title: What does the <primitive: xyz> statement do in a method declaration?
body: <p>Here's the <code>asciiValue</code> method of the <code>Character</code> class:</p>
  <pre><code>asciiValue
     &lt;primitive: 171&gt;
     ^ self primitiveFailed
  </code></pre>
  <p>asciiValue is sent to a character object, for example $A, and returns its ascii code. Can someone explain how does the <code>asciiValue</code> method work? where does that <code>&lt;primitive: 171&gt;</code> comes from and what its purpose?</p>