Dotty inheritance of path dependent types

Prefix.scala

package org.w3.banana

import scala.util._


trait Prefix[T <: RDFObj](using val rdf: T) {
  def prefixName: String
  def prefixIri: String
  def apply(value: String): rdf.URI
  def unapply(iri: rdf.URI): Option[String]
}

object Prefix {
  def apply[T <: RDFObj](using rdf: T)(
    prefixName: String,
    prefixIri: String
  )(using ops: RDFOps[rdf.type]): Prefix[rdf.type] =
    new PrefixBuilder[T]()(prefixName, prefixIri).asInstanceOf[Prefix[rdf.type]]
}

class PrefixBuilder[T <: RDFObj](using val rdf2: T)(
  val prefixName: String,
  val prefixIri: String
)(using val ops: RDFOps[rdf2.type]) extends Prefix[rdf2.type](using rdf2) { 
  import ops._

  override def toString: String = "Prefix(" + prefixName + ")"

  def apply(value: String): rdf.URI = makeUri(prefixIri + value)

  def unapply(iri: rdf.URI): Option[String] = {
    val uriString = fromUri(iri)
    if (uriString.startsWith(prefixIri))
      Some(uriString.substring(prefixIri.length))
    else
      None
  }

  def getLocalName(iri: rdf.URI): Try[String] =
    unapply(iri) match {
      case None => Failure(Exception(this.toString + " couldn't extract localname for " + iri.toString))
      case Some(localname) => Success(localname)
    }

}

object RDFSPrefix {
  def apply[T <: RDFObj](using rdf: T)(using ops: RDFOps[rdf.type]) = new RDFSPrefix()
}

class RDFSPrefix[T <: RDFObj](using val rdf3: T)(using override val ops: RDFOps[rdf3.type])
  extends PrefixBuilder[rdf3.type](using rdf3)("rdfs", "http://www.w3.org/2000/01/rdf-schema#") { 
  val Class = apply("Class")
  val Container = apply("Container")
  val ContainerMembershipProperty = apply("ContainerMembershipProperty")
  val Datatype = apply("Datatype")
  val Literal = apply("Literal")
  val Resource = apply("Resource")
  val comment = apply("comment")
  val domain = apply("domain")
  val isDefinedBy = apply("isDefinedBy")
  val label = apply("label")
  val member = apply("member")
  val range = apply("range")
  val seeAlso = apply("seeAlso")
  val subClassOf = apply("subClassOf")
  val subPropertyOf = apply("subPropertyOf")
}