April 2019 - BaseX-Talk - mailman.uni-konstanz.de

Options for ft:search
by Sebastian Zimmer 15 Mar '21

15 Mar '21

Hi, I'd like to request a feature concerning the ft:search method: An `lserror` option that works exactly like the global option `LSERROR`. It would be nice if we could set the maximum Levenshtein distance specifically for each fuzzy search without having to adjust the global option. Another question on ft:search: Is there a reason why it doesn't have a `case` option just like ft:contains has one? Best regards, Sebastian

2 3

Feature Request: Save untitled, open scripts when exiting GUI
by Andreas Mixich 30 Jul '20

30 Jul '20

SublimeText has this nifty feature, that it saves all open tabs, even if the have no representation on the filesystem, so one can continue exactly, where one has left off. I find myself often to have several, unnamed, XQueries open, to test this concept, to compose that function, etc. It would be nice, if one could simply shut off and have them reopened next time without naming a file and saving each item in question. -- Minden jót, all the best, Alles Gute, Andreas Mixich

2 6

db:replace() in DBA resulting in duplicates
by Zimmel, Daniel 20 May '19

20 May '19

Hello, something has gone awry in my database after a db:replace(): query: db:open('DB','/path/file.xml')/base-uri() result: /DB/path/file.xml This is as expected. The result is the replaced file. But when I query: db:open('DB')/root[@id='id']/base-uri() result is a sequence: /DB/path/file.xml /DB/path/file.xml The first result is the file before the db:replace(), the second after. Can somebody explain why db:open() with path parameter is returning one result, but without parameter two results? Database statistics say there are indeed two documents. But when I export the database, only one gets exported. This happens with db:replace() on 9.2 from the DBA browser interface. When I use the same db:replace() XQuery on 9.2 with my local database, all is well (document gets replaced, no duplicates). Settings should be the default ones. Thanks, Daniel

3 8

A Tail Call, that runs (not) if different numeric values are being used as parameter
by Andreas Mixich 02 May '19

02 May '19

Hi, as far as I have understood, a tail call function must end with the call to itself, after it has calculated all the values and, upon recursive call, no operation must be open in the calling instance of the function. This is why the following case confuses me. The function, as shown, produces a stack overflow and I get the hint to do tail recursion. However, if I swap just the expressions (after 'then' and 'else') in lines 13 and 14, the function computes. Now I would have thought, that it would break, because I recurse within another function, that is still open ('concat()') and thus must return to the calling function after recursion, but, interestingly, the swap of the expressions after the 'then' and 'else' statements on lines 13 and 14 do not error out with a stack overflow, in spite 'concat()' still being open. Both cases produce an integer. Also, advice would be welcome, on how I can solve this. Thank you very much. 1 declare function local:word-wrap( 2 $string as xs:string, 3 $width as xs:integer) 4 5 { 6 let $t := normalize-space($string) 7 return 8 if (string-length($t) < $width or string-length($t) = $width) 9 then $t 10 else 11 let $idx := 12 if (matches($t, "\s")) 13 then functx:index-of-string-last(substring($t, $width), " ") 14 else $width 15 return 16 concat( 17 string:trim-right(substring($t, 1, $idx)), 18 out:nl(), 19 local:word-wrap(string:trim-left(substring($t, $idx)),$width) 20 ) 21 }; 22 23 local:word-wrap("This is a very long line of text. It goes well beyond 80 (eighty) characters in width. Therefore we need a word wrap function, which we test in here. Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim ve iam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.",80) -- Minden jót, all the best, Alles Gute, Andreas Mixich

4 5

Java binding - variable arguments
by Luan Bui 23 Apr '19

23 Apr '19

Hello all, How can I call a method with variable arguments in BaseX with Java binding? I am trying to do this: |let $string := 'Format string: %1$d - %2$s'|| || let $i := 1|| || let $j := 'text'|| || return Q{java.lang.String}format·java.lang.String·java.lang.Object*($string, $string, $i, $j)| However, I got the error: [XPDY0002] {java.lang.String}format·java.lang.Stri...: Context is undeclared. Thank you for your time.

