Hi Johannes,

You’ve found a little bug that was introduced more than two years ago (a wrong static type was attached to the map constructor; we ignored the fact that a map lookup may yield an empty sequence). A new snapshot is available [1,2].

Thanks for the report, Christian

[1] https://github.com/BaseXdb/basex/issues/1766 [2] http://files.basex.org/releases/latest/

On Fri, Dec 6, 2019 at 5:18 PM Johannes Echterhoff echterhoff@interactive-instruments.de wrote:

All,

The following query:

let $lookupSequence := ('a','b')

let $map := map {'c': 'x'}

let $mapLookupEvaluation := $map?($lookupSequence)

return

(

'Evaluation of the map lookup is: ' || string-join($mapLookupEvaluation,", "),

'count($mapLookupEvaluation) is: ' || count($mapLookupEvaluation)

)

Results in:

Evaluation of the map lookup is:

count($mapLookupEvaluation) is: 2

I would have expected 0 instead of 2. Am I missing something?

Best regards,

Johannes