[rules-users] Convert logic to DRL rules
Edson Tirelli
tirelli at post.com
Mon Feb 19 14:40:33 EST 2007
Bill,
The new version works fine with nested conditional elements and allow
for any level of nesting. You simply must be very careful with OR as the
semantics of OR in a rules engine are not exactly the same as most
people are used to in imperative programming.
Also, the syntax you showed bellow is not correct (but maybe it was
simply a typo in the e-mail).
Maybe if you can write your "intent" or a sample rule (in english)
you are trying to implement it is easier to help.
[]s
Edson
Bill Zhang wrote:
> Edson,
>
> Thanks for the reply. The rule you authored worked fine on my new
> Drools build from SVN.
>
> However, I did notice that the following pattern matching is not working:
>
> $p: Person(
> (Person(some comparison logic) or Person(some comparison logic) )
> and
> (Person(some comparison logic) or Person(some comparison logic) )
> )
>
> Looks like althugh "or" is allowed, the new version does not use "and"
> within pattern matching. Am I right or did I do something wrong?
>
> Thanks,
>
> Bill
>
> On 2/19/07, Edson Tirelli <tirelli at post.com> wrote:
>
>> Bill,
>>
>> Unfortunatelly we are working hard to get all features finished in
>> time for the release and the documentation will only be done right
>> before release unless we get some help from community. So, maybe if you
>> (or anyone else) think you can help with that, we would gladly provide
>> you with info that when written down would be usefull both for your
>> users/team and to other drools users.
>>
>> You need to use bound variables when you want to do an OR (||)
>> between constraints of different fields inside a single Pattern. So, in
>> your example, as you want to do:
>>
>> lastOrderPrice > 300 OR totalOrderNumber >2
>>
>> For the same Person object, it means you need to do either:
>>
>> Person( $lop: lastOrderPrice, $ton: totalOrderNumber, ( $lop > 300 ||
>> $ton >2 ))
>>
>> Or using a predicate without the bound variables:
>>
>> $p: Person( ($p.getLastOrderPrice() > 300 || $p.getTotalOrderNumber() >
>> 2 ) )
>>
>> Or use an eval (that I think is the least efficient way):
>>
>> $p: Person()
>> eval( $p.getLastOrderPrice() > 300 || $p.getTotalOrderNumber() > 2 )
>>
>> From the above options, I would go with the first.
>> Unfortunatelly, there is no semantics currently defined for the
>> syntax you used:
>>
>> Person( lastOrderPrice > 300 || totalOrderNumber >2 )
>>
>> We may eventually do it in the future, but for now (Mark can confirm
>> that), we don't have resources to add it to the next major release
>> (again, unless community comes in to help).
>>
>> []s
>> Edson
>>
>>
>>
>>
>> Bill Zhang wrote:
>>
>> > That's it, Edson. I'll give it a try and I'll let you know whether I
>> > make it.
>> >
>> > Edson, I will appreciate if you can point to me where is the most
>> > recent syntax document. Thanks.
>> >
>> > I am not sure why I need to use bound variables ($lop:
>> > lastOrderPrice). Can I write it in the following:
>> >
>> > rule ...
>> > when
>> > $person : ( Person( age > 35 | <25,
>> > zipCode == "23546" | == "68570",
>> > ( lastOrderPrice > 300 ||
>> > totalOrderNumber >2 ))
>> > or
>> > Person( lastOrderCategory == "098" | == "109",
>> > zipCode == "74567" | == "23756" ) )
>> > then
>> > $person.setStatus( "KT" );
>> > end
>> >
>> >
>> >
>> > Thanks to everyone helping me. This is really a great community.
>> >
>> > On 2/19/07, Edson Tirelli <tirelli at post.com> wrote:
>> >
>> >>
>> >> Bill,
>> >>
>> >> Your statement bellow can be written in 3.1M1 as:
>> >>
>> >> rule ...
