simple test for string equality
simply forwards the current context, element\item specific versions exist that step downwards in document order
all children unpacked, normal xpath requires the context in E1/E2, which hugely complicates things, so \ is this, \+ is \ in the case where unpacking is needed which just leaves \* varieties for elements.
All descendants, uses XPathInfo eager to choose an implementation
Parents of these paths
filter through the current matches
Equivalent to [last() < n]
Equivalent to [last() = n]
Equivalent to [last() > n]
1 index based, per spec, but unsure if it should be
Equivalent to [position() < pos]
Equivalent to [position() > pos]
Equivalent to position() = last()
x prefixed to avoid disturbing the use of an xpath as an iterable
Base trait for XPath Axis, also provides common functionality