[xquery-talk] Tales of the unexpected version III - Atomization

[David Carlisle]

On 08/01/2014 15:38, Ihe Onwuka wrote:
> because it is going to end up (by whatever process) as an attribute
> node.


That seems to be the cause of your confusion (and your misreading of the
spec and Mike Kay's book) If you go <foo>{$d/@*}</foo> You are _not_
copying nodes to a context where atomic values are expected, you are
copying them to an element node constructor, which is expecting nodes.

If the sequence were atomized (implicitly or by explicit use of data()
or string() then it would not "end up by any process as an attribute
node", it would make text node child of the element (which is why I
assumed originally that was what you intended to generate).

Implicit atomization would do the same as

<foo>{$d/@*/data()}</foo>

and the odd thing is you have said repeatedly that data() solved your
problem, but that will not generate any attribute nodes, the values of
the attributes will be concatenated as text node child of <foo>.


Had you gone <foo bar="{$d/@*}"/> then you are copying to such a
context, and atomization would be automatic and you would get the result
you want.

The FLWOR expression and group by clause are not really
relevant to the issue, you get the same behaviour (and same error
messages) without any grouping.

David


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