Re: [rules-users] Strategy for initializing objects

As an alternative, consider asserting a single Fact Shelf with field x initially 0. Then you could do rule "Another box on the shelf" when     b: Box( x == -1, $size : size )     s: Shelf( $x : x ) then     b.setX( $x ); update( b );     s.setX( $x + $size ); update( s ); end -W 2009/8/8 Greg Barton <greg_barton(a)yahoo.com&gt; > > You answer your own question.  Use accumulate: > > rule "Hello World" >        when >                b : Box( x == -1 ) >                newX : Integer() from accumulate( box: Box( x != -1 ), >                                  init( int i = 0; ), >                                  action( i += box.size; ), >                                  reverse( i -= box.size; ), >                                  result( i ) ) >        then >                System.out.println("Sum: " + newX); >                b.setX(newX); >                System.out.println(b); >                update(b); > end > > See attached project. > > --- On Sat, 8/8/09, sonia <robotnic+drools(a)gmail.com&gt; wrote: > > > From: sonia <robotnic+drools(a)gmail.com&gt; > > Subject: Re: [rules-users] Strategy for initializing objects > > To: "Rules Users List" <rules-users(a)lists.jboss.org&gt; > > Date: Saturday, August 8, 2009, 2:36 AM > > In general: I want to set a property > > in the Box objects, depending on > > all previously set objects.. > > > > My goal is to place the boxes one after another, for this I > > keep a > > variable in Box object. > > It seems like the easiest way to accumulate the sizes of > > boxes that > > are already placed. > > > > In the 'then' clause, I set the box location, and update > > the X by > > adding the size of the currently placed box. > > > > 2009/8/8 Wolfgang Laun <wolfgang.laun(a)gmail.com&gt;: > > > Your goal and the presented code aren't clear to me. > > The consequence (after > > > then) contains calls to static/class methods > > (Box.setX()) which isn't going > > > to change anything in your fact object. The call > > b.setX() might change your > > > object, but this depends on what the class method > > Box.getX() returns. > > > > > > Assuming Drools 5, a typical consequence would look > > like > > >    b: Box(...) > > > then > > >    modify( b ){ > > >       setX( ... ) > > >    } > > > end > > > > > > -W > > > > > > On Sat, Aug 8, 2009 at 1:48 AM, sonia <robotnic+drools(a)gmail.com&gt; > > wrote: > > >> > > >> Hello > > >> > > >> I want to achieve this: > > >> box1.setX(0) > > >> box2.setX(box1.size()); > > >> box2.setX(box1.size + box2.size) > > >> ... > > >> > > >> I want to do it with rules, and would like to know > > what's the best > > >> method of initializing (or any other operation > > with varying data) a > > >> group of objects > > >> > > >> rule "init box" > > >>  when > > >>   b : Box( x == -1) > > >>  then > > >>   b.setX(Box.getX()); > > >>   Box.setX( Box.getX() + b.size); > > >> end > > >> > > >> This does not work. > > >> A single box object is matched several times > > instead of different box > > >> objects. > > >> What is happening? how come a single box object is > > matched several > > >> times? Why doesnt drools choose other instances of > > box? > > >> > > >> What do I need to do to initialize all boxes, once > > for every box? > > >> > > >> Thank you. > > >> > > >> -- > > >> robosonia > > >> _______________________________________________ > > >> rules-users mailing list > > >> rules-users(a)lists.jboss.org > > >> https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > _______________________________________________ > > > rules-users mailing list > > > rules-users(a)lists.jboss.org > > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > > > > > > > > > -- > > robosonia > > > > _______________________________________________ > > rules-users mailing list > > rules-users(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users