On 10/10/07, Brendan Eich <[EMAIL PROTECTED]> wrote: > On Oct 10, 2007, at 3:53 PM, Garrett Smith wrote:
> > if (it is Callable) ... > > > The |is| operator tests universal or Platonic type, which involves > shared, immutable type descriptors that do not vary across windows or > frames. So > > if (a is Array) ... > > will work no matter where a was constructed. > I wonder how host objects will deal with this. Will there be a transitive relationship of callable and ()? If an object accepts arguments, it is callable, and if it is callable, it supports ,call(), right? typeof appendChild; // "object" appendChild is Callable; // ??? In IE, appendChild.call is undefined, yet accepts arguments. It's like a host function that's bound, internally, to its node. Its thisArg is always the node; execution context is irrelevant. It's an odd duck. document.all(), document.links(0) are also non-functional, but "do something" when you use arguments (). That something is not [[call]]. Opera mimicked this odd behavior with document.all and Mozilla did too in BackCompat mode. Hosts that create such objects create a deceptive and confusing interface. It's like "what the heck is this thing?" Garrett > /be > > -- Programming is a collaborative art. _______________________________________________ Es4-discuss mailing list Es4-discuss@mozilla.org https://mail.mozilla.org/listinfo/es4-discuss
