
but it doesn't require the use to toMethod to make it occur. consider
class P { }
class C extends P {
foo() {
console.log("f");
super();
}
}
P.prototype.foo=C.prototype.foo;
(new C).foo(); //infinite recursion outputting lines of f's
If instead you coded:
P.prototype.foo = C.prototype.foo.toMethod(P.prototype);
you would not get the infinite recursion, instead you would get two f's
followed by a "method not found" .
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