[basex-talk] BaseX 7.3: unexpected Stack Overflow

[Torsten Grust]

Hi Christian,

On 18 Sep 2012, at 12:39, Christian Grün wrote:
> Dear Torsten,
>
> thanks for the bug report, always welcome. The issue is related to the
> "Info View" in the GUI or, more exactly, the generation of the query
> plan, which was triggering a recursive loop. It was running fine when
> the Info View was deactivated (which was the reason why I first
> couldn't reproduce the issue locally).
>
> We haven't implemented yet a general solution to the core issue (which
> is discussed in [1] in more detail). Instead, I have just uploaded a
> latest stable snapshot, which will simply skip some details in the
> serialized query plan, and won't raise any errors anymore.

many thanks for the quick reply.  Deactivating the Info View also
fixes the problem for me -- a solution that's good enough for now.

I've found support for h-o functions in BaseX to be perfectly stable,
otherwise.

Thanks again,
    --Torsten

> On Tue, Sep 18, 2012 at 10:02 AM, Torsten Grust 
> <torsten.grust at gmail.com> wrote:
>> Dear all,
>>
>> I have been playing with the following toy implementation
>> of a super-simple associative map (it's mainly an exercise
>> in demonstrating the use of h-o functions in XQuery 3.0):
>>
>>> declare namespace map = "http://db.inf.uni-tuebingen.de/map";
>>>
>>> declare function map:entry($map, $k, $v) {
>>> function($x) { if ($x eq $k) then $v else $map($x) }
>>> };
>>>
>>> declare function map:empty()
>>> {
>>> function($x) { () }
>>> };
>>>
>>>
>>> let $map  := map:empty(),
>>> $map1 := map:entry($map,  1, ("one", "eins", "uno")),
>>> $map2 := map:entry($map1, 2, ("two", "zwei", "due"))
>>> return $map2(1)
>>
>> The execution of this script with BaseX 7.3 unexpectedly yields
>>
>> Stack Overflow: circular variable declaration?
>>
>> Note that replacing $map2(1) by $map1(1) in the last line returns
>> the expected result ("one", "eins", "uno").
>>
>> I'd be grateful for any comment/insight.
>>
>> Cheers and keep up the good work,
>> --Torsten
>>
>> --
>> | Prof. Dr. Torsten Grust
>> | Database Systems — Universität Tübingen (Germany)
>> | torsten.grust at uni-tuebingen.de
>> | db.inf.uni-tuebingen.de
>> _______________________________________________
>> BaseX-Talk mailing list
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-- 
| Prof. Dr. Torsten Grust
| Database Systems — Universität Tübingen (Germany)
| torsten.grust at uni-tuebingen.de
| db.inf.uni-tuebingen.de