title: Scala Slick Comprehension issues
body: <p>I have the following in a library:</p>
  
  <p>Case Class:</p>
  
  <pre><code>case class Foo(
    id: Option[Long],
    bar: Long
  ...
  )
  </code></pre>
  
  <p>Table: </p>
  
  <pre><code>object Foos extends Mapper[Foo]("foo"){ //I'm using slick-inegration so the id is free
    def bar = column[Long]("bar")
    def cols = bar ~ ...
    def * = id.? ~: cols &lt;&gt; (Foo, Foo.unapply _)
    def returningId = cols returning id
    def insert(f: Foo)(implicit s: Session) = returningId.insert(Generic[Foo].to(f).tail.tupled)
  
  ...
  }
  </code></pre>
  
  <p>The data access layer is set up in the binary that utilizes these models.  If I try a comprehension such as "for(f&lt;-Foos) yield f", inside of the Foos definition, we're happy.  If I try it anywhere in the codebase which uses this library, I get:</p>
  
  <pre><code>value map is not a member of object DB.this.Foos
  </code></pre>
  
  <p>My guess is it's not getting lifted into a Query, but I'm not entirely sure.  Any clarity would be appreciated.</p>