title: Scala compiler says: value & is not a member of java.lang.object
body: <p>I am very new to Scala, I try some tutorials but I didn't get the point in this problem here:</p>
  
  <pre><code>val reverse = new mutable.HashMap[String, String]() with mutable.SynchronizedMap[String, String]  
  
  def search(query: String) = Future.value {
    val tokens = query.split(" ")
    val hits = tokens map { token =&gt; reverse.getOrElse(token, Set()) }
    if (hits.isEmpty)
      Nil
    else
      hits reduceLeft {_ &amp; _} toList // value &amp; is not a member of java.lang.Object
  }
  </code></pre>
  
  <p>The compiler says value &amp; is not a member of java.lang.Object. Can somebody explain me why I am getting a compiler error ? I have this from this tutorial here: <a href="https://twitter.github.io/scala_school/searchbird.html" rel="nofollow">https://twitter.github.io/scala_school/searchbird.html</a></p>