Convert a string representing a binary number to a base 10 string haskell

Question

I have the string \"1001\" and I want the string \"9\".

The numeric library has the (rather clunky) showIntAtBase, but I haven\'t been able to find the opposite.

Answer 1

binario :: Int -> [Int]                      
binario 1 = [1]                  
binario n = binario(div x 2)++(mod n 2:[])

credits to @laionzera