compose handleException taking parameters [1.1.1]

[Ryan O'Rourke]

Hi,

I have an exception handler where I want to reference values that have already been extracted in the route. I can get this to work by nesting the handleExceptions directive in the routing tree, but I'd like to compose it with the directive that does the extraction. I cannot figure out a way to do that. 

Here's the way that works, with the handleExceptions directive nested.

  // modified example at http://spray.io/documentation/1.1.2/spray-routing/execution-directives/handleExceptions/

  val dividePath = path("divide" / IntNumber / IntNumber)

  val handler = (a: Int, b: Int) => ExceptionHandler {

    case _: ArithmeticException => complete(StatusCodes.BadRequest, s"You can't divide $a by $b")

  }

  val route =

    dividePath { (a, b) =>

      handleExceptions(handler(a, b)) {

        complete(s"The result is ${a / b}")

      }

    }

  describe("adhoc") {

    it("works") {

      Get("/divide/10/5") ~> route ~> check {  responseAs[String] shouldEqual "The result is 2"  }

    }

    it("fails") {

      Get("/divide/10/0") ~> route ~> check {

        status === StatusCodes.BadRequest

        responseAs[String] shouldEqual "You can't divide 10 by 0"

      }

    }

  }

So I'd like to combine "dividePath" and "handler" into a single directive, something like:

  // doesn't compile: found   : spray.routing.Directive0, required: spray.routing.RequestContext => Unit (i.e., Route)

  val both = dividePath { (a,b) => handleExceptions(handler(a,b)) }

If I try to compose using "&" the types line up of course, but as far as I can tell there's no way to get access to the (a,b) extracted by "dividePath".