Intellij Scala not recognizing operators

Question

I'm using the Play Framework with Scala, developing using IntelliJ IDEA Community 13. I've got Play running from a terminal; that's all working. However, IntelliJ isn't recognizing some of the operators used on strings.

Here's my code:

package controllers

import play.api.mvc._
import play.api.libs.json._

object Application extends Controller {

  def index = Action {
    Redirect(routes.Application.tasks)
  }

  def tasks = TODO

  def newTask = TODO

  def deleteTask(id: Long) = TODO

  def sayHello = Action(parse.json) { request =>
    (request.body \ "name").asOpt[String].map { name =>
      Ok(Json.toJson(
        Map("status" -> "OK", "message" -> ("Hello " + name)) // this line
      ))
    }.getOrElse {
      BadRequest("Missing parameter [name]")
    }
  }

}

It compiles and runs fine in Play. However, IntelliJ marks the + and -> operators as invalid, giving me a "Cannot resolve symbol +" when I hover.

I know this is more of an inconvenience than anything else, but it's really bothering me. What do I have to import or configure in order to get IntelliJ to recognize those operators?

Those don't come from Play, they're stock Scala. Most likely you haven't configured the Scala standard library JARs as a dependency for your project. I recommend using SBT and the gen-idea plug-in to generate a complete IDEA project with all its dependencies properly reflecting those in your build.sbt or build.scala file(s). — Randall Schulz

Nikita Volkov Nikita Volkov · Accepted Answer · 2014-01-25T22:02:01

Evidently, JetBrains have taken a "forever in beta" approach with Scala plugin, so be prepared to see bugs frequently. I report them on a daily basis, and I gotta admit, that they do solve the issues I post. Basically what I wanna say is whenever you come across any issue with Scala plugin just post it on their issue tracker.

Intellij Scala not recognizing operators

4 Answers