Re: [rules-dev] else

Hi Mark, Since you're gathering 2 cents here and there I decided to add also mine even if I am pretty sure that I am still missing the whole picture and anyway at the moment I cannot see all the consequences of what I am going to propose. To tell you the truth I find the label syntax not very intuitive and I was wondering if we could avoid it in some way. In the end what the 90% of the users are asking for is just something like: rule R when A() then do something else do something else end while we are going to give them something that is not exactly the same: rule R when {notA} < A() then do something then.notA do something else end In particular I was thinking if we could keep the when ... then ... else syntax that should be familiar to the biggest part of the users and at the same time obtain a flexibility similar to the one provided by the labels syntax. Probably we could do it with a kind of nested rules so, for instance, the rule: rule R1 when {af} < A() > {at} B() then DO then.af <http://then.af> DO.af then.at <http://then.at> DO.at end could be rewritten as it follows: rule R1 when B() then DO rule R1A when A() then DO.at else DO.af end end Of course the nested rule couldn't be used by the Drools engine as it is, but we could implement a kind of "linearization" process at compile time that translates it more or less as: rule R1_1 when A() B() then DO DO.at end rule R1_2 when not A() B() then DO DO.af end In the same way the "or" example: rule R1 when ( A() > {a1} or B() > {b1} or C() > {c1} ) D() then DO then.a1 DO.a1 then.b1 DO.b1 then.c1 DO.c1 end could be written as: rule R1 when D() then DO rule R1A when A() then DO.a1 end rule R1B when B() then DO.b1 end rule R1C when C() then DO.c1 end end and then linearized at compile time in a similar way as I wrote before. Once again I still haven't evaluated all the implications of my suggestion neither I know if we can cover with it all the cases proposed by Mark. I am pretty sure I am missing something important to be honest, but since we are in a "brainstorming phase" I thought it could worth to consider it at least. My 2 cents, Mario _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev