How to convert MongoDBList to BasicDBList?

Question

I use Casbah 2.5.0. There is example in tutorial:

scala> val builder = MongoDBList.newBuilder
scala> builder += "foo"
scala> builder += "bar"
scala> builder += "x"
scala> builder += "y"
builder.type = com.mongodb.casbah.commons.MongoDBListBuilder@...

scala> val newLst = builder.result
newLst: com.mongodb.BasicDBList = [ "foo" , "bar" , "x" , "y"]

So newLst here is BasicDBList.

But when I try it myself, it works different.

scala> val builder = MongoDBList.newBuilder
scala> builder += "foo"
scala> builder += "bar"
scala> val newLst = builder.result
newLst: com.mongodb.casbah.commons.MongoDBList = [ "foo" , "bar"]

newLst here is of type MongoDBList.

Why is so? How can I convert MongoDBList to BasicDBList?

Answer 1

There is an implicit conversion from com.mongodb.casbah.commons.MongoDBList to com.mongodb.BasicDBList in casbah (check com.mongodb.casbah.commons.Implicits):

implicit def unwrapDBList(in: MongoDBList): BasicDBList = in.underlying

Just pass MongoDBList to position where BasicDBList is expected:

scala>  val l: BasicDBList = newLst
l: com.mongodb.casbah.Imports.BasicDBList = [ "foo" , "bar"]

If you want to create MongoDBList from List:

scala>  val list = List("foo", "bar")
list: List[java.lang.String] = List(foo, bar)

scala>  val dbList = MongoDBList(list:_*)
dbList: com.mongodb.casbah.commons.MongoDBList = [ "foo" , "bar"]