slide 15

In XPath 2.0 We Have
Sequences of Items

• XPath 2.0 does not center on a single document tree, but on arbitrary data sets
• These can be arranged in sequences of items
  • sequences are lists, ordered sets of
    • pointers to nodes (which still have identity) and
    • simple-typed values
  • may contain duplicates
• count($node-set) = count($node-set | $node-set) is still true
  (due to semantics of “|”, the union operator)
• But now we can also say ($node-set , $node-set)
  • A sequence of all the nodes in $node-set (in document order), then all the same nodes again