[swift-evolution] About the PermutationGenerator

[Dmitri Gribenko]

On Thu, Dec 31, 2015 at 3:36 PM, Susan Cheng <susan.doggie at gmail.com> wrote:
> I don't think so.
>
> As we don't say "Fibonacci collection", we know Fibonacci numbers are in
> order. But we can't tell the number immediately if I asked a specific index
> of Fibonacci sequence. The only way is calculate the sequence one by one
> from start.

That's OK, collections can have Forward indices which have exactly
these properties.

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/