Select a subset of a given node-set by checking whether they satisfy one or more predicates.
A FilterExpr contains some PrimaryExpr which
constitutes a node-set, and optionally a predicate which filters the node-set
according to the predicate expression.
It corresponds to the expression FilterExpr defined in
XPath, Section 3.3, Rule
20.
Select all patients and relatives sharing the surname
"Atkins" (a SetExpr filtered by a
Predicate that selects all those names containing a
case-insensitive form of "Atkins"):
(/patient/name | /patient/nextofkin/name)[surname ~= 'Atkins']
Predicate |
PrimaryExpr |