[rules-users] some pointers for solution

Greg Barton greg_barton at yahoo.com
Sun Nov 8 23:46:33 EST 2009 

Yeah,  That condition is just an optimization that prevents comparison of a Query against a Data that has less Criteria than the Query, which by definition cannot then be satisfied.  It's not logically necessary, but a pretty easy optimization.

--- On Sun, 11/8/09, Wishing Carebear <wishing.carebear at gmail.com> wrote:

> From: Wishing Carebear <wishing.carebear at gmail.com>
> Subject: Re: [rules-users] some pointers for solution
> To: "Rules Users List" <rules-users at lists.jboss.org>
> Date: Sunday, November 8, 2009, 10:33 PM
> Also I hope modifying the
> statement:
> q : Query( size <= d.size )
> to
> q : Query( )
> 
> should be fine.
>  
> 
>  
> 2009/11/8 Greg Barton <greg_barton at yahoo.com>
> 
> Yep.  See attached
> project.  It actually simplifies the java a bit, as now
> there doesn't need to be any trickery in the contains
> method for Query.  The rule now uses a from clause to get
> the Criteria directly from the Query:
> 
> 
> 
> rule "Match"
>  when
>    d : Data()
>    q : Query( size <= d.size )
>      $total : Number( intValue == q.size )
>        from accumulate( Criteria( this memberOf d )
> from q, count(1) )
> 
> 
>  then
>    System.out.println("Match: " + d + "
> and " + q) ;
> end
> 
> Try the other methods, though. (The eval
> 'hack' I included before, and Wolfgang's
> method.)  All of these approaches should have different
> performance behavior, and I honestly don't know which
> one is fastest.
> 
> 
> 
> --- On Sun, 11/8/09, Wishing Carebear <wishing.carebear at gmail.com>
> wrote:
> 
> > From: Wishing Carebear <wishing.carebear at gmail.com>
> 
> > Subject: Re: [rules-users] some pointers for solution
> > To: "Rules Users List" <rules-users at lists.jboss.org>
> > Date: Sunday, November 8, 2009, 8:02 PM
> 
> 
> > Yes Edson, I tried with count and
> sum.
> > Both seems to be working fine.
> >  
> > But with the test case, the Criteria for query also
> > needs to be inserted in addition to the query and
> data
> 
> > objects like shown below:
> >  
> > Query query = new Query(1);
> > query.add(new
> > Criteria(query, "c2", "bas"));
> > ksession.insert(query);
> > for(Criteria c :
> > query) {
> 
> > ksession.insert(c);
> > }
> >  
> >  
> > Is it possible to avoid them.
> >  
> > Thanks,
> > cabear
> >
> >
> >
> 
> 
> 
> > 2009/11/8 Edson Tirelli <ed.tirelli at gmail.com>
> >
> >
> >    Why not use count() accumulate function? ;)
> >
> >
> > from accumulate( Criteria( this memberOf d, this
> memberOf q
> 
> > ),
> >                           
> > count(1) )
> >
> >    Edson
> >
> >
> >
> >
> >
> > 2009/11/8 Greg Barton <greg_barton at yahoo.com>
> 
> >
> > In this case
> > the accumulate clause is maintaining a counter
> (total)
> > that's incremented whenever a Criteria is detected
> that
> > is contained in both the Data and Query object matched
> in
> 
> > the rule.  So:
> >
> >
> > # Find Criteria that are contained in both the Data
> and
> > Query
> >
> > from accumulate( Criteria( this memberOf d, this
> > memberOf q ),
> > # Initialize the counter to 0
> 
> >  init( int total = 0; ),
> > # Increment when the above condition is  matched
> >  action( total ++; ),
> > # Decrement if a matched Criteria now fails to match
> >
> >  reverse( total --; ),
> > # return the total when all known Criteria are
> matched
> 
> >  result( total ) )
> >
> >
> > --- On Sun, 11/8/09, Wishing Carebear <wishing.carebear at gmail.com>
> > wrote:
> >
> > > From: Wishing Carebear <wishing.carebear at gmail.com>
> 
> >
> > > Subject: Re: [rules-users] some pointers for
> > solution
> > > To: "Rules Users List" <rules-users at lists.jboss.org>
> > > Date: Sunday, November 8, 2009, 11:39 AM
> 
> >
> >
> >
> >
> > > Hi Greg:
> > > I'm trying to understand your first
> > > solution.
> > >  
> > > Ran the project and it works fine. If possible
> could
> > > you explain me little bit on :
> 
> > >
> > > from accumulate( Criteria( this memberOf d,
> >
> > > this memberOf q ),
> > > init( int total = 0; ),
> > > action( total ++; ),
> > > reverse( total --; ),
> > > result( total ) )
> 
> > >  
> > >  
> > > Thanks,
> > > cabear
> > >
> > >
> 
> 
> 
> > > 2009/11/8 Greg Barton <greg_barton at yahoo.com>
> >
> > >
> > > There are a couple of
