title: How to convert UTF8 byte arrays to string in lua
body: <p>I have a table like this</p>
  
  <pre><code>table = {57,55,0,15,-25,139,130,-23,173,148,-24,136,158}
  </code></pre>
  
  <p>it is utf8 encoded byte array by php unpack function </p>
  
  <pre><code>unpack('C*',$str);
  </code></pre>
  
  <p>how can I convert it to utf-8 string I can read in lua?</p>