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5268 discussions

Re: [basex-talk] an Earley parser in XQuery?
by C. M. Sperberg-McQueen 24 Aug '22

24 Aug '22

On 23 August 2022, Graydon Saunders wrote: > On Mon, Aug 22, 2022 at 07:42:39PM +0200, Martin Honnen scripsit: > > On 22.08.2022 19:07, Graydon Saunders wrote: > > > I'm trying to test if some extracted sentences validate as productions > > > of a particular context-free grammar expressed in a BNF dialect. > > > > > > Is there an available implementation of a parser in XQuery that can do > > > this? > > > > > In the context of Invisible XML https://invisiblexml.org/ I have heard > > that term "Earley" parser a lot but I am not familiar enough with the > > various implementations to tell whether all are "Earley" parsers, > > https://github.com/cmsmcq/Aparecium is an XQuery implementation of > > Invisible XML. For what it's worth: Of the ixml processors I'm familiar with, all use (or can use) Earley parsers to parse the input string against the input grammar; Norm Walsh's Coffeepot and its related libraries also make a GLL parser available, which is sometimes faster and sometimes slower. About half use the same parser to parse the input grammar against the spec grammar; about half have a hand-written parser for the ixml spec grammar. > And thus interesting, but alas too slow for the application I have. If you are willing and able to send me a copy of your grammar and some sample data, I would be grateful; it might help me improve the situation with respect to Aparecium's performance. Both Norm Walsh's processor and John Lumley's processor are currently a lot faster than Aparecium, though I don't know a simple way to call them directly from XQuery. Another alternative, if you have speed issues and just one grammar you are interested in, is to use Gunther Rademacher's REx parser generator to compile the grammar you are interested in into a parser written in XQuery (other target languages are also available). https://bottlecaps.de/rex/ -- C. M. Sperberg-McQueen Black Mesa Technologies LLC http://blackmesatech.com

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an Earley parser in XQuery?
by Graydon Saunders 23 Aug '22

23 Aug '22

Hello -- I'm trying to test if some extracted sentences validate as productions of a particular context-free grammar expressed in a BNF dialect. Is there an available implementation of a parser in XQuery that can do this? Thanks! Graydon

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Very niche question about BaseX 9.5.1 and java bindings
by Andy Bunce 22 Aug '22

22 Aug '22

Hi, I am trying to write a Java property file using v9.5.1 and no new Java code. The code below runs in 9.7.3. Although it only uses 9.5 features in 9.5.1 it produces the error message props:store·java.io.Writer·String cannot be called with (Writer, String). but https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html#store-j… I assume this is a 9.5.1 java binding bug? Any workaround suggestions or details of what the problem is? /Andy ----------------------------------------------- (:~ Using Basex 9.5.1 and assuming a file "test.properties" in folder containing this module:) import module namespace props = "java:java.util.Properties"; declare variable $source:= file:resolve-path("test.properties",file:base-dir()) !(prof:void(props:load·java.io.Reader(Q{java:java.io.FileReader}new(.))),.) ; props:store·java.io.Writer·String( Q{java:java.io.FileWriter}new($source), "The saucer has landed")

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Basex 10.1, cannot execute query for a particular file name
by ykhabins＠bellsouth.net 19 Aug '22

19 Aug '22

Hello, Congrats on the release of BaseX 10.1 I decided to try XQuery 4.0 functionality right away. So, I typed a new query without saving it on the file system as follows: xquery version "4.0"; (1 to 5) -> {. + .} Executed it, and it is worked. I saved it as a file name: [xquery version 4.0] without square brackets. Extension is 0 And I cannot execute it anymore. Why is that? Just when I saved it as [xquery version 4.xq], I was able to execute it again. Just a peculiarity. Regards, Yitzhak Khabinsky

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Memory footprint for a certain query is much higher usisng BaseX10 compared to 9
by Alexander Witzigmann 16 Aug '22

16 Aug '22

Hi, BaseX 10 has a different behavior in memory footprint for the following situation. To avoid passing around data you can create db using the following create (i did this with BaseX 9) declare variable $input := <root><sheet name="SAP">{for $idx in (1 to 10000) return <row>{for $e in $enames return element {$e} { attribute {"content"} {$idx}}}</row>}</sheet></root>; db:create("test-db",$input,"test.xml") Then using the following query on the created db: declare variable $input := db:open("test-db"); <root>{ for $s in $input//sheet[./@name => contains("SAP")] return <sheet>{$s/@*}{ for $r in $s//row let $no := $r/Objektkurztext/@content return <row>{$r/@*}{($r/*,<partno>{$no}</partno>)}</row> }</sheet> }</root> Using BaseX 9 the used memory for the query is round about 2 GB which is ok. Using BaseX 10 Out-of-Memory exception happens in my case used memory is > 12 GB Any thoughts what the reason is - any additional information required? Alex

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New fails without warning when one file out of 27 is locked
by Patrick Durusau 15 Aug '22

15 Aug '22

Greetings! My mistake but I had one file out of 27 open in an editor when I tried to create a new database across the file set. Got the error message that basex 10.0 could not find (file-name), so I chose ok. Apparently basex failed at that point and did not skip the open file. No database was created. Not a problem because I closed the file and re-ran new but curious if that is the expected behavior? Or should it skip the locked file? Thanks for all the hard work! Patrick -- Patrick Durusau patrick(a)durusau.net Technical Advisory Board, OASIS (TAB) Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300 Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps) Another Word For It (blog): http://tm.durusau.net Homepage: http://www.durusau.net Twitter: patrickDurusau

