On Dec 9, 2013, at 9:28 AM, James Long wrote:

> I read Allen's email wrong, thought it implied `this` was lexically
> scoped (which I know is not true. very little sleep at an airport...).
> 
> I'll keep digging through the spec, but if someone has a quick example
> what ES5 code I could compile to for roughly the same semantics, that
> would be helpful. From what I understand, you're saying that `super`
> is lexically scoped to the `class` that is defined so I can statically
> compile it out to something like `Foo.prototype.method` if `Foo` is
> the parent class. Anyway, no need to trail on about this, I should
> just RTFS

For an instance method defined in a class definition, [[Home]] is the instance prototype object defined by the class.  For a static method defined in a class definition [[Home]] is the class object (ie, the constructor function) itself.

super is not equivalent to a static reference to the super class or super class prototype be super must remain sensitive to prototype chain changes performed using Object.setPrototypeOf()

One way you can approximate [[Home]] in ES5 is to create a __Home property on the function objects that represent  methods.  Because [[Home]] never changes the __Home property could be non-writable, non-configurable.

At the last TC39 meeting there some decisions made about the use of super outside of class definitions.  Those decisions are not yet reflected in the ES6 draft.

Allen

On Dec 9, 2013, at 9:28 AM, James Long wrote:

> I read Allen's email wrong, thought it implied `this` was lexically
> scoped (which I know is not true. very little sleep at an airport...).
> 
> I'll keep digging through the spec, but if someone has a quick example
> what ES5 code I could compile to for roughly the same semantics, that
> would be helpful. From what I understand, you're saying that `super`
> is lexically scoped to the `class` that is defined so I can statically
> compile it out to something like `Foo.prototype.method` if `Foo` is
> the parent class. Anyway, no need to trail on about this, I should
> just RTFS

For an instance method defined in a class definition, [[Home]] is the instance prototype object defined by the class.  For a static method defined in a class definition [[Home]] is the class object (ie, the constructor function) itself.

super is not equivalent to a static reference to the super class or super class prototype be super must remain sensitive to prototype chain changes performed using Object.setPrototypeOf()

One way you can approximate [[Home]] in ES5 is to create a \_\_Home property on the function objects that represent  methods.  Because [[Home]] never changes the \_\_Home property could be non-writable, non-configurable.

At the last TC39 meeting there some decisions made about the use of super outside of class definitions.  Those decisions are not yet reflected in the ES6 draft.