Issue
- Make
RelationDef abstract and use subtypes to define specific Relation implementations
Problem Description
- Currently a
RelationDef can be used to define an arbitrary Relation implementation (SingleRowRelation, RowRelation, ColumnRelation, etc.)
- The semantic of a
RelationDef therefore is merely a schema definition
- This leads to a mix of concerns when defining
Dactors because only there it is defined what kind of Relation is actually instantiated from the RelationDef
- Proposed interface allows for clear definition syntax even when using various
Relation types in a Dactor:
// Companion object
object Info extends SingleRowRelationDef("info") {
// [...]
}
object Cast extends RowRelationDef("cast") {
// [...]
}
// Dactor
class Film(id: Int) extends Dactor(id) {
override protected val relations: Map[RelationDef, MutableRelation] =
createRelations(Set(Film.Info, Film.Cast)) // a single relation instantiation function!
override def receive: Receive = Actor.emptyBehavior
}
- This will also make it easier to develop a DSL for data modelling
