title: how could i return multiple values from a function in haskell?
body: <p>Is it possible for a function to return multiple values – e.g., a string and a Boolean?</p>
  <p>If yes, then I have a function called <code>concat</code> which returns a <code>Bool</code> and a <code>String</code>, but I don't know how to call that function so I can store the result.</p>
  <p>Example attempt:</p>
  <pre><code>concat::(String-&gt;Int)-&gt;(IO Bool-&gt;IO String)
  concat line i=do
         return True line
  </code></pre>
  <p>Can you help me to write the function signature and how to call those functions?</p>