[xsl] How to process a sequence of any type as input of a transformation?

["Olivier Jeulin olivier.jeulin.work@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hello,

according to http://www.exselt.net/features/new-in-xslt-30/
bAny sequence of any type can be the input for the transformation, not just
a document.b

I haven't found a clear statement of that in the norm, but I'd like to use
this feature (using Saxon, so if the solution is specific, we can switch to
the Saxon mailing list).

My use case is to read text lines from the output of another program using
a pipe (GNU/linux):
someProg | xsltProcessor x.xsl

where the output of someProg is
line1
line2
b&
(I know how to do that using a parameter, or a file)

How can I access such a sequence from a stylesheet?