>> >> when
>> >> $person : ( Person( age > 35 | <25,
>> >> zipCode == "23546" | == "68570",
>> >> $lop: lastOrderPrice,
>> >> $ton: totalOrderNumber,
>> >> ( $lop > 300 || $ton >2 ))
>> >> or
>> >> Person( lastOrderCategory == "098" | == "109",
>> >> zipCode == "74567" | == "23756" ) )
>> >> then
>> >> $person.setStatus( "KT" );
>> >> end
>> >>
>> >> []s
>> >> Edson
>> >>
>> >> Bill Zhang wrote:
>> >>
>> >> > Hi Alex,
>> >> >
>> >> > Thank you for confirming this. Writing such a builder may take us a
>> >> > lot of time because our business user is used to free style
>> >> > Pascal-like authoring using quite complex logic. For example,
>> >> >
>> >> > IF
>> >> > (
>> >> > (
>> >> > (Person.Age > 35 OR Person.Age < 25) AND
>> >> > (Person.ZipCode =23546 or Person.ZipCode = 68590)
>> >> > )
>> >> > and
>> >> > (
>> >> > (Person.LastOrderPrice > 300 OR
>> >> > (Person.TotalOrderNumber > 2)
>> >> > )
>> >> > )
>> >> > OR
>> >> > (
>> >> > (
>> >> > (Person.LastOrderCategory in ("098", "109") ) AND
>> >> > (Person.ZipCode =74567 or Person.ZipCode = 23765)
>> >> > )
>> >> > and
>> >> > (
>> >> > (Person.LastOrderPrice > 1000 OR
>> >> > (Person.TotalOrderNumber > 1)
>> >> > )
>> >> > )
>> >> > ...
>> >> >
>> >> > THEN Person.Status = "KT";
>> >> >
>> >> > Before I set out to write the builder, I would like to know whether
>> >> > the new syntax can handle the above logic? Also, where can I find
>> >> > document for the new syntax?
>> >> >
>> >> > I am also trying to find some existing open source Java library to
>> >> > "flatten out" these complex logic - to break these complex logic to
>> >> > atomic ones that can be handled by Drools. Do you have any
>> >> > recommendation?
>> >> >
>> >> > Thanks a lot for your help.
>> >> >
>> >> > Bill Y.
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > On 2/19/07, Alexander Varakin <avarakin at optonline.net> wrote:
>> >> >
>> >> >> We built a Rule Builder which creates drl with all possible
>> >> >> combinations. In any case, drl syntax is not exactly business user
>> >> >> friendly, so having such builder is not a bad idea.
>> >> >> Simple Rule Builder can be implemented as an Excel spreadsheet,
>> which
>> >> >> can be easily parsed using POI library and then drl file produced.
>> >> >>
>> >> >> Steven Williams wrote:
>> >> >> > Hi Bill,
>> >> >> >
>> >> >> > To implement your rules in 3.0.5 you would need to implement
>> a rule
>> >> >> > for each combination of age and zipCode.
>> >> >> >
>> >> >> > $a : Person(age > 35 zipCode == 23546)
>> >> >> > then
>> >> >> > $a.setStatus("KT");
>> >> >> >
>> >> >> > $a : Person(age < 25, zipCode == 23546 )
>> >> >> > then
>> >> >> > $a.setStatus("KT");
>> >> >> >
>> >> >> > $a : Person(age > 35, zipCode == 68590)
>> >> >> > then
>> >> >> > $a.setStatus("KT");
>> >> >> >
>> >> >> > etc..
>> >> >> >
>> >> >> > Steve
>> >> >> >
>> >> >> > On 2/19/07, *Bill Zhang* <billzhang2006 at gmail.com
>> >> >> > <mailto:billzhang2006 at gmail.com>> wrote:
>> >> >> >
>> >> >> > So Alex, if I only want to use the old syntax that is in
>> >> >> production,
>> >> >> > there is no way to implement my seemingly simple logic
>> >> >> conditioning?
>> >> >> >
>> >> >> > Thanks for your help.
>> >> >> >
>> >> >> > On 2/18/07, Alexander Varakin < avarakin at optonline.net
>> >> >> > <mailto:avarakin at optonline.net>> wrote:
>> >> >> > > As far as I know this syntax is new and is available in
>> SVN
>> >> >> > only, you
>> >> >> > > will have to wait till 3.1 is released or take source from
>> >> SVN
>> >> >> > and build it.
