绑定变量似乎被错误地识别为方法

Question

drl:

rule "adjectFreePeriods"
    when
        $studentGroupAndEduClass : StudentGroupAndEduClass($eduClasses : eduClasses)
        not LectureOfEduClass(eduClass memberOf $eduClasses,
            $day : day, $timeslotIndex : timeslotIndex, period != null
        )
        not LectureOfEduClass(eduClass memberOf $eduClasses,
            $day == day, timeslotIndex == ($timeslotIndex + 1)
        )
    then
        scoreHolder.addSoftConstraintMatch(kcontext,- $studentGroupAndEduClass.getStudents().size());
end

java:

public class LectureOfEduClass{
    // ...
    //omitted others
    public Day getDay(){
        if(period == null){
            return null;
        }
        return period.getDay();
    }
    public int getTimeslotIndex() {
        if (period == null) {
            return Integer.MIN_VALUE;
        }
        return period.getTimeslot().getTimeslotIndex();
    }
}

这是确切的错误消息。

Unable to Analyse Expression $day == day:
[Error: unable to resolve method using strict-mode: domain.LectureOfEduClass.$day()]
[Near : {... $day == day ....}]
             ^
Unable to Analyse Expression timeslotIndex == ($timeslotIndex + 1):
[Error: unable to resolve method using strict-mode: domain.LectureOfEduClass.$timeslotIndex()]
[Near : {... timeslotIndex == ($timeslotIndex + 1) ....}]
                               ^

根据显示的错误消息，引擎似乎错误地将这两个绑定变量作为 POJO 的方法。这些代码片段有什么问题？我该如何解决？

Answer 1

问题是您在 not 模式中绑定 $day。由于显而易见的原因，not（或 exists）模式中的所有变量都是该模式的局部变量。我认为你正在尝试做的是这样的：

rule "adjectFreePeriods"
when
  $studentGroupAndEduClass : StudentGroupAndEduClass($eduClasses : eduClasses)
  not (
    LectureOfEduClass(
      eduClass memberOf $eduClasses,
      $day : day, 
      $timeslotIndex : timeslotIndex, period != null
    ) and
    LectureOfEduClass(
      eduClass memberOf $eduClasses,
      $day == day, 
      timeslotIndex == ($timeslotIndex + 1)
    )
  )
then
  scoreHolder.addSoftConstraintMatch(kcontext,- $studentGroupAndEduClass.getStudents().size());
end

希望对您有所帮助，

绑定变量似乎被错误地识别为方法

Binding variables seemed to be recognized as methods incorrectly

drools

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