Found problems with map:for-each

On Mon, Feb 19, 2024 at 4:51 PM Vincenzo Cestone <v.cestone at gmail.com> wrote: > Hi all, > > with the basex 10.7 version (but even in 9.6 version I have the same > issue) I found that the following code wont work as expected: > (: It wont work :) > let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), > "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} > let $w := map:for-each($files, function($filename, $content) { > file:write-binary($filename, $content, 0) > }) > return () > > that is, it will not write the two files hello1.txt and hello2.txt in the > basex_home/bin folder. > > But, if you return $w instead: > (: It works :) > let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), > "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} > let $w := map:for-each($files, function($filename, $content) { > file:write-binary($filename, $content, 0) > }) > return $w > > With a similar implementation, with the classic FLWOR, the issue does not > arise, even if I return the empty sequence: > (: It works :) > let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), > "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} > let $w := for $filename in map:keys($files) > return file:write-binary($filename, map:get($files, $filename), 0) > return () > > that is it will write two files hello1.txt and hello2.txt in > basex_home/bin folder. > > Note that the files in the examples above are for demonstration purposes, > however in my code they are actually binary files. > My java version is a Oracle JDK 17 > > This problem also occur to others? > > Thanks, > Vincenzo >

Il giorno lun 19 feb 2024 alle ore 19:20 Christian Grün < christian.gruen at gmail.com> ha scritto: > Hi Vincenzo, > > Thanks for your observation and the easily reproducible test case; we’ve > uploaded a new stable snapshot with a bug fix. > > Please note that it’s generally risky to explicitly return empty > sequences, as the optimizer will always try to get rid of code that may not > contribute to the final result (we try hard, though, to keep code alive > that has side effects, such as file:write-binary). In the given case, you > could simply rewrite your code as follows: > > let $files := map {"hello1.txt" : ... } > return map:for-each($files, function($filename, $content) { > file:write-binary($filename, $content, 0) > }) > > Ciao, > Christian > > [1] https://files.basex.org/releases/latest/ > > > > On Mon, Feb 19, 2024 at 4:51 PM Vincenzo Cestone <v.cestone at gmail.com> > wrote: > >> Hi all, >> >> with the basex 10.7 version (but even in 9.6 version I have the same >> issue) I found that the following code wont work as expected: >> (: It wont work :) >> let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), >> "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} >> let $w := map:for-each($files, function($filename, $content) { >> file:write-binary($filename, $content, 0) >> }) >> return () >> >> that is, it will not write the two files hello1.txt and hello2.txt in the >> basex_home/bin folder. >> >> But, if you return $w instead: >> (: It works :) >> let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), >> "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} >> let $w := map:for-each($files, function($filename, $content) { >> file:write-binary($filename, $content, 0) >> }) >> return $w >> >> With a similar implementation, with the classic FLWOR, the issue does not >> arise, even if I return the empty sequence: >> (: It works :) >> let $files := map {"hello1.txt" : xs:base64Binary('SGVsbG8gd29ybGQ='), >> "hello2.txt" : xs:base64Binary('SGVsbG8gd29ybGQ=')} >> let $w := for $filename in map:keys($files) >> return file:write-binary($filename, map:get($files, $filename), 0) >> return () >> >> that is it will write two files hello1.txt and hello2.txt in >> basex_home/bin folder. >> >> Note that the files in the examples above are for demonstration purposes, >> however in my code they are actually binary files. >> My java version is a Oracle JDK 17 >> >> This problem also occur to others? >> >> Thanks, >> Vincenzo >> >