3 4

Query profiling and debugging support in BaseX
by Reece Dunn 22 Apr '19

22 Apr '19

Hi, I'm wondering how you would go about profiling a query in BaseX to determine how long various query statements take, so you can look at the places where you need to modify the query to be faster. I have added MarkLogic's profiling support into my XQuery plugin that does this and am wondering how this can be done in BaseX. I'm aware of the prof functions, but these are more useful for manually instrumenting sections of a query, and not an automated way of getting the timing information for all the queries and parts of the query. Specifically for integrating into an IDE. I could display the timings, like in the BaseX GUI. Is there a way to get this information using the org.basex.api.client interfaces? Is there a way to get the query plan, pre-evaluation mapping, and optimized query for the given query? It would be helpful to link these back to the source file, so things like optimisation hints can link back to the file being edited. Finally, I am looking into debugging support and am wondering if this is possible to do for BaseX queries. What approach would be best for this, especially in terms of integrating it into an IDE? Kind regards, Reece

2 8

RESTXQ, multipart/form-data, out of memory saving to file
by James Ball 21 Apr '19

21 Apr '19

Hello everyone, I’m trying to use BaseX RESTXQ to upload some large (around 300MB) Zip files using HTML forms (multipart/form-data), save them to disk and then process them. But I am getting server errors with large files (small files work perfectly). HTTP ERROR 500 Problem accessing /test.htm. Reason: Server Error Caused by: java.lang.OutOfMemoryError: Java heap space Powered by Jetty:// 9.4.9.v20180320 <http://eclipse.org/jetty> It seems to be when reading the file from the map of files. 1) Upload large file but do nothing with it - WORKS 2) Upload large file and just write the whole POST data to file - WORKS 3) Upload large file and write file from map - ERROR This is the file writing function I’m using: file:write-binary( "/Users/me/Desktop/delete2.zip”, $files(map:keys($files)[1]) ) Running BaseX 9.1 Is there something really obvious that I’m doing wrong? (There usually is :) ) Many thanks, James

3 6

map:merge() does not handle wrong $option parameter
by Andreas Mixich 21 Apr '19

21 Apr '19

Given: let $d1 := map {"key1":"value1"} let $d2 := map {"key2":"value2"} return map:merge($d1, $d2) where the two maps to be merged should have been included as sequence, but were, mistakenly, not, the function should return an error, since the second map gets evaluated as $options, but none of the $options are to be found inside. It seems, that only a type-check is done, to assure valid $options, since, in another case, I got a [XPTY0004]. -- Minden jót, all the best, Alles Gute, Andreas Mixich

2 1

Can't locate reason for a [XQST0049] Duplicate declaration of static variable
by Andreas Mixich 20 Apr '19

20 Apr '19

Hi, I get a `[XQST0049] Duplicate declaration of static variable $string:debug` and can't find out why. I checked the sources and the variable is declared only once. This happens in a scenario, where I have a co-dependency on several modules and each load the modules they need, some load the same modules as another module. I thought about a circular dependency, but I do not find it. Could it be made so, that upon such an error, the places, in which the 'other' declaration was found get referenced as well in the error message? That would be very practical (I also had problems like this with function declarations, in the past, some are still unresolved). Thanks, and congrats to the 9.2 update. -- Goody Bye, Minden jót, Mit freundlichen Grüßen, Andreas Mixich

2 2

java.lang.NullPointerException at org.basex.query.expr.TypeswitchGroup.equals(TypeswitchGroup.java:173)
by Andreas Mixich 19 Apr '19

19 Apr '19

Hello, I don't really understand what just happened, so I attached the testcase and stacktrace to circumvent any malformation by the mail software in use. -- Goody Bye, Minden jót, Mit freundlichen Grüßen, Andreas Mixich

2 3