We discussed this at length in the shakti mailing list [1]. This version by chrispsn is my favorite:

    {+/["\n"=x],+/[<':~x in "\n\r\t "],#x}

I think it's the one that more clearly express the intent. However, this other one by Attila Vrabecz performs better in the current version:

    {(+/x in"\n\n";+/0>':x in" \n\t\r";#x)}@1:"big.txt"

[1] https://groups.google.com/forum/?utm_medium=email&utm_source...