Viewport too constrained?

The definition of p:viewport right now is constrained so that both the
input to the viewport and the output of each iteration of the subpipline
within it must be exactly one document.

Is there any reason to impose the second restriction?

It seems to me that if the result of applying the pipeline is an empty
sequence, that should be the same as deleting the content.

If the result is a sequence of documents, that should just turn into a
sequence of siblings.

Am I missing something?

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | Everything should be made as simple as
http://nwalsh.com/            | possible, but no simpler.