A little of coordination for Rosettacode

[ixid]

On Tuesday, 19 March 2013 at 18:53:21 UTC, bearophile wrote:
>> Small changes on your version:
>> http://codepad.org/E9KHKvAi
>
> It's now on Rosettacode. I have added more changes to make it 
> able to deal with immutable input.
>
> Bye,
> bearophile

Another issue to consider as the question I was attempting ended 
up requiring this, I wasn't aware of it when I made the original 
post:

The prime factorization of 1 is an empty set, so surely to be 
correct it should return [] when given 1 and not throw an 
exception. This also suggests a possible modification to 
[].reduce!"a * b" as mathematically the product of the empty set 
is defined as 1.