title: Can a vertical bar be used as part of an identifier in Racket?
body: <p>I would like to define a variable in Racket for a quantum state, which is written by convention as:</p>
  
  <p><img src="https://chart.googleapis.com/chart?cht=tx&amp;chl=%7C0%5Cra" alt="foo+bar"></p>
  
  <p>The <a href="http://docs.racket-lang.org/reference/reader.html?q=reader" rel="nofollow">Reader reference</a> tells me this is not possible, because:</p>
  
  <blockquote>
    <p><code>|</code> starts a subsequence of characters to be included verbatim in the delimited sequence</p>
  </blockquote>
  
  <p>However, I am surprised to find that page <a href="http://rosettacode.org/wiki/Special_characters#Racket" rel="nofollow">"Special characters" in Rosetta Code</a>, in section "Racket", mentions:</p>
  
  <blockquote>
    <p>Vertical bars can be used as identifier quotations used around it</p>
  </blockquote>
  
  <p>Is this a bad formulation or can a variable name in Racket actually use a vertical bar somehow? Can someone give an example, please?</p>
  
  <p>Thanks in advance.</p>