title: Lazy function arguments?
body: <p>How to make "areYouLazy" function evaluate "string" only once the best possible way?</p>
  
  <pre><code>def areYouLazy(string: =&gt; String) = {
      string
      string
    }
  
  areYouLazy {
    println("Generating a string")
    "string"
  } 
  </code></pre>