In message <f0314c659cd783e3f1a655cd7a5f9451 / ruby-forum.com>, Mike Fletcher writes:
>a = Array.new( 3 ) { |idx| Array.new() }

>That will call the block once for each element, and that block will 
>create a new (different) array instance each time it's called.

You could just do {[]} for the block.  It DWYM.

-s