当2个对象共享一个属性时触发的Drools规则

Question

rule "704.5j. If two or more planeswalkers that share a planeswalker type are on the battlefield, all are put into their owners' graveyards. This is called the 'planeswalker uniqueness rule'."
    when
        $c1 : Card (CurrentZone == ZoneType.Battlefield , Types.contains("Planeswalker") , $subtype : Types.get(1) , $c1ID : ID );
        $c2 : Card (CurrentZone == ZoneType.Battlefield , Types.contains("Planeswalker") , Types.contains($subtype) , ID != $c1ID);
    then
        System.out.println("PW Uniqueness: " + $c1.getName() + " | " + $c2.getName());
        $c1.setCurrentZone(ZoneType.Graveyard);
        $c2.setCurrentZone(ZoneType.Graveyard);
end

我必须在java方面这样做吗？

编辑：同时，非常欢迎针对Drools的教程/指南建议。

Answer 1

如果你还没有做到这一点，也许可以将一个部分移到Then部分的If中，以避免在when中声明内容，然后在同一个部分中召回它，

rule "704.5j. If two or more planeswalkers that share a planeswalker type are on the battlefield, all are put into their owners' graveyards. This is called the 'planeswalker uniqueness rule'."
when
    $c1 : Card (CurrentZone == ZoneType.Battlefield , Types.contains("Planeswalker") ,($subtype : Types.get(1)));
    $c2 : Card (CurrentZone == ZoneType.Battlefield , Types.contains("Planeswalker") ,($subtype2 : Types.get(1)) );
then
    if (($subtype == $subtype2) && ($c1.getID() == $c2.getID()))
    {
       System.out.println("PW Uniqueness: " + $c1.getName() + " | " + $c2.getName());
       $c1.setCurrentZone(ZoneType.Graveyard);
       $c2.setCurrentZone(ZoneType.Graveyard);
    }
end

这有点冗长。但是我通常避免在When中声明和检查相同的变量，我声明我需要的一切（大多数时候使用数组和evals)，然后在then中检查IF状态。

同样，正如@Marko所说，将第一个属性取下来，检查它的工作情况，然后一次只添加一个检查。有时我会用大量愚蠢的IFs等构建大规则，一旦它起作用了。我开始缩小尺寸。减少一件工作的东西比修复一件小坏的东西容易：）