title: Couldn't match expected type [Int] Haskell
body: <p>I am new to Haskell so I don't quite understand most of its errors. I have encountered an error trying to make a higher order function that uses <code>foldl()</code> to read a list and then multiply it by 2 (it automatically reverses it) and I use another another <code>foldl()</code> just to read it, in so reversing it to its original order.</p>
  <p>I would be thankful for any help I receive.</p>
  <p><strong>here's the error</strong></p>
  <pre><code> • Couldn't match expected type ‘[Int]’
                    with actual type ‘t0 Integer -&gt; [Integer]’
      • Probable cause: ‘foldl’ is applied to too few arguments
        In the first argument of ‘reverses’, namely
          ‘(foldl (\ acc x -&gt; (2 * x) : acc) [])’
        In the expression: reverses (foldl (\ acc x -&gt; (2 * x) : acc) [])
        In an equation for ‘multthr’:
            multthr = reverses (foldl (\ acc x -&gt; (2 * x) : acc) [])
     |
  16 | multthr = reverses(foldl(\acc x-&gt; (2*x):acc)[])
     |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  </code></pre>
  <p><strong>here's the source code</strong></p>
  <pre><code>reverses::[Int] -&gt;[Int]
  reverses = foldl(\acc x-&gt; x:acc)[]
  
  multthr::[Int]-&gt;([Int]-&gt;[Int])
  multthr = reverses(foldl(\acc x-&gt; (2*x):acc)[]) 
  </code></pre>