Cast exception on recursion+map

On Wed, Oct 29, 2014 at 10:49 AM, Marco Lettere <marco.lettere at dedalus.eu> wrote: > Hello all, > I've stumbled upon an issue with the latest version and in particular the > code I provide was working with 8.0 snapshot up to build 496C381 and with > all previous official versions of course. Build 151df63 is the first build > I'm aware of the difference. > Shortly. In an input document I have a list of env nodes (sort of <env > name="n">v</env>). They need to be parsed and "xquery:eval(uated)" in > sequence because following env nodes may refer to preceding ones (i.e. <env > name="n1">v1</env>, <env name="n2">{$n1}</env>). > I've managed to do the job with the following code but now (as described in > the preamble) I get the following cast exception in the xquery:eval: > > Stopped at [...]/file, 9/31: ---> (this points to the line with the > xquery:eval call) > [XPTY0117] Cannot cast xs:untypedAtomic to xs:QName. > > I've absolutely no idea why it started giving this error and even looking at > the queryplan is too difficult in such a scenario for me. > Anyone can help me out? > > Thanks, > > This is the smallest example of the code I was able to produce: > > declare function local:declarations($env as map(*)){ > string-join( > map:keys($env) ! ( "declare variable $" || . || " external;") > ) > }; > > declare function local:updateenv($envnode as node(), $env){ > let $q := local:declarations($env) || serialize($envnode) > let $dynnode := xquery:eval($q, $env) > return > map:new(( > map:entry($envnode/data(@name), $dynnode/text()), > $env > )) > }; > > declare function local:buildenv($envnodes as node()*, $env as map(*)) { > if(empty($envnodes)) then $env > else > let $envnode := $envnodes[1] > let $newenv := local:updateenv($envnode, $env) > return map:new(( $newenv, local:buildenv($envnodes[position() > 1], > $newenv))) > }; > > map:serialize( > local:buildenv((<env name="n1">v1</env>, > <env name="n2">another {{$n1}}</env> > ), > map{}) > )

On 29/10/2014 11:44, Christian Grün wrote: > Hi Marco, > > this is a shorter version of the code that causes the error message: > > xquery:eval( > 'declare variable $x external; $x', > map { attribute a { 'x' }: 'x' } > ) > > It takes some more lines to explain what's going on, though: > > * The key of a map is being atomized. In the example, the attribute > will be converted to an item of type xs:untypedAtomic > * In earlier versions of the XQuery 3.1 Working Draft, all untyped > keys of a maps were cast to strings > * In a more recent version, map keys of type xs:untypedAtomic are not > cast anymore > * If xquery:eval is called, the untyped atomic cannot be cast to a QName ($x) > > The easiest solution is to replace "data(@name)" with "string(@name)". > I will additionally check if there is a clean way to do the cast > implicitly in BaseX. > > Hope this helps, > Christian > > [1] http://www.w3.org/TR/xquery-31/#doc-xquery31-MapConstructor > > > > On Wed, Oct 29, 2014 at 10:49 AM, Marco Lettere > <marco.lettere at dedalus.eu> wrote: >> Hello all, >> I've stumbled upon an issue with the latest version and in particular the >> code I provide was working with 8.0 snapshot up to build 496C381 and with >> all previous official versions of course. Build 151df63 is the first build >> I'm aware of the difference. >> Shortly. In an input document I have a list of env nodes (sort of <env >> name="n">v</env>). They need to be parsed and "xquery:eval(uated)" in >> sequence because following env nodes may refer to preceding ones (i.e. <env >> name="n1">v1</env>, <env name="n2">{$n1}</env>). >> I've managed to do the job with the following code but now (as described in >> the preamble) I get the following cast exception in the xquery:eval: >> >> Stopped at [...]/file, 9/31: ---> (this points to the line with the >> xquery:eval call) >> [XPTY0117] Cannot cast xs:untypedAtomic to xs:QName. >> >> I've absolutely no idea why it started giving this error and even looking at >> the queryplan is too difficult in such a scenario for me. >> Anyone can help me out? >> >> Thanks, >> >> This is the smallest example of the code I was able to produce: >> >> declare function local:declarations($env as map(*)){ >> string-join( >> map:keys($env) ! ( "declare variable $" || . || " external;") >> ) >> }; >> >> declare function local:updateenv($envnode as node(), $env){ >> let $q := local:declarations($env) || serialize($envnode) >> let $dynnode := xquery:eval($q, $env) >> return >> map:new(( >> map:entry($envnode/data(@name), $dynnode/text()), >> $env >> )) >> }; >> >> declare function local:buildenv($envnodes as node()*, $env as map(*)) { >> if(empty($envnodes)) then $env >> else >> let $envnode := $envnodes[1] >> let $newenv := local:updateenv($envnode, $env) >> return map:new(( $newenv, local:buildenv($envnodes[position() > 1], >> $newenv))) >> }; >> >> map:serialize( >> local:buildenv((<env name="n1">v1</env>, >> <env name="n2">another {{$n1}}</env> >> ), >> map{}) >> )

