[rules-users] Drools planner & Scala
Hello,
I'm using Planner in a Scala program and it almost works without problems; the only
one is in implementing the Solution interface, as it uses raw (erased) version of Score,
which is normally generic (Score<S extends Score>). Scala generally doesn't like
raw types and in most cases it's impossible to extend/implement interfaces which use
them. A work-around is to introduce an "adapter" in Java, which you can later
extend in Scala:
public abstract class ScalaSolution implements Solution {
public Score getScore() { return getScoreScala(); }
public abstract Score<?> getScoreScala();
public void setScore(Score score) { setScoreScala(score); }
public abstract void setScoreScala(Score<?> score);
}
and then in Scala:
class Schedule(...) extends ScalaSolution {
var score: Score[_] = _
def setScoreScala(score: Score[_]) = { this.score = score }
def getScoreScala = score
...
}
So the fix is to replace the raw Score type with Score<?>. Maybe it would be
possible to apply that in the code? I tried it locally and it compiles without problems.
And a side question: do you have any plans on implementing multithreading in planner? So
that several moves could be explored concurrently? I saw there's an open Jira issue
for some time, but it didn't have any timeframe information.
--
Adam Warski
http://www.warski.org
http://www.softwaremill.eu