Scala macro for accessing Typesafe Config objects

TypesafeConfigMacros.scala

import com.typesafe.config.Config

import scala.language.experimental.macros
import scala.reflect.macros.whitebox
import scala.reflect.runtime.universe._


object TypesafeConfigMacros {

  def asImpl[T: c.WeakTypeTag](c: whitebox.Context)(key: c.Expr[String])(tag: c.Expr[WeakTypeTag[T]]): c.Expr[Option[T]] = {
    import c.universe._

    def genPrimitiveGetter(conf: c.Expr[Config], key: c.Expr[String], tpe: String): c.Expr[Option[T]] = {
      val methodName = TermName(s"get$tpe")
      c.Expr[Option[T]](q"Some($conf.$methodName($key))")
    }

    def genListGetter(conf: c.Expr[Config], key: c.Expr[String], tpe: String): c.Expr[Option[T]] = {
      val methodName = TermName(s"get${tpe}List")
      c.Expr[Option[T]]( q"""Some(scala.collection.JavaConversions.asScalaBuffer($conf.$methodName($key)).toList)""")
    }

    val tpe = c.weakTypeOf[T]
    val conf = c.Expr[Config](q"conf")
    val expr = tpe match {
      case x if tpe <:< typeOf[String] => genPrimitiveGetter(conf, key, tpe.toString)
      case x if tpe <:< typeOf[Long] => genPrimitiveGetter(conf, key, tpe.toString)
      case x if tpe <:< typeOf[Int] => genPrimitiveGetter(conf, key, tpe.toString)
      case x if tpe <:< typeOf[Double] => genPrimitiveGetter(conf, key, tpe.toString)
      case x if tpe <:< typeOf[Boolean] => genPrimitiveGetter(conf, key, tpe.toString)
      case x if tpe <:< typeOf[Config] => genPrimitiveGetter(conf, key, "Config")
      case x if tpe <:< typeOf[List[String]] => genListGetter(conf, key, "String")
      case x if tpe <:< typeOf[List[Long]] => genListGetter(conf, key, "Long")
      case x if tpe <:< typeOf[List[Int]] => genListGetter(conf, key, "Int")
      case x if tpe <:< typeOf[List[Double]] => genListGetter(conf, key, "Double")
      case x if tpe <:< typeOf[List[Boolean]] => genListGetter(conf, key, "Boolean")
      case x if tpe <:< typeOf[List[Config]] => genListGetter(conf, key, "Config")
      case _ => c.abort(c.enclosingPosition, s"Unsupported data type: ${tpe.toString}")
    }

    //println(showCode(q""" if($conf.hasPath($key)) { $expr } else { Option.empty[$tpe] } """))
    c.Expr[Option[T]](q""" if($conf.hasPath($key)) { $expr } else { Option.empty[$tpe] } """)
  }
}