How to compose function to applicatives with scalaz

Question

While learning Scalaz 6, I'm trying to write type-safe readers returning validations. Here are my new types:

type ValidReader[S,X] = (S) => Validation[NonEmptyList[String],X]
type MapReader[X] = ValidReader[Map[String,String],X]

and I have two functions creating map-readers for ints and strings (*):

def readInt( k: String ): MapReader[Int] = ...
def readString( k: String ): MapReader[String] = ...

Given the following map:

val data = Map( "name" -> "Paul", "age" -> "8" )

I can write two readers to retrieve the name and age:

val name = readString( "name" )
val age = readInt( "age" )

println( name(data) ) //=> Success("Paul")
println( age(data) )  //=> Success(8)

Everything works fine, but now I want to compose both readers to build a Boy instance:

case class Boy( name: String, age: Int )

My best take is:

  val boy = ( name |@| age ) {
    (n,a) => ( n |@| a ) { Boy(_,_) }
  }
  println( boy(data) ) //=> Success(Boy(Paul,8))

It works as expected, but the expression is awkward with two levels of applicative builders. Is there a way, to get the following syntax to work ?

  val boy = ( name |@| age ) { Boy(_,_) }

(*) Full and runnable implementation in: https://gist.github.com/1891147

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Update: Here is the compiler error message that I get when trying the line above or Daniel suggestion:

[error] ***/MapReader.scala:114: type mismatch;
[error]  found   : scalaz.Validation[scalaz.NonEmptyList[String],String]
[error]  required: String
[error]   val boy = ( name |@| age ) { Boy(_,_) }
[error]                                    ^