CODEWITHSUNDEEP
scalaintellij-idearabbitmqshapeless
Dario Lötscher
Dario Lötscher

Reputation: 99

Scala Intellij - Op-Rabbit Syntax highlighting issue

I'm trying to use op-rabbit https://github.com/SpinGo/op-rabbit to connect my Scala App to RabbitMq. The example code https://github.com/SpinGo/op-rabbit/blob/master/demo/src/main/scala/demo/Main.scala works perfectly fine.

I want to work on it with the Intellij-idea. The IDE makes problems on the consume code:

channel(qos=3) {
  consume(demoQueue) {
    body(as[Data]) { data =>
      println(s"received ${data}")
      ack
    }
  }
}

I get an error on data => ... it says its a type mismatch

Type mismatch, expected: ::[Data, HNil] => op_rabbit.Handler, actual: Data => op_rabbit.Handler

I would be absolutly fine with annotating the data variable manually if this solves the problem i tried to annotated data as HList from shapeless.

channel(qos=3) {
  consume(demoQueue) {
    body(as[Data]) { data: HList =>
      println(s"received ${data}")
      ack
    }
  }
}

The IDE was happy with it... unlucky the compiler not really :D :( . Like this the code doesnt compile anymore.

Any idea?

Intellij and the Scala Plugin are updated to the newest version.

Upvotes: 3

Views: 150

Answers (2)

Dmytro Mitin
Dmytro Mitin

Reputation: 51703

Well, it's better if IDE complains and not compiler does.

Type of data is Data and not HList or Data :: HNil

channel(qos=3) {
  consume(demoQueue) {
    body(as[Data]) { (data: Data) =>
      println(s"received ${data}")
      ack
    }
  }
}

You should get used that IDE highlights code in Scala sometimes incorrectly. Path-dependent types, implicits, macros etc. are sometimes too complicated for IDE to handle.

The following code is highlighted correctly in 2017.3 EAP (Ultimate Edition) Build #IU-173.3302.5

val directive = body(as[Data])

channel(qos = 3)(
  consume(demoQueue)(
    directive(data => {
      println(s"received ${data}")
      ack
    })
  )
)

Upvotes: 3

Dario Lötscher
Dario Lötscher

Reputation: 99

As a short term solution i took this way:

val handle = (data: Data) => {
  println(s"received ${data}")
  ack
}

val demoQueue = Queue("demo", durable = false, autoDelete = true)
val subscription = Subscription.run(rabbitControl) {
  channel(qos=3) {
    consume(demoQueue) /*_*/ {
      body(as[Data]) {handle}
    }
  }
}

I disabled the type check on the problematic block. Nevertheless i want to have type checking in my handling code. I moved that part out to the handle function. This way the IDE checks the handle function. With /* _ */ you can disable type checking on a specific part of the code.

Still hope for better solutions.

Upvotes: 1

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