title: Replace a substring from a string in Haskell
body: <p>I have the following string <code>"not really//"</code> and I want to write a function that replaces every two slashes <code>"//"</code> with two dots <code>".."</code></p>
  
  <p>I thought about using map, but then I would iterate through characters and can't know if a slash is going to be followed by another or not. Any clue how this can be done? (without regex)</p>