Thanks, Michael, If the simple map operator "does not locate any special nodes within trees, but works on sequences of items you specify by expressions", does that not make it into a sequence expression in the terms of Michael Kay's Reference, Chapter 10 (which also has "/" as a simple mapping expression when it works on atomic values)? Also, the draft defines a path expression as something that "can be used to locate nodes within trees", so I still wonder what the meaning behind this categorisation is.
Cheers, Jens On Jul 9, 2012, at 10:01 AM, Michael Seiferle wrote: > Hi Jens, > > they are relative, such that each step (E1 ! E2) will serve as the input > sequence E'1 for the next operation (E'1 ! E'2), hence: > >> <foo> >> <bar>hello</bar> >> <bar>world</bar> >> <bar>and</bar> >> <bar>hello</bar> >> <bar>universe</bar> >> </foo>/bar ! (: here we locate each <bar /> child of <foo /> :) >> upper-case(.) ! (: we return a sequence of their text() in upper-case :) >> substring(.,2,string-length(.)) (: we return a sequence of the >> upper case text and strip the first character :) > the map operator redefines the context items (inner focus) for each > subsequent operation. > > So it does not locate any special nodes within trees, but works on sequences > of items you specify by expressions, for example: >> (1 to 5) ! (. + 1) ! (. * 2) > will work as well and returns (4, 6, 8, 10, 12). > > Hope this helped to clear things up a little :-). > I guess others on this list will correct me if I got something wrong. > > Kind regards > > Michael > > > > Am 09.07.2012 um 09:41 schrieb Jens Østergaard Petersen: > >> Hi, >> >> Can anyone explain to me why the XQuery 3.0 simple map operator >> <http://www.w3.org/TR/xquery-30/#id-map-operator> is a relative path >> expression? Which nodes within trees does it locate? >> >> Thanks in advance for any enlightenment, >> >> Jens >> _______________________________________________ >> [email protected] >> http://x-query.com/mailman/listinfo/talk > _______________________________________________ [email protected] http://x-query.com/mailman/listinfo/talk
