Extra XPointer features

• Instead of just nodes, XPointers address locations, which can be nodes, points, or ranges.

• A point can represent the location preceding or following any individual character in a chardata node.
  The special node test
    point()
  selects the set of points of a node.

• A range consists of two points in the same document,
  and is specified using a range expression of the form
    expr to expr.

• XPointer provides some extra functions:
  

  here()		get location of element containing current XPointer
  origin()		get location where user initiated link traversal
  start-point(location-set)		get start point of location set
  string-range(...)		find matching substrings
  ...

Example 1:

/descendant::text()/point()[position()=0]

selects the first character of all character data nodes in the document.

Example 2:

/section[1] to /section[3]

selects everything from the beginning of the first section to the end of the third.