Re: [rules-users] Use of helper class to simulate "accumulate"

Jeevan, sorry, I missed your e-mail in the limbo. Just create a class or an attribute to be your accumulator... For instance, if you create a "branchCounter" attribute in the Tree object, you can do that: rule "Count branches" salience 10 when $t : Tree() Branch( tree == $t ) then $t.incrementBranchCounter(); modify( $t ); end rule "Check branch count" salience 0 when $t : Tree( branchCounter > 100 ) then // do something end The only trick is the salience. The first rule must have a higher salience in order to only fire the second rule after all branches are counted. Yes, in trunk you could do better with "accumulate" or "collect". For your case, "collect" would be simpler: rule "Check branches" when $t : Tree() $branches : ArrayList( size > 100 ) from collect( Branch( tree == $t ) ) then // do something end []s Edson Jeevan Tambuluri wrote: > Hello all, > > I have been told that you could implement a helper class to simulate > "accumulate" command in drools. Could you please ealborate on how to > do this? Some code snippet to illustrate this would be very much > appreciated. > > My problem is as follows.I have two types of facts - Tree and > Branch. Each Branch object has a reference to the Tree object it > belongs to. I want to write a rule: The number of branches in a tree > must not exceed 100. I guess this would be easy to write with > "accumulate" command, which is not yet available in 3.0.x. > > Thanks > > Jeevan > > ------------------------------------------------------------------------ > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > >