RangeExtra 10^-20

[dsimcha]

== Quote from Simen Kjaeraas (simen.kjaras at gmail.com)'s article
> dsimcha wrote:
> > RangeExtra version 10^-20 is officially out.  It consists of a small and
> > hopefully growing number of ranges that didn't make it into the new
> > Phobos
> > that I've gotten working reasonably well and I feel eventually belong in
> > Phobos.
> >
> > Docs / What's there:
> > http://cis.jhu.edu/~dsimcha/rangeextra.html
> >
> > Code:
> > http://dsource.org/projects/scrapple/browser/trunk/rangeextra/rangeextra.d
> >
> > License:
> > Dual licensed, Phobos license or BSD (Tango style).
> I had hoped reindex would give me access to true 'random' access ranges, but it
seems this does not work:
>   auto b = reindex!( "uniform( 0, this.length )" )( [0,1,2,3,4].dup );
> :p

Very cool idea.  Nothing like what I had in mind as a use case for Reindex, but
half the fun of generic programming is seeing stuff get used for things you hadn't
anticipated.

I spent some time trying, and for some reason I can't for the life of me get this
example to work, or even the one where the length is hard-coded.  It may be some
obscure compiler bug, because I'm just getting weird inscrutable error messages
and I can't really figure out where they're coming from.

On the other hand, I really like the idea of a with-replacement random sampling
primitive.  This sounds like it belongs in RandomCover.  Maybe Andrei can extend
RandomCover (which already samples w/o replacement) to include a replacement
parameter.  RandomCover w/ replacement == false would do what it does now.  If
replacement == true, it would be an infinite range that samples with replacement.