Add slurp to list of impure functions

content/cftbat/functional-programming.html

@@ -13,7 +13,7 @@ <h1>Functional Programming</h1>
       <p class="Body">The core concepts you’ll learn include: what pure functions are and why they’re useful; how to work with immutable data structures and why they’re superior to their mutable cousins; how disentangling data and functions gives you more power and flexibility; and why it’s powerful to program to a small set of data abstractions. Once you shove all this knowledge into your brain matter, you’ll have an entirely new approach to problem solving!</p>
       <p class="Body"><span>After going over these topics, you’ll put everything you’ve learned to use </span><span>by writing a terminal-based game inspired by an ancient, mystic mind-</span><span>training</span><span> </span><span>device found in Cracker Barrel restaurants across America: Peg Thing<a id="Anchor"></a>!</span></p>
       <h2>Pure Functions: What and Why</h2>
-      <p class="BodyFirst">Except for <code>println</code> and <code>rand</code>, all the functions you’ve used up till now have been pure functions. What makes them pure functions, and why does it matter? A function is pure if it meets two qualifications:</p>
+      <p class="BodyFirst">Except for <code>println</code>, <code>rand</code> and <code>slurp</code>, all the functions you’ve used up till now have been pure functions. What makes them pure functions, and why does it matter? A function is pure if it meets two qualifications:</p>
       <ul class="List-1">
 	<li class="BulletA">It always returns the same result if given the same arguments. This is called <em>referential transparency</em>, and you can add it to your list of $5 programming terms.</li>
 	<li class="BulletC"><span>It can’t cause any </span><span>side effects. That is, the function can’t make any </span><span>changes that are observable outside the function itself—for example, by </span>changing an externally accessible mutable object or writing to a file.</li>