Aptana Studio 3.2.2 (and probably other 3.x versions) will show no outline.
If commenting the line with the E4X statement in, the outline will be shown.
Aptana Studio 2.0.5 supports E4X and will display an outline, even with the offending line.
For Aptana Studio 2.0.5 it seems to matter if the statement ends with ()) or )() - for 3.2.2 it does not seem to matter.
It would be very nice if 3.x had a working outline for E4X. This is holding us back for upgrading.
We are aware that E4X is going to be removed, but we estimate we will be working with it for at least another two years.