?> There's a little more to it.
IE<9 actually creates 2 function objects when parsing NFE; not just leaks
identifier to the enclosing scope. It might seem irrelevant at first, but
if you consider that something like `var f = function g(){ ... } ` will
result in creation of 2 distinct function objects bound to `f` and `g`,
it's easy to imagine how this could lead to all kinds of lovely bugs (e.g.
when assigning to a property of function object; and having that property
on `f` but not `g`, or vice versa).
In addition, the leakage of that extra identifier is a memory leak in IE <=
8. If you create a lot of those NFE's like that, you'll leak a noticeable
amount of memory in IE.
John David-Dalton suggested this pattern (I believe) which clears up the
memory leakage:
var abc = function def() { ... };
...
// later, to make sure the memory is fully cleaned up:
abc = def = null;
But the fact that this was an issue all the way up through IE8 points out
that NFE's are not a complete cure-all for losing arguments.callee, because
they come with some unfortunate baggage in IE.
--Kyle
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