title: Get value from IO String in Haskell
body: <p>I have a function with signature <code>read_F95_src :: String -&gt; IO [String]</code>. This function is used elsewhere and cannot be changed.</p>
  
  <p>I am reading in source lines and associated with a label as such <code>src_lines = read_F95_src templ_src_name</code>, which compiles and runs fine.</p>
  
  <p>The problem is that I now have a function which takes in <code>[String]</code>, and no matter how I try, I can't figure out a way to get the <code>[String]</code> value from <code>src_lines</code>.</p>