On Thu, Feb 28, 2013 at 09:20:52PM +0100, Andrea Fontana wrote:
> On Thursday, 28 February 2013 at 18:23:04 UTC, H. S. Teoh wrote:
[...]
> >auto triangularProduct2(R1,R2)(R1 r1, R2 r2)
> > if (isForwardRange!R1)
> >{
> > return map!(function(a) => zip(take(a[1].save, a[0]),
> >repeat(a[2])))(
> > zip(sequence!"n"(1), repeat(r1.save), r2)
> > )
> > .joiner();
> >}
> >
> >As above, both ranges can be infinite, only the first one needs to
> >be a
> >forward range.
> >
> >Hope this helps. ;-)
> >
> >
> >T
>
> triangulaProduct2 for [0,1,2,3] and [0,1,2,3] doesn't give (0,0)
> (1,1) (2,2) (3,3)
>
> :)
Ahhh, slight mistake there, it should be:
auto triangularProduct2(R1,R2)(R1 r1, R2 r2)
if (isForwardRange!R1)
{
return map!(function(a) => zip(take(a[1].save, a[0]+1), repeat(a[2])))(
zip(sequence!"n"(1), repeat(r1.save), r2)
)
.joiner();
}
There, better now? ;-)
Also, if you only need products of finite ranges, it's possible to
rewrite it so that it produces items in a nicer order. The strange order
output by my examples are to cater for the infinite case.
T
--
Life would be easier if I had the source code. -- YHL