>> >> >> > >
>> >> >> > > Bill Zhang wrote:
>> >> >> > > > Hi Steven,
>> >> >> > > >
>> >> >> > > > Thank you very much for your help. Really appreciate.
>> >> >> > > >
>> >> >> > > > I still got the same error, Unexpected token '|'. I
>> did not
>> >> >> > see "|" in
>> >> >> > > > the document, only saw "||", which is supposed to be
>> >> used with
>> >> >> > > > columns.
>> >> >> > > >
>> >> >> > > > Ye
>> >> >> > > >
>> >> >> > > > On 2/18/07, Steven Williams <
>> >> stevenw at objectconsulting.com.au
>> >> >> > <mailto:stevenw at objectconsulting.com.au>> wrote:
>> >> >> > > >> Hi Bill,
>> >> >> > > >>
>> >> >> > > >> I think it should be:
>> >> >> > > >>
>> >> >> > > >> $a : Person(age > 35 | < 25, zipCode == 23546 | ==
>> 68590)
>> >> >> > > >>
>> >> >> > > >> Edson, Mark or Michael can probably confirm or
>> correct the
>> >> >> > above syntax.
>> >> >> > > >>
>> >> >> > > >> Make sure you are running of the latest trunk.
>> >> >> > > >>
>> >> >> > > >> cheers
>> >> >> > > >> Steve
>> >> >> > > >>
>> >> >> > > >>
>> >> >> > > >> On 2/18/07, Bill Zhang <billzhang2006 at gmail.com
>> >> >> > <mailto:billzhang2006 at gmail.com>> wrote:
>> >> >> > > >> >
>> >> >> > > >> > I tried:
>> >> >> > > >> >
>> >> >> > > >> > $a : Person(age > 35 || age < 25, zipCode == 23546
>> || ==
>> >> >> 68590)
>> >> >> > > >> >
>> >> >> > > >> > Errors:
>> >> >> > > >> > org.drools.rule.InvalidRulePackage : unknown:39:30
>> >> >> > > >> Unexpected token '||'
>> >> >> > > >> > unknown:39:40 mismatched token:
>> >> >> > > >> [@246,1040:1041='<=',<47>,39:40];
>> >> >> > > >> > expecting type '('
>> >> >> > > >> > unknown:39:92 mismatched token:
>> >> >> > > >> [@258,1092:1092='<',<46>,39:92];
>> >> >> > > >> > expecting type '('
>> >> >> > > >> >
>> >> >> > > >> > I also tried
>> >> >> > > >> >
>> >> >> > > >> > $a : Person(age > 35 | age < 25, zipCode == 23546
>> | ==
>> >> >> 68590)
>> >> >> > > >> >
>> >> >> > > >> > Pretty much the same error.
>> >> >> > > >> >
>> >> >> > > >> > Based on the document, "||" is only valid for
>> columns...
>> >> >> > > >> >
>> >> >> > > >> >
>> >> >> > > >> > On 2/17/07, Bill Zhang <billzhang2006 at gmail.com
>> >> >> > <mailto:billzhang2006 at gmail.com>> wrote:
>> >> >> > > >> > > Thank you Steve. But I got syntax error using the
>> >> >> following.
