[basex-talk] Order of nodes in reversed axes

Hello all,

I've been looking for an authoritative answer to this, but have been unable to find one.

I'm trying to reliably get the nearest ancestor of a node. ie with this test data:

let $test := element test { attribute id { 4 }, element test { attribute id { 3 }, element test { attribute id { 2 }, element test { attribute id { 1 }, element child { } } } } }

i want an expression that will return node test/@id=1 from child.

Stackoverflow says that this:

$test//child/ancestor-or-self::test[ last() ]

Should work (herehttp://stackoverflow.com/questions/6554488/how-to-get-the-nearest-ancestor-or-child-of-an-ancestor-with-xpath), but since I couldn't find any indication to reversed axes being ordered in the w3c spec for reverse axes in xpath 2.0 (herehttp://www.w3.org/TR/xpath20/#doc-xpath-ReverseAxis), I suspected that this would be implementation dependent, and sure enough, in BaseX, that expression returns

<test id="4"> <test id="3"> <test id="2"> <test id="1"> <child/> </test> </test> </test> </test>

while this

$test//child/ancestor-or-self::test[ 1 ]

​correctly returns

<test id="1"> <child/> </test>​

Is there an authoritative way of getting the nearest ancestor of a given node? Note that in my actual use case, names are the same, and desired ids are unknown.

Thanks!

jta