On Sep 12, 2014, at 8:55 PM, Erik Arvidsson wrote: > > On Sep 12, 2014 6:39 PM, "Jason Orendorff" <[email protected]> wrote: > > > > On Thu, Sep 11, 2014 at 4:15 PM, Allen Wirfs-Brock > > <[email protected]> wrote: > > > `new^` is lexically scoped, just this `this` and `super`. If an arrow > > > function references `new^` it is the value of the closest lexically > > > enclosing constructor function (a function that implements [[Construct]]). > > > > > > Just like [[Get]] and [[Set]], the trap for [[Construct]] is extended to > > > include a "receiver" parameter. > > > > Thanks. The analogy to [[Get]] and [[Set]] helps a lot. > > > > (Superficially, possible alternatives to `new^` could include > > `class()` and `class this`.) > > > > One more minor question. Suppose I mistakenly type: > > > > class ColorPoint extends Point { > > constructor(x, y, color) { > > this = super(x, y); // oops: should be `new super(x, y)` > > this.color = color; > > } > > } > > > > Then `new ColorPoint(0, 0, "red")` throws a ReferenceError, because > > `super(x, y)` implicitly uses `this`. Is that right? Asking just > > because it seems like it'd be an easy mistake to make. > > It will [[Call]] Point instead of [[Construct]] which may or may not work > depending on how Point is defined. > > >
No, Jason was correct. It would get a Reference Error because `super(x,y)` implicitly tries to pass `this` which is still in its TDZ. Allen
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