Returns a sorted copy of a deque.
ordf must be a function which can accept any two elements from
deq as arguments.
It must return one of the symbols
> to represent the relative ordering of
those two elements.
If all of the deque's elements are numbers or characters, a good choice for
would be the built-in function
(let sorted (sort "Hello, world!" ord)) (prn sorted) ; prints !,Hdellloorw