[Haskell-beginners] randomize the order of a list

[Felipe Lessa]

On Sat, Aug 28, 2010 at 10:49 AM, A Smith <asmith9983 at gmail.com> wrote:
> I've abeen recommended on good authority(my son, a Cambridge Pure maths
> graduate, and Perl/Haskell expert) , and backed by a Google search that
> Fisher-Yates shuffle is the  one to use, as it produces total unbiased
> results with every combination equally possible.
> As with most things with computers,don't reinvent the eheel, it's almost
> certainly been done before by someone brighter that you, Fisher,Yates. &
> Knuth!

That shuffle requires O(n) time and O(1) space for arrays.  Here we're
dealing with lists, so either you copy everything between lists and
array or use another algorithm.

Cheers!

-- 
Felipe.