Axis steps

The basic primitive for accessing a source document is the axis step. Axis steps may be combined into path expressions using the path operators / and //, and they may be filtered using filter expressions in the same way as the result of any other expression.

An axis step has the basic form axis :: node-test, and selects nodes on a given axis that satisfy the node-test. The axes available are:

ancestor	Selects ancestor nodes starting with the current node and ending with the document node
ancestor-or-self	Selects the current node plus all ancestor nodes
attribute	Selects all attributes of the current node (if it is an element)
child	Selects the children of the current node, in documetn order
descendant	Selects the children of the current node and their children, recursively (in document order)
descendant-or-self	Selects the current node plus all descendant nodes
following	Selects the nodes that follow the current node in document order, other than its descendants
following-sibling	Selects all subsequent child nodes of the same parent node
namespace	Selects all the in-scope namespaces for an element (this axis is deprecated in XPath 2.0, but Saxon continues to support it)
parent	Selects the parent of the current node
preceding	Selects the nodes that precede the current node in document order, other than its ancestors
preceding-sibling	Selects all preceding child nodes of the same parent node
self	Selects the current node

When the child axis is used, child:: may be omitted, and when the attribute axis is used, attribute:: may be abbviated to @. The expression parent::node() may be shortened to ..

The expression . is no longer synonymous with self::node(), since it may now select items that are not nodes. If the context item is not a node, any use of a path expression will raise an error.

The node-test may be, for example:

a node name
prefix:* to select nodes in a given namespace
*:localname to select nodes with a given local name, regardless of namespace
text() (to select text nodes)
node() (to select any node)
processing-instruction() (to select any processing instruction)
processing-instruction('literal') to select processing instructions with the given name (target)
comment() to select comment nodes
element() or element(*) to select any element node
element(N) to select any element node named N
element(*, T) to select any element node whose type annotation is T, or a subtype of T
element(N, T) to select any element node whose name is N and whose type annotation is T, or a subtype of T
schema-element(N) to select any element node whose name is N, or an element in the substitution group of N, that conforms to the schema-defined type for a global element declaration named N in an imported schema
attribute or attribute(*) to select any attribute node
attrbute(N) to select any attribute node named N
attribute(*, T) to select any attribute node whose type annotation is T, or a subtype of T
attribute(N, T) to select any attribute node whose name is N and whose type annotation is T, or a subtype of T
schema-attribute(N) to select any attribute node whose name is N, that conforms to the schema-defined type for a global attribute declaration named N in an imported schema