While I don't know why (efficiency, I presume, or simplicity, or simply nobody tought about it, or whatever), I was thinking that recursively applying the smart match on each individual element would allow smart-matching over a "complicated" data structure, like a matrix. Something like:

   42 ~~ [
           [ 0  .. 9 ],
           [ 20 .. 29 ],
           [ 40 .. 49 ],
         ]
[download]

I'm still wondering if this could be named a feature or a bug, anyway :D