>> >> >> > > >> > >
>> >> >> > > >> > > On 2/17/07, Steven Williams
>> >> >> > <stevenw at objectconsulting.com.au
>> >> >> > <mailto:stevenw at objectconsulting.com.au>> wrote:
>> >> >> > > >> > > > In trunk I think you can use connective
>> constraints:
>> >> >> > > >> > > >
>> >> >> > > >> > > > $a : Person(age > 35 | < 25, zipCode == 23546
>> | ==
>> >> >> 68590)
>> >> >> > > >> > > > then
>> >> >> > > >> > > > $a.setStatus("KT");
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > > On 2/18/07, Bill Zhang < billzhang2006 at gmail.com
>> >> >> > <mailto:billzhang2006 at gmail.com>> wrote:
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > Hello,
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > I am a new Drools user trying to convert the
>> >> >> > following simple
>> >> >> > > >> logic
>> >> >> > > >> into
>> >> >> > > >> > > > DRL:
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > IF (Person.Age > 35 OR Person.Age < 25) AND
>> >> >> > (Person.ZipCode =
>> >> >> > > >> 23546
>> >> >> > > >> or
>> >> >> > > >> > > > > Person.ZipCode = 68590)
>> >> >> > > >> > > > > THEN
>> >> >> > > >> > > > > Person.Status = "KT";
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > I found that it is not easy to convert the
>> above
>> >> >> > logic into
>> >> >> > > >> ONE DRL
>> >> >> > > >> rule.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > I tried something like this
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > when
>> >> >> > > >> > > > > $a: Person(age>35) or Person (age<25)
>> >> >> > > >> > > > > $b: Person(Zipcode==23456) or Person
>> (ZipCode ==
>> >> >> 68590)
>> >> >> > > >> > > > > $c: $a and $b
>> >> >> > > >> > > > > Then
>> >> >> > > >> > > > > $c.setStatus("KT")
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > But looks like I can not use
>> >> >> > > >> > > > > $c: $a and $b
>> >> >> > > >> > > > > becaue in Drools, you can only bind variable to
>> >> >> > column, not
>> >> >> > > >> to other
>> >> >> > > >> > > > varaibles.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > Please advise how to do this. I would
>> imagine this
>> >> >> > should be
>> >> >> > > >> quite
>> >> >> > > >> > > > > simple, maybe I missed something quite obvious.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > I know that I can write custom Java method
>> to do
>> >> >> > this, but if
>> >> >> > > >> I do
>> >> >> > > >> > > > > that, I suppose I lose the power of RETEOO
>> pattern
>> >> >> > matching
>> >> >> > > >> (pattern
>> >> >> > > >> > > > resuing,
>> >> >> > > >> > > > > etc.). So I prefer not to do that.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > I also understand I can break the above logic
>> >> into 4
>> >> >> > rules
>> >> >> > > >> and that
>> >> >> > > >> > > > > would be quite easy, but our business user
>> is not
>> >> >> used to
>> >> >> > > >> think in
>> >> >> > > >> > > > > that way. Also, we have more complex logic than
>> >> the
>> >> >> > above. So
>> >> >> > > >> what I
>> >> >> > > >> > > > > want is to see if there is a way to convert
>> this
>> >> >> > > >> > > > > kind of logic in ONE DRL rule.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > Thanks in advance.
>> >> >> > > >> > > > >
>> >> >> > > >> > > > > Bill
>> >> >> > > >> > > > > _______________________________________________
>> >> >> > > >> > > > > rules-users mailing list
>> >> >> > > >> > > > > rules-users at lists.jboss.org
>> >> >> > <mailto:rules-users at lists.jboss.org>
>> >> >> > > >> > > > >
>> >> >> > > >> https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > > >> > > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > > > --
>> >> >> > > >> > > > Steven Williams
>> >> >> > > >> > > >
>> >> >> > > >> > > > Supervising Consultant
>> >> >> > > >> > > >
>> >> >> > > >> > > > Object Consulting
>> >> >> > > >> > > > Office: 8615 4500 Mob: 0439 898 668 Fax: 8615
>> 4501
>> >> >> > > >> > > > stevenw at objectconsulting.com.au
>> >> >> > <mailto:stevenw at objectconsulting.com.au>
>> >> >> > > >> > > > www.objectconsulting.com.au
>> >> >> > <http://www.objectconsulting.com.au>
>> >> >> > > >> > > >
>> >> >> > > >> > > > consulting | development | training | support
>> >> >> > > >> > > > our experience makes the difference
