title: In Lua how do you import modules?
body: <p>Do you use</p>
  
  <pre><code>require "name"
  </code></pre>
  
  <p>or</p>
  
  <pre><code>local name = require "name"
  </code></pre>
  
  <p>Also, do you explicitly declare system modules as local variables? E.g.</p>
  
  <pre><code>local io = require "io"
  </code></pre>
  
  <p>Please explain your choice.</p>
  
  <p>Programming in Lua 2ed says "if she prefers to use a shorter name for a module, she can set a local name for it" and nothing about <code>local m = require "mod"</code> being faster than <code>require "mod"</code>. If there's no difference I'd rather use the cleaner <code>require "mod"</code> declaration and wouldn't bother writing declarations for pre-loaded system modules.</p>