[rules-users] [planner] Drools planner & Scala => Solution.getScore():Score<?>

[Geoffrey De Smet]

Apparently, other people are combining Scala with Drools Planner and 
running into this problem too:
   
http://stackoverflow.com/questions/5279149/implementing-methods-having-raw-types-in-scala
So I created an issue and fixed it:
   https://issues.jboss.org/browse/JBRULES-2924

Op 06-02-10 14:28, Adam Warski schreef:
> Hello,
>
>> Michael Neale (the drools guvnor guy) is also using Scala and Drools
>> Planner together. His code is at github.
> I was looking for his account but a search for "Neale" only finds some comments in BMW's repos. You know what his username is?
>
>> If the issue still makes sense, feel free to open an issue for the
>>    org.drools.planner.core.solution.Solution#getScore():Score<?>
>> discussion (and copy this part of the discussion).
>> Why should it be Score<?>  and not
>> 2) Score<S extends Score>
>> 3) or Score<<S extends Score<S extends Score>  >>  ?
> Well in case 2) Scala would still complain about a missing type parameter for the inner Score. Same for 3, it could go on forever. So for recursive type parameters you need to stop at some point and put in a wildcard (? in java or _ in scala). Score<?>  and Score have the same meaning in Java (they both mean any Score), the only difference is that one works, the other not in Scala ;). And for the use in the Solution interface I think it's write - the get/set method store any score, you don't know which one.
>
>> 4) Or maybe it should be, just like EnumSet?
>> class Solution<S extends Score>  {
>>     public S getScore()
>> }
> This would of course work also, but it's a much bigger refactoring. And it could have some viral consequences. Score<?>  instead of Score is just a drop-in replacement :).
>

-- 
With kind regards,
Geoffrey De Smet