title: Foldl on a list of functions in Haskell
body: <p>I'm trying to write a function, <code>pipe</code> that takes a list of mathematical functions where <code>pipe [f1,...,fn] x</code> should return <code>f1(f2(...(fn x)))</code> 
  I've set it up such that:</p>
  
  <pre><code>pipe :: [(a -&gt; a)] -&gt; (a -&gt; a)
  pipe fs   = foldLeft f base fs
    where
      f a x =    
      base  = 
  
  -- &gt;&gt;&gt; pipe [] 3
  -- 3
  --
  -- &gt;&gt;&gt; pipe [(\x -&gt; x+x), (\x -&gt; x + 3)] 3
  -- 12
  --
  -- &gt;&gt;&gt; pipe [(\x -&gt; x * 4), (\x -&gt; x + x)] 3
  -- 24
  </code></pre>
  
  <p>whats the best way to go about this using foldl?
  Thanks!</p>