>> >> >> > > >> > > > _______________________________________________
>> >> >> > > >> > > > rules-users mailing list
>> >> >> > > >> > > > rules-users at lists.jboss.org
>> >> >> > <mailto:rules-users at lists.jboss.org>
>> >> >> > > >> > > >
>> https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > > >> > > >
>> >> >> > > >> > > >
>> >> >> > > >> > >
>> >> >> > > >> > _______________________________________________
>> >> >> > > >> > rules-users mailing list
>> >> >> > > >> > rules-users at lists.jboss.org
>> >> >> > <mailto:rules-users at lists.jboss.org>
>> >> >> > > >> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > > >> >
>> >> >> > > >>
>> >> >> > > >>
>> >> >> > > >>
>> >> >> > > >> --
>> >> >> > > >> Steven Williams
>> >> >> > > >>
>> >> >> > > >> Supervising Consultant
>> >> >> > > >>
>> >> >> > > >> Object Consulting
>> >> >> > > >> Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
>> >> >> > > >> stevenw at objectconsulting.com.au
>> >> >> > <mailto:stevenw at objectconsulting.com.au>
>> >> >> > > >> www.objectconsulting.com.au
>> >> >> <http://www.objectconsulting.com.au>
>> >> >> > > >>
>> >> >> > > >> consulting | development | training | support
>> >> >> > > >> our experience makes the difference
>> >> >> > > >> _______________________________________________
>> >> >> > > >> rules-users mailing list
>> >> >> > > >> rules-users at lists.jboss.org
>> >> >> <mailto:rules-users at lists.jboss.org>
>> >> >> > > >> https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > > >>
>> >> >> > > >>
>> >> >> > > > _______________________________________________
>> >> >> > > > rules-users mailing list
>> >> >> > > > rules-users at lists.jboss.org
>> >> >> <mailto:rules-users at lists.jboss.org>
>> >> >> > > > https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > <https://lists.jboss.org/mailman/listinfo/rules-users>
>> >> >> > > >
>> >> >> > >
>> >> >> > > _______________________________________________
>> >> >> > > rules-users mailing list
>> >> >> > > rules-users at lists.jboss.org
>> >> <mailto:rules-users at lists.jboss.org>
>> >> >> > > https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> > >
>> >> >> > _______________________________________________
>> >> >> > rules-users mailing list
>> >> >> > rules-users at lists.jboss.org
>> >> <mailto:rules-users at lists.jboss.org>
>> >> >> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> > --
>> >> >> > Steven Williams
>> >> >> >
>> >> >> > Supervising Consultant
>> >> >> >
>> >> >> > Object Consulting
>> >> >> > Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501
>> >> >> > stevenw at objectconsulting.com.au
>> >> >> <mailto:stevenw at objectconsulting.com.au>
>> >> >> > www.objectconsulting.com.au <http://www.objectconsulting.com.au>
>> >> >> >
>> >> >> > consulting | development | training | support
>> >> >> > our experience makes the difference
>> >> >> >
>> >> >>
>> >>
>> ------------------------------------------------------------------------
>> >> >> >
>> >> >> > _______________________________________________
>> >> >> > rules-users mailing list
>> >> >> > rules-users at lists.jboss.org
>> >> >> > https://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 list
>> >> > rules-users at lists.jboss.org
>> >> > https://lists.jboss.org/mailman/listinfo/rules-users
>> >> >
>> >>
>> >>
>> >> --
>> >> Edson Tirelli
>> >> Software Engineer - JBoss Rules Core Developer
>> >> Office: +55 11 3124-6000
>> >> Mobile: +55 11 9218-4151
>> >> JBoss, a division of Red Hat @ www.jboss.com
>> >>
>> >>
>> >> _______________________________________________
>> >> rules-users mailing list
>> >> rules-users at lists.jboss.org
>> >> https://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
>> >
>>
>>
>> --
>> Edson Tirelli
>> Software Engineer - JBoss Rules Core Developer
>> Office: +55 11 3124-6000
>> Mobile: +55 11 9218-4151
>> JBoss, a division of Red Hat @ www.jboss.com
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://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
>
--
Edson Tirelli
Software Engineer - JBoss Rules Core Developer
Office: +55 11 3124-6000
Mobile: +55 11 9218-4151
JBoss, a division of Red Hat @ www.jboss.com
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