title: Haskell iterate over a list
body: <p>I know you suppose to think differently in Haskell, but can someone give me a quick answer on how to iterate over a list or nested list and print out a character based on the value of the list element.</p>
  
  <pre><code>list1 = [[1 0 0][0 1 0][0 0 1]]
  </code></pre>
  
  <p>By iterate through this nested list, it should print out x for 0 and y for 1</p>
  
  <pre><code>yxx
  xyx
  xxy
  </code></pre>
  
  <p>Thanks</p>