title: Can't use a negative number in named parameters in Scala
body: <p>I'm using Scala 2.11.2.</p>
  
  <p>If I have this Fraction class:</p>
  
  <pre><code>case class Fraction(numerator: Int, denominator: Int) {}
  </code></pre>
  
  <p>Then this gives an error:</p>
  
  <pre><code>val f = new Fraction(numerator=-1, denominator=2)
  </code></pre>
  
  <p>But this is not:</p>
  
  <pre><code>val f = new Fraction(-1, denominator=2)
  </code></pre>
  
  <p>The error message is:</p>
  
  <pre><code>Multiple markers at this line
  - not found: value 
   numerator
  - not found: value 
   numerator
  </code></pre>
  
  <p>I tried to use negative numbers in other snippets with the same result, but the documentation doesn't mentions that this is not possible.</p>
  
  <p>Am I doing something wrong?</p>
  
  <p>Thanks</p>