Hi Giuseppe,

thanks for checking. I double-checked again. The problem is even weirder now:

When using the console, I too get 2x true:

$ ./bin/basex "./webapp/array_test.xql"
true
true

When using the web server, I still get this:

$ curl localhost:8994/rest?run=array_test.xql
false
true

At first I thought there was some cache at work, preventing the update, but it doesn't seem to be the case. I can edit the XQL und both outputs change accordingly, but the first boolean is still different.

Best regards,
Sebastian

Hi Sebastian,

In my Basex 9.0.1 and 8.6.7 you get two "true". 

Best,

Giuseppe

Universität Leipzig
Institute of Computer Science, NLP
Augustusplatz 10
04109 Leipzig
Deutschland
E-mail: celano@informatik.uni-leipzig.de
E-mail: giuseppegacelano@gmail.com
Web site 1: http://www.dh.uni-leipzig.de/wo/team/
Web site 2: https://sites.google.com/site/giuseppegacelano/

On May 11, 2018, at 1:50 AM, Sebastian Zimmer <sebastian.zimmer@uni-koeln.de> wrote:

Hi,

I have this script where I use the lookup operator to perform a unary lookup:

xquery version "3.1";
declare namespace array = "http://www.w3.org/2005/xpath-functions/array";

let $array := []

return (
  empty($array!?*),   (: returns false :)
  empty(
    for $i in 1 to array:size($array)
    return $array($i)
  )                  (: returns true  :)
)

I'm curious that the first expression returns false even though it should be equivalent to the second expression, if I read the XQuery spec [1] right:

If the context item is an array:

If the KeySpecifier is a wildcard ("*"), the UnaryLookup operator is equivalent to the following expression:

for $k in 1 to array:size(.)
return .($k)

But maybe I'm missing something. I'd be glad if you could help.

Best regards,
Sebastian Zimmer

[1] https://www.w3.org/TR/2017/REC-xquery-31-20170321/#id-unary-lookup

--
Sebastian Zimmer
sebastian.zimmer@uni-koeln.de

<cceh-logo-cyan.png>

Cologne Center for eHumanities
DH Center at the University of Cologne
<twitter_logo.png>@CCeHum

--
Sebastian Zimmer
sebastian.zimmer@uni-koeln.de

Cologne Center for eHumanities
DH Center at the University of Cologne
@CCeHum