title: IntelliJ Scala worksheet - package names don't correspond to directories
body: <p>I'm doing Martin Odersky's course on coursera.com and he has a class defined within a Scala Worksheet like this:</p>
  
  <pre><code>object intsets {
    println("Welcome to Scala WS")
  }
  
  abstract class IntSet {
    def incl(x: Int): IntSet
    def contains(x: Int): Boolean
  }
  </code></pre>
  
  <p>And when I do it in my worksheet I get a warning: "Package names doesn't correspond to directories structure, this may cause problems with resolve to classes from this file".
  Project is freshly created using New Project -> Scala -> SBT. IntelliJ 2017.</p>
  
  <p>Here is a screenshot: <a href="https://i.stack.imgur.com/coyJq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/coyJq.png" alt="enter image description here"></a></p>