Proof-of-concept MongoDynamic

MongoDynamic.scala

import com.mongodb._
import org.bson.types.ObjectId

trait MongoDynamic extends Dynamic {
  def applyDynamic(name: String)(args: Any*): MongoDynamic
  def expand[A : Manifest]: Option[A]
}

object EmptyMongoDynamic extends MongoDynamic {
  override def applyDynamic(name: String)(args: Any*): MongoDynamic = EmptyMongoDynamic
  override def expand[A : Manifest]: Option[A] = None
}

case class ValueMongoDynamic[V : Manifest](value: V) extends MongoDynamic {
  override def applyDynamic(name: String)(args: Any*): MongoDynamic = EmptyMongoDynamic
  override def expand[A : Manifest]: Option[A] =
    if (manifest[V] == manifest[A])
      Some(value.asInstanceOf[A])
    else
      None
}

class DynamicDBObject(underlying: DBObject) extends MongoDynamic {
  override def applyDynamic(name: String)(args: Any*): MongoDynamic = {
    underlying.get(name).asInstanceOf[Any] match {
      case null => EmptyMongoDynamic
      case b: Byte => ValueMongoDynamic(b)
      case s: Short => ValueMongoDynamic(s)
      case i: Int => ValueMongoDynamic(i)
      case l: Long => ValueMongoDynamic(l)
      case f: Float => ValueMongoDynamic(f)
      case d: Double => ValueMongoDynamic(d)
      case b: Boolean => ValueMongoDynamic(b)
      case s: String => ValueMongoDynamic(s)
      case oid: ObjectId => ValueMongoDynamic(oid)
      case dbo: DBObject => new DynamicDBObject(dbo)
    }
  }
  override def expand[A : Manifest]: Option[A] =
    if (manifest[A] == manifest[DBObject])
      Some(underlying.asInstanceOf[A])
    else
      None
}

val dbo =
  (BasicDBObjectBuilder.start
    .add("_id", new ObjectId)
    .add("name", "Jorge")
    .push("address")
      .add("street", "36 Cooper Sq")
      .add("city", "New York")
      .add("state", "NY")
    .pop
    .add("age", 26)
    .get)
val d = new DynamicDBObject(dbo)

d.name.expand[String]
// res0: Option[String] = Some(Jorge)

d.name.expand[Int]
// res1: Option[Int] = None

d.address.city.expand[String]
// res2: Option[String] = Some(New York)

d.age.expand[Int]
// res3: Option[Int] = Some(26)

d.age.expand[String]
// res4: Option[String] = None

d._id.expand[ObjectId]
// res5: Option[org.bson.types.ObjectId] = Some(4dd20e58b3150b8279bf339d)

d._id.expand[DBObject]
// res6: Option[com.mongodb.DBObject] = None

d.address.expand[DBObject]
// res7: Option[com.mongodb.DBObject] = Some({ "street" : "1st Ave" , "city" : "New York" , "state" : "NY"})

d.foo.bar.baz.bang.more.stuff.that.dont.exist.expand[String]
// res8: Option[String] = None

Thank you. Me too :)