Re: [basex-talk] random:integer vs. random:seeded-integer - BaseX-Talk - mailman.uni-konstanz.de

19 Aug 2014


      Thanks, Christian!
Cheers,
Amanda
...
Date: Tue, 19 Aug 2014 16:04:17 +0200
From: Christian Gr?n christian.gruen@gmail.com
To: Dirk Kirsten dk@basex.org
Cc: BaseX basex-talk@mailman.uni-konstanz.de
Subject: Re: [basex-talk] random:integer vs. random:seeded-integer
Message-ID:
   <CAP94bnObngxdY3GmJABJYsxF8Bt4WJBcyFeQf-
3QwGfrPJzAOg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Hi Amanda,
I have extended Dirk's pull request and added new error codes [1]; a new
snapshot is available [2].
Best,
Christian
[1] http://docs.basex.org/wiki/Random_Module
[2] http://files.basex.org/releases/latest/
On Mon, Aug 18, 2014 at 5:10 PM, Dirk Kirsten dk@basex.org wrote:
...
Hello Amanda,
I agree, this behaviour is inconsistent. I am not quite sure what is
the best way to go here. Raising no error and simply returning 0 (as
it is currently done for random:integer() if max is out of range)
seems pretty dangerous to me, considering that randomness is often
used for security and an unexpected 0 might be hazardous.
Raising a Java error is maybe not the most elegant thing, maybe an
XQuery error would be more elegant (like FOAR0001, see
https://docs.basex.org/wiki/XQuery_Errors).
I created a small pull request, which also throws an error for
random:integer() if max is out of range, see
https://github.com/BaseXdb/basex/pull/985.
Cheers,
Dirk
On 18/08/14 15:56, Amanda Galtman wrote:
...
Hi,
Is it intentional that random:integer lets you use zero or a negative value
for $max, but random:seeded-integer errors out in those cases? I know
these are edge cases. I'm only flagging them because of the inconsistency
between the two similar functions.
...
...
(: Returns (0,0). :)
(random:integer(0),random:integer(-5))
(: Errors out :)
random:seeded-integer(31,1,0)
(: Errors out :)
random:seeded-integer(31,1,-5)
Here is the error information from the last command above.
Error:
Improper use? Potential bug? Your feedback is welcome:
Contact: basex-talk@mailman.uni-konstanz.de
Version: BaseX 7.9
Java: Oracle Corporation, 1.7.0_25
OS: Windows 7, amd64
Stack Trace:
java.lang.IllegalArgumentException: n must be positive
      at java.util.Random.nextInt(Unknown Source)
      at org.basex.query.func.FNRandom$1.next(FNRandom.java:85)
      at org.basex.query.MainModule$1.next(MainModule.java:98)
      at org.basex.query.QueryContext.execute(QueryContext.java:598)
      at org.basex.query.QueryProcessor.execute(QueryProcessor.java:101)
      at org.basex.core.cmd.AQuery.query(AQuery.java:82)
      at org.basex.core.cmd.XQuery.run(XQuery.java:22)
      at org.basex.core.Command.run(Command.java:329)
      at org.basex.core.Command.execute(Command.java:94)
      at org.basex.gui.GUI.exec(GUI.java:417)
      at org.basex.gui.GUI.access$500(GUI.java:41)
      at org.basex.gui.GUI$8.run(GUI.java:361)
Cheers,
Amanda
--
Dirk Kirsten, BaseX GmbH, http://basex.org
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