title: Get expression parameter name
body: <p>I need to get the name of a expression parameter. What i want to do is similar to what FluentNhibernate does with column mapping:</p>
  
  <blockquote>
    <p>Map(x => x.Name)</p>
  </blockquote>
  
  <p>From this, i need "Name".</p>
  
  <p>How do I do this?</p>
  
  <p>I can get <code>x</code> by doing this:</p>
  
  <pre><code>Expression&lt;Func&lt;User, object&gt;&gt; exp = x =&gt; x.Id;
  exp.Parameters[0].Name;
  </code></pre>
  
  <p>But im not able to get "Name". Note that I dont have any instance of T i can invoke on.
  Thanks</p>