gistfile1.txt

    def jsonReader(className: TypeName, fields: List[ValDef]) = {
      fields.length match {
        case 0 => c.abort(c.enclosingPosition, "Cannot create json formatter for case class with no fields")
        case _ =>
          // use the serializer for the field
          val readers = getReaders(fields)
          q"""
            implicit object reader extends BSONDocumentReader[$className] {
              import reactivemongo.bson._
              def read(bson: BSONDocument): $className = {
                ${className.toTermName}(..$readers)
              }
            }
          """
      }
    }
    def jsonWriter(className: TypeName, fields: List[ValDef]) = {
      fields.length match {
        case 0 => c.abort(c.enclosingPosition, "Cannot create json formatter for case class with no fields")
        case _ =>
          // use the serializer for the field
          val writers = getWriters(fields)
          q"""
            implicit object writer extends BSONDocumentWriter[$className] {
              def write(obj: $className): BSONDocument = {
                BSONDocument(..$writers)
              }
            }
          """
      }

    def modifiedDeclaration(classDecl: ClassDef, compDeclOpt: Option[ModuleDef] = None) = {
      val (className, fields) = extractClassNameAndFields(classDecl)
      val readerFormat = jsonReader(className, fields)
      val writerFormat = jsonWriter(className, fields)
      val readerCompDecl = modifiedCompanion(compDeclOpt, readerFormat, className)
      val writerCompDecl = modifiedCompanion(compDeclOpt, writerFormat, className)

      // Return both the class and companion object declarations
      c.Expr(q"""
        $classDecl
        $readerCompDecl
        $writerCompDecl
      """)
    }

    def modifiedCompanion(compDeclOpt: Option[ModuleDef], format: ModuleDef, className: TypeName) = {
      compDeclOpt map { compDecl =>
        // Add the formatter to the existing companion object
        val q"object $obj extends ..$bases { ..$body }" = compDecl
        q"""
          object $obj extends ..$bases {
            ..$body
            $format
          }
        """
      } getOrElse {
        // Create a companion object with the formatter
        q"object ${className.toTermName} { $format }"
      }
    }