closure_reflection.scala

// now:
def query[T](predicate: T => Boolean): List[T] = macro queryMacro

def queryImpl[T: c.TypeTag](c: Context)(predicate: c.Expr[T => Boolean]): c.Expr[List[T]]

// with something like closure reflection:

//    the library:
class ReflectiveClosure[A,B] extends Function1[A,B] {
  def ast: Expression  
}

implicit def reflectClosure[A,B](f: Function1[A,B]): ReflectiveClosure[A,B] = macro reflectiveClosureImpl
def reflectiveClosureImpl[A: c.TypeTag, B: c.TypeTag](c:Context)(f:c.Expr[Function1[A,B]]):c.Expr[ReflectiveClosure[A,B]] = ???

//    the consumer:
def query[T](predicate: ReflectiveClosure[T,Boolean]): List[T] = {
  val ast = predicate.ast
  ???
}