Type Checking?

Brendan Eich brendan at mozilla.org
Fri Oct 12 00:14:23 PDT 2007

On Oct 11, 2007, at 10:36 PM, Garrett Smith wrote:

> So that that's out of scope for ES4; it's OK for host objects to have
> custom behavior.

I'm afraid so, but we could say that host objects that are callable  
SHOULD be functions if they appear to be functions otherwise; we  
could say that all callable host objects MUST be compatible with the  
Callable structural type.

> quirksmode -- document.all works
> strict mode  -- no document.all
> It is detectable.

Sorry, you are right -- I didn't grok the document.compatMode  
reference, but yeah: based on DOCTYPE we either will resolve  
undetected document.all, or not.

>>> Mozilla really made document.all look like IE's weird
>>> collection-that-can-be-invoked-with-().
>> Like, yeah -- that was the point!
> Was heavily debated and implemented. Water under the bridge, right?

Way under. See



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