Re: References in XPath that can be representedbyastringandstill can be garbage collected

>>> I don't think so. For node identity, there is no issue with order of
>>> evaluation, the only constraint is some strictness about evaluating an
>>> expression the right number of times.
>>
>> I think these are very close issues:
>> ...
>
> Sure, they're related issues, but they aren't the same. As an implementer 
> there's a big difference between the two constraints - the latter leaves 
> many more optimisation approaches available. From a specification 
> perspective, the latter does not require the definition of a strict 
> execution order - therefore XPath 2.0 and XQuery do not have one.

I'm not an adorer of "resource manager" nor of "modifiable reference",
however, for the puropses of clarity can you please describle differences
in handling:
  a) expression depending on node identity;
  b) expression using xquery update (of a temporary tree);
  c) expression using modifiable reference?
--
Vladimir Nesterovsky
http://www.nesterovsky-bros.com/