> > > ways to do this.  I'm sure there's a bit
> more
> 
> > clean
> > > way than the example I'm providing, but this
> > should get
> > > you in the right direction.  It's not 100%
> > rules,
> >
> > > because it involves a bit of java collections
> 
> > trickery. (See
> > > attached project,
> > collection_DroolsCriteriaMatch.tar.gz)
> > >
> > >
> > > The heart of it is a single rule:
> > >
> > > rule "Match"
> 
> >
> > >  when
> > >    d : Data()
> > >    q : Query( size <= d.size )
> > >    Number( intValue == q.size )
> > >    from accumulate(
> > >      Criteria( this memberOf d, this memberOf
> q ),
> 
> > >
> > >      init( int total = 0; ),
> >
> > >      action( total ++; ),
> > >      reverse( total --; ),
> > >      result( total )
> > >    )
> > >  then
> > >    System.out.println("Match: " + d
> +
> 
> > "
> > > and " + q) ;
> > > end
> >
> > >
> > > The Data object holds data to be queried, Query
> > objects are
> > > asserted to match the Data, and Criteria objects
> can
> 
> > be
> > > contained in either. (With the aforementioned
> > collections
> > > trickery that if a Criteria is contained in a
> Query it
> > can
> >
> > > be found in a Data object, but the reverse
> isn't
> 
> > true.
> > >  See the Query.contains(Object) method for how
> > that's
> > > implemented.)
> > >
> > >
> > > So the rule above basically says
> "There's a
> > Data
> 
> >
> > > object, and all of the Query objects Criteria
> are
> > contained
> > > in the Data object."
> > >
> > > There's an alternate way of doing this using
> eval
> > and a
> 
> > > bit more java fu.  See the
> > eval_DroolsCriteriaMatch.tar.gz
> >
> > > project attached.  This one's probably not
> > optimal,
> > > though, as it's basically a brute force check
> of
> 
> > all
> > > Data objects against the asserted Query.
> > >
> > >
> > > I tried for a while to get a solution working
> with
> >
> > > different criteria types from both Data and
> Query
> 
> > objects
> > > being asserted into working memory, but I
> couldn't
> > get
> > > the accumulate syntax right.  Anyone know of a
> way to
> > do
> > > that? (I figure that would get a "pure
> 
> > rules"
> >
> > > solution.)
> > >
> > >
> > > --- On Sat, 11/7/09, Wishing Carebear <wishing.carebear at gmail.com>
> > > wrote:
> 
> > >
> > > > From: Wishing Carebear <wishing.carebear at gmail.com>
> >
> > >
> > > > Subject: [rules-users] some pointers for
> > solution
> 
> > > > To: rules-users at lists.jboss.org
> > > > Date: Saturday, November 7, 2009, 10:19 PM
> >
> > >
> > >
> > >
> 
> > > > Hello:
> > > > There are n selection criteria from s1 .. sn
> for
> > each
> > > > item i1.. in. Each item can have a subset
> of
> > criteria
> > > which
> 
> > > > applies to them.
> >
> > > >  
> > > > The end user, can choose a subset of
> criteria
> > like c1
> > >
> > > > and c5 and only the item that has c1 and c5
> > valid
> 
> > > should be
> > > > returned. For example: if item i1 and i2
> have
> >
> > > criterias
> > > > valid for c1, c2, c5, c6, c8 since the
> request is
> > only
> > > for
> > > > criteria c1 and c5, i1 and i2 must be
> returned.
> 
> > >
> > > >
> > > >  
> > > > Is it possible to write a rule using drools
> for
> > this
> >
> > > > requirement.
> > > >  
> > > > Thanks for your help and time,
> 
> > > > cabear
> > > >
> > > > -----Inline Attachment Follows-----
> 
> > >
> > > >
> > > >
> _______________________________________________
> >
> > > > 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
> 
> > >
> > >
> > >
> > >
> > >
> > > -----Inline Attachment Follows-----
> 
> >
> > >
> > > _______________________________________________
> > > 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
> >  JBoss Drools Core Development
> >  JBoss by Red Hat @ www.jboss.com
> >
> >
> > _______________________________________________
> 
> 
> > rules-users mailing list
> > rules-users at lists.jboss.org
> > https://lists.jboss.org/mailman/listinfo/rules-users
> 
> >
> >
> >
> >
> >
> > -----Inline Attachment Follows-----
> 
> 
> 
> >
> > _______________________________________________
> > 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
> 
> 
> 
> 
> 
> -----Inline Attachment Follows-----
> 
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>

More information about the rules-users mailing list