[rules-users] String range compares

[Edson Tirelli]

   Steve,

   Only way to do that today is through in-line eval().
   Although it is quite easy to add such support to drools, in case you want
to help providing us a patch. Probably 3-4 hours work. Just a matter of
adding the operator support in this class:

http://anonsvn.labs.jboss.com/labs/jbossrules/branches/4.0.x/drools-core/src/main/java/org/drools/base/evaluators/StringFactory.java

    And unit tests in this class:

http://anonsvn.labs.jboss.com/labs/jbossrules/branches/4.0.x/drools-core/src/test/java/org/drools/base/EvaluatorFactoryTest.java

   Everything else should work just fine and then your rules will be able to
use <, >, etc directly for String comparisons.

   []s
   Edson


2008/5/6 Steve Olson <SOlson at ameren.com>:

>
> We've hit a situation where the business users would like to specifiy some
> facts that have a range check (a 'between' type operation) on fixed length
> strings, that are usually short (6 characters or less).  Simple example -
> given a range of 'ABC' to 'ABM', this range would match all the character
> strings 'ABC', 'ABD', ..., 'ABM'.  We quickly discovered the '<' and '>'
> operators don't work with strings, and are wondering if others have solved
> this problem other ways.  Searches have shown some discussions about being
> able to build something like a custom StringEvaluator that does support
> '<'
> and '>', but we haven't seen enough to know what would be the best path.
>  If
> anyone has suggestions, other than using eval() for all such checks, I'd
> appreciate any info.
>
> Thanks in advance...
> --
> View this message in context:
> http://www.nabble.com/String-range-compares-tp17085898p17085898.html
> Sent from the drools - user mailing list archive at Nabble.com.
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>



-- 
Edson Tirelli
JBoss Drools Core Development
Office: +55 11 3529-6000
Mobile: +55 11 9287-5646
JBoss, a division of Red Hat @ www.jboss.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20080506/dc47f39a/attachment.html