On Wed, Oct 29, 2014 at 12:18 PM, Marco Lettere <marco.lettere at dedalus.eu> wrote: > Wow, that was tricky! > Thanks a lot Christian and yes ... I'll pay defintely more attention to the > use of data()/string() in the future! > Cheers, > Marco. > > > On 29/10/2014 11:44, Christian Grün wrote: >> >> Hi Marco, >> >> this is a shorter version of the code that causes the error message: >> >> xquery:eval( >> 'declare variable $x external; $x', >> map { attribute a { 'x' }: 'x' } >> ) >> >> It takes some more lines to explain what's going on, though: >> >> * The key of a map is being atomized. In the example, the attribute >> will be converted to an item of type xs:untypedAtomic >> * In earlier versions of the XQuery 3.1 Working Draft, all untyped >> keys of a maps were cast to strings >> * In a more recent version, map keys of type xs:untypedAtomic are not >> cast anymore >> * If xquery:eval is called, the untyped atomic cannot be cast to a QName >> ($x) >> >> The easiest solution is to replace "data(@name)" with "string(@name)". >> I will additionally check if there is a clean way to do the cast >> implicitly in BaseX. >> >> Hope this helps, >> Christian >> >> [1] http://www.w3.org/TR/xquery-31/#doc-xquery31-MapConstructor >> >> >> >> On Wed, Oct 29, 2014 at 10:49 AM, Marco Lettere >> <marco.lettere at dedalus.eu> wrote: >>> >>> Hello all, >>> I've stumbled upon an issue with the latest version and in particular the >>> code I provide was working with 8.0 snapshot up to build 496C381 and with >>> all previous official versions of course. Build 151df63 is the first >>> build >>> I'm aware of the difference. >>> Shortly. In an input document I have a list of env nodes (sort of <env >>> name="n">v</env>). They need to be parsed and "xquery:eval(uated)" in >>> sequence because following env nodes may refer to preceding ones (i.e. >>> <env >>> name="n1">v1</env>, <env name="n2">{$n1}</env>). >>> I've managed to do the job with the following code but now (as described >>> in >>> the preamble) I get the following cast exception in the xquery:eval: >>> >>> Stopped at [...]/file, 9/31: ---> (this points to the line with the >>> xquery:eval call) >>> [XPTY0117] Cannot cast xs:untypedAtomic to xs:QName. >>> >>> I've absolutely no idea why it started giving this error and even looking >>> at >>> the queryplan is too difficult in such a scenario for me. >>> Anyone can help me out? >>> >>> Thanks, >>> >>> This is the smallest example of the code I was able to produce: >>> >>> declare function local:declarations($env as map(*)){ >>> string-join( >>> map:keys($env) ! ( "declare variable $" || . || " external;") >>> ) >>> }; >>> >>> declare function local:updateenv($envnode as node(), $env){ >>> let $q := local:declarations($env) || serialize($envnode) >>> let $dynnode := xquery:eval($q, $env) >>> return >>> map:new(( >>> map:entry($envnode/data(@name), $dynnode/text()), >>> $env >>> )) >>> }; >>> >>> declare function local:buildenv($envnodes as node()*, $env as map(*)) { >>> if(empty($envnodes)) then $env >>> else >>> let $envnode := $envnodes[1] >>> let $newenv := local:updateenv($envnode, $env) >>> return map:new(( $newenv, local:buildenv($envnodes[position() > 1], >>> $newenv))) >>> }; >>> >>> map:serialize( >>> local:buildenv((<env name="n1">v1</env>, >>> <env name="n2">another {{$n1}}</env> >>> ), >>> map{}) >>> ) > >