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Convert base64 to XML
by ykhabins＠bellsouth.net 15 Aug '22

15 Aug '22

Hello, I am calling a SOAP Web Service via http:send-request(...) method. It returns back base64 encoded XML. Here is how I am converting it into XML: return html:parse(convert:binary-to-string(xs:base64Binary(http:send-request(...))) ) So, I am using three function/method calls: - xs:base64Binary() - convert:binary-to-string() - html:parse() Is there a more straight forward method to convert base64 encoded string to XML in the BaseX 10.0? Regards, Yitzhak Khabinsky

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List of functions created in xquery:eval-update show unexpected behavior
by Wiemer, Sebastian 15 Aug '22

15 Aug '22

Hi, I ran over an unexpected bahavior of BaseX 9.7.3 Can anyone explain? Note: BaseX 9.7.3 is running with MIXUPDATES=true file1.xq: create to functions in a list and call each function with a list comprehension ---- declare function local:bla(){<bla id=""/> }; declare function local:blubb(){<blubb id=""/> }; (local:bla#0,local:blubb#0)!.() ---- Result: as expected <bla id=""/> <blubb id=""/> file2.xq: same as above, but in an xquery:eval --- xquery:eval( ' declare function local:bla(){<bla id=""/>}; declare function local:blubb(){<blubb id=""/> }; local:bla#0,local:blubb#0 ' )!.() --- Result: as expected <bla id=""/> <blubb id=""/> file3.xq: same as file1, but with a little "twist" --- declare function local:bla(){<bla/> update {insert node attribute id {} into .}}; declare function local:blubb(){<blubb/> update {insert node attribute id {} into .}}; (local:bla#0,local:blubb#0)!.() --- Result: as expected <bla id=""/> <blubb id=""/> file4.xq trying to call the same with xquery:eval will not work ([xquery:update] No updating expression allowed.), so we use xquery:eval-update() --- xquery:eval-update( ' declare function local:bla(){<bla/> update insert node attribute id {} into .}; declare function local:blubb(){<blubb/> update insert node attribute id {} into .}; local:bla#0,local:blubb#0 ' )!.() -- Result: expected <bla id=""/> <blubb id=""/> But the result is: local:bla#0 local:blubb#0 file5.xq: --- xquery:eval-update( ' declare function local:bla(){<bla/> update insert node attribute id {} into .}; declare function local:blubb(){<blubb/> update insert node attribute id {} into .}; local:bla#0 ' )() --- Result: as expected <bla id=""/> Is this a bug? A for-loop will not work either. Best regards, Sebastian IT-Tacheles – IT-Themen auf den Punkt Folge 38: Datenplattformen https://www.adesso.de/de/news/it-tacheles/folge-38.jsp?pk_campaign=ittachel… ------------------------------------------------------- >>> business. people. technology. <<< ------------------------------------------------------- adesso SE mit Sitz in Dortmund Vorstand: Michael Kenfenheuer (Vors.), Dirk Pothen, Andreas Prenneis, Stefan Riedel, Jörg Schroeder, Torsten Wegener Vorsitzender des Aufsichtsrates: Prof. Dr. Volker Gruhn Amtsgericht Dortmund HRB 20663

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Error messages in Basex 9.7.x
by Marc Coenegracht 14 Aug '22

14 Aug '22

Hello Christian, In a clean install of Debian 11, openjdk version "11.0.16" 2022-07-19, I unzipped BaseX973.zip and started the the HTTP server with: basexhttp -S (with debugging set to true). The following error-message appeared: java.lang.IllegalThreadStateException: process hasn't exited at java.base/java.lang.ProcessImpl.exitValue(ProcessImpl.java:521) at org.basex.util.Util.error(Util.java:311) at org.basex.BaseXHTTP.start(BaseXHTTP.java:301) at org.basex.BaseXHTTP.<init>(BaseXHTTP.java:125) at org.basex.BaseXHTTP.main(BaseXHTTP.java:54) which is repeated 10 times (all messages are exactly identical) If the server gets started with: 'basexhttp &' all is fine, no errors. The server starts up normally after these errors and it can be shut down cleanly again. In a few of my scripts the following errors pops up: Creating Database... java.lang.ClassNotFoundException: com.sun.org.apache.xerces.internal.util.XMLCatalogResolver at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at ... etc (multiple classes, long list) Creating Database... .java.lang.NumberFormatException: For input string: "E" at java.base/jdk.internal.math.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2054) at ... etc repeated twice. The errors are seemingly without consequence, all is functioning fine and the created databases seem OK. Actually the only reason I noticed the errors is because I made the foolish decision to set debugging to true ... :) I tested versions 9.7 and 9.7.3 on multiple Debian 11 boxes with openjdk 11.0.16, and version 9.7 in an older Debian 9 box with openjdk 11.0.6, results are identical. Best, Marc

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BaseX 10.0 as a SOAP client
by ykhabins＠bellsouth.net 12 Aug '22

12 Aug '22

Hello, I need to call SOAP Web Service based on its URL and WSDL. The Web Service is password protected, and returns back XML. WSDL shows all operations, aka methods. Is it possible to make calls to SOAP Web Service from the BaseX 10.0? Regards, Yitzhak Khabinsky

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