Jeevan, You are right: the simplest way would be use "forall". Unfortunatelly it is only available in trunk. To do it in 3.0.x you will need either a helper attribute or a helper class. For instance, you may add a "branchLength" attribute to the tree and define 2 rules: rule "define length" when $t : Tree( branchLength == -1 ) Branch( mytree == $t, $bl : branch_length ) then $t.setBranchLength( $bl.intValue() ); modify( $t ); end rule "check length" when $t : Tree( $bl : branchLength != -1 ) exists Branch( mytree == $t, branch_length != $bl ) then // do something because the branch has a different length end There are several variations but you will need 2 rules to emulate this. Hopefully the new version will be out soon solving this kind of problem. []s Edson Jeevan Tambuluri wrote: > Hello all, > > I am looking for a way to define rules for the following problem: > > class Tree { > ... > } > > class Branch { > Tree mytree; > int branch_length; > ... > } > > Let's say I have a fact called Tree and another fact called Branch. > Brach identifies which tree it belongs to. > Now, I want to write a rule to say that all branches in a tree must > be of same length. > How do I do this with/without using accumulate or forall? > > Thanks a lot for any help, > > J > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users >

Jeevan, Same idea. You need a helper class that will accumulate your value. []s Edson Jeevan Tambuluri wrote: > Thanks Edson! The rule pattern you suggested works for me. Any such > pattern to simulate "accumulate" in 3.0.x? > > Jeevan > > Edson Tirelli wrote: > >> >> Jeevan, >> >> You are right: the simplest way would be use "forall". >> Unfortunatelly it is only available in trunk. >> To do it in 3.0.x you will need either a helper attribute or a >> helper class. For instance, you may add a "branchLength" attribute >> to the tree and define 2 rules: >> >> rule "define length" >> when >> $t : Tree( branchLength == -1 ) >> Branch( mytree == $t, $bl : branch_length ) >> then >> $t.setBranchLength( $bl.intValue() ); >> modify( $t ); >> end >> >> rule "check length" >> when >> $t : Tree( $bl : branchLength != -1 ) >> exists Branch( mytree == $t, branch_length != $bl ) >> then >> // do something because the branch has a different length >> end >> >> There are several variations but you will need 2 rules to emulate >> this. >> Hopefully the new version will be out soon solving this kind of >> problem. >> >> []s >> Edson >> >> Jeevan Tambuluri wrote: >> >>> Hello all, >>> >>> I am looking for a way to define rules for the following problem: >>> >>> class Tree { >>> ... >>> } >>> >>> class Branch { >>> Tree mytree; >>> int branch_length; >>> ... >>> } >>> >>> Let's say I have a fact called Tree and another fact called Branch. >>> Brach identifies which tree it belongs to. >>> Now, I want to write a rule to say that all branches in a tree must >>> be of same length. >>> How do I do this with/without using accumulate or forall? >>> >>> Thanks a lot for any help, >>> >>> J >>> >>> _______________________________________________ >>> 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 >