title: Can a typescript parameter be annotated as const?
body: <p>If I do not want the value of a parameter change within a function scope, is there any way to annotate that with Typescript?</p>
  
  <p>I've tried:</p>
  
  <pre><code>function walk(const fileName: string): string[] {
  // -----------^
  }
  </code></pre>
  
  <p>But it does not work.</p>