Fixing instanceof (Array.isArray() etc.)?

[Brendan Eich]

> Axel Rauschmayer <mailto:axel at rauschma.de>
> January 21, 2012 10:13 PM
> Duck typing is an interesting consideration. If one could express
>
>      x follows ArraySpec
>
> then that would work for both array-like objects and Array instances 
> from other frames.

You're talking about contracts here. Not ready for standardization, but see

http://disnetdev.com/contracts.coffee/

/be