title: Replace words in haskell
body: <p>I want to replace full words in text. Type definition is: <code>replace :: [(String, String)] -&gt; String -&gt; String</code>. Function example is:</p>
  
  <pre><code>replace [("fox", "cat"), ("he", "she")] "The quick brown fox jumps over the lazy dog"
  -- result: "The quick brown cat jumps over the lazy dog"`
  </code></pre>
  
  <p>It should be with functions <code>words</code> and <code>unwords</code>. </p>
  
  <p>Do you have any idea? </p>