AST transform on AsyncResult methods

WhatWeCouldDo.groovy

// Let's imagin you have such a service
class TodoMongoService {
  void fetchById(String todoId, Handler<AsyncResult<Todo>> handler) {
    mongo.find(id) { res ->
      if(res.succeeded) {
        handler.handle(Future.suceededFuture(res.result))
      } else {
        handler.handle(Future.failedFuture(res.cause))
      }
    }
  }
}

// Through an AST transformation we could extend the class this way : 
class TodoMongoService {
  
  // same method as above here...
  
  // plus a generated method ready to be used in a vertx-web context
  Handler<RoutingContext> fetchById(String todoId) {
    return { ctx ->
      findById(todoId) { res ->
        if (res.failed) {
          ctx.fail(res.cause)
        } else {
          ctx.yield(res.result)
        }
    }
  }
}

// Because that's a common pattern I found myself a lot of times.
// This way we could write something like that :
router.get('/todos/:id') >> fetchById(id)

// Which "looks like" currying even though that's not really currying