title: How to determine the datatype of a variable
body: <p>It is an easy to answer question (I guess), but I looked for a while not finding anything so I will direct my question to you.</p>
  
  <p>There is the <code>typep</code> to determine whether a given variable is of some specific data-type e.g. integer,hashtable etc. , but is there a function which returns the data-type?</p>
  
  <p>e.g.</p>
  
  <pre><code>(defvar *x* 1)
  *x*
  
  (typep *x* 'integer)
  T
  
  (the-type-function *x*)
  INTEGER
  </code></pre>