Document.scala

package com.mongodb.casbah
package commons

object Syntax extends Syntax

trait Syntax {
  implicit def name(name: String) = Name(name)
}

case class Name(name: String) {
  def :=[A](a: A)(implicit value: Value[A]) = name -> value.value(a)
}

@annotation.implicitNotFound("${A} is not a valid MongoDb value")
trait Value[-A] {
  def value(a:A):Any
}

object Value extends Values {
  def apply[A](f:A => Any):Value[A] = new Value[A]{
    def value(a: A) = f(a)
  }
}

trait Values extends LowPriority {
  implicit val string = Value[String](identity)
  implicit val int = Value[Int](identity)
  implicit val double = Value[Double](identity)
  implicit def option[A](implicit value:Value[A]) = Value[Option[A]](_.map(value.value))  
  implicit val none = Value[None.type](identity)
  implicit val nil = Value[Seq[Nothing]](identity) 
}
  
trait LowPriority {
  implicit def seq[A](implicit value:Value[A]) = Value[Seq[A]](_.map(value.value))  
}  

DocumentTest.scala

import com.mongodb.casbah.commons._

class DocumentTest {

  import Syntax._

  MongoDbObject(
    "string"       := "string", 
    "int"          := 5, 
    "double"       := 5.5,
    "option"       := Option[String]("x"),
    "literal some" := Some("y"),
    "literal none" := None,
    "seq"          := Seq("a", "b"),
    "nil"          := Nil
  )
  
}