[rules-users] Pattern matching

[Jai Vasanth]

The first case
rule "Remove smaller or non-overriden"
    dialect "java"
    when
        L : Response( $r : value && status != "override" )
        (Response(  value > $r ) or Response( status == "override"))
    then
        retract( L );
end


breaks down to

rule "Rule1"
    dialect "java"
    when
        L : Response( $r : value && status != "override" )
        Response(  value > $r )
    then
        retract( L );
end

and

rule "Rule2"
    dialect "java"
    when
        L : Response( $r : value && status != "override" )
        Response( status == "override")
    then
        retract( L );
end


I see that the first rule removes all objects with smaller values and the
second one removes all the ones that arent overridden if there exists an
object that has an override


What I dont understand is, why the second one doesnt have similar behaviour


rule "Remove smaller or non-overriden"
    dialect "java"
    when
        L : Response( $r : value && status != "override" )
        Response(  value > $r ||  status == "override" )
    then
        retract( L );
end

When this rule runs , it should start removing objects with smaller values
that are *not* overridden .  So if an overridden object exists finally we
will be left with 2  objects

Response( maxvalue, non override status ) and Response( somevalue,
"override" )

When the rule fires now  L will take on the first one and the the other
object will match the second one since it has an override even though value
<= $r . This L should be extracted and we should just be left with the
overridden object.

But  I still seem to be left with both the objects.


Jai



On Feb 7, 2008 1:45 PM, Mark Proctor <mproctor at codehaus.org> wrote:

>  Better still why don't you say why you think it's different. Remember
> 'or' results in two rules being generate, so write out those two rules
> separately and it might help you understand. The second one is just standard
> logic. And don't forget you'll get standard cross products here, i.e. A x
> B and B x A.
>
> Mark
>
> Jai Vasanth wrote:
>
> Here is the actual reason why I wanted to know the difference between
> those 2.
>
>
> rule "Remove smaller or non-overriden"
>     dialect "java"
>     when
>         L : Response( $r : value && status != "override" )
>         (Response(  value > $r ) or Response( status == "override"))
>     then
>         retract( L );
> end
>
> The above rule performs what I intended. It retains the Response with the
> largest value or it the one that has an override status (if one exists)
>
> But I am getting a different behaviour for this one
>
> rule "Remove smaller or non-overriden"
>     dialect "java"
>     when
>         L : Response( $r : value && status != "override" )
>         Response(  value > $r ||  status == "override" )
>     then
>         retract( L );
> end
>
> This rule seems to retain both the objects, the overriden and the largest
> value
>
> Could you explain to me how they are diffrent.
>
> Thanks
>
> Jai
>
>
> On Feb 6, 2008 4:30 PM, Mark Proctor <mproctor at codehaus.org> wrote:
>
> >  One is a field constraint disjointed connected the other is a
> > Conditional Element 'or'. Details of both are covered in the manual. Suffice
> > to say the first is like writting if ( stmt1.attrib1 == "X" ||
> > smt1.attrib1 == "Y" ) whil the ohte results in two separate rules, one
> > checking "X" and the other checking "Y", both rules can match and fire.
> >
> > Mark
> >
> > Jai Vasanth wrote:
> >
> >  Hi,
> >
> >  What is the difference between the following 2 statements
> >
> >
> > stmt1 : FactA( attrib1 == "X" ||  attrib1 =="Y")
> >
> >
> > stmt2: FactA( attrib1 =="X") or FactA(attrib1 =="Y")
> >
> >
> >
> > Thanks
> >
> > Jai
> >
> > ------------------------------
> >
> > _______________________________________________
> > rules-users mailing listrules-users at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
> >
> > _______________________________________________
> > rules-users mailing list
> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> >
> >
> ------------------------------
>
> _______________________________________________
> rules-users mailing listrules-users at lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-users
>
>
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20080207/731f103b/attachment.html