title: Getting and removing the first character of a string
body: <p>I would like to do some 2-dimensional walks using strings of characters by assigning different values to each character.  I was planning to 'pop' the first character of a string, use it, and repeat for the rest of the string.</p>
  
  <p>How can I achieve something like this?</p>
  
  <pre><code>x &lt;- 'hello stackoverflow'
  </code></pre>
  
  <p>I'd like to be able to do something like this:</p>
  
  <pre><code>a &lt;- x.pop[1]
  
  print(a)
  
  'h'
  print(x)
  
  'ello stackoverflow'
  </code></pre>