Scala example source code file (t2082.scala)

This example Scala source code file (t2082.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

ctype, ctype, idpk, keyedmapper, keyedmapper, keyedmetamapper, mappedforeignkey, mapper, metatestsubject, t, testrun, testrun, testsubject, testsubject

The Scala t2082.scala source code

trait Mapper[T <: Mapper[T]]

trait KeyedMapper[KeyType, T <: KeyedMapper[KeyType, T]] extends Mapper[T] 


trait KeyedMetaMapper[KeyType, T <: KeyedMapper[KeyType, T]] 

trait MappedForeignKey[KeyType, Owner <: Mapper[Owner], Other <: KeyedMapper[KeyType, Other]]

trait IdPK

class TestSubject extends KeyedMapper[Long, TestSubject] with IdPK

class TestRun extends KeyedMapper[Long, TestRun] with IdPK {
	object testSubject extends MappedForeignKey[Long, TestRun, TestSubject]
}

object TestRun extends TestRun with KeyedMetaMapper[Long, TestRun]

class MetaTestSubject extends TestSubject with KeyedMetaMapper[Long, TestSubject]
object TestSubject extends MetaTestSubject 

object Main {
  
  def oneToOneJoin[PType <: KeyedMapper[Long, PType] with IdPK,
                   CType <: KeyedMapper[Long, CType] with IdPK,
                   CMetaType <: CType with KeyedMetaMapper[Long, CType], 
                   FKType <: MappedForeignKey[Long, PType, CType]]
  (parents: List[PType], metaMapper: CMetaType, keyGetter: (PType) => FKType ): 
  Map[Long, CType] = Map.empty
  
  def callIt {
    oneToOneJoin[TestRun, TestSubject, MetaTestSubject, 
                 MappedForeignKey[Long, TestRun, TestSubject]](
    List(), TestSubject, (tr: TestRun) => tr.testSubject)
  }

}