How to turn an Anorm RowParser[A] into RowParser[Option[A]]

Question

I use Scala Anorm for a project and I like to write parsers for case classes. I then reuse these parsers for other queries - typically when adding a JOIN.

Now sometimes, I expect an optional value (i.e. LEFT JOIN instead o of JOIN). It would be very handy to be able to reuse the same parser, any idea on how to achieve this?

As an example, say I have the following case class:

case class Specialty(
  id: Long,
  name: String
)

with the following parser:

def parser(table: String): RowParser[Specialty] = {
    get[Long]("id") ~ get[String](table + ".name") map {
      case id ~ name => Specialty(id, name)
    }
  }

How can I turn parser:RowParser[Specialty] into parser:RowParser[OptionSpecialty]]?

This would enable me to use it in a query where the table specialty is added through a LEFT JOIN.

As an extra piece of information, now I rewrite the parser like this:

def parserOptional(table: String):RowParser[Option[Specialty]] = {
    get[Option[Long]]("id") ~ get[Option[String]](table + ".name") map {
      case oid ~ oname => oid.flatMap{id =>
        oname.map{name =>
          Specialty(id, name)
        }
      }
    }
  }

Answer 1

based on this, I think I found the answer

use (parser ?) or

def parserOptional(table: String):RowParser[Option[Specialty]] = parser(table) ?