Range Type

[Koroskin Denis]

On Mon, 24 Mar 2008 14:12:15 +0300, Janice Caron <caron800 at googlemail.com>  
wrote:

> I know this has cropped up before (in discussions about multiple
> dimension arrays), but adding a range type would also really help with
> the whole business of returning slices. (See the many other threads
> currently buzzing with this topic).
>
> A range is nothing more than a two-element struct
>
>     struct Range(T,U=T)
>     {
>         T begin;
>         U end;
>     }
>
> However, if you throw in some extra language support, it gets really,
> really useful. Basically, you want the ".." infix operator always to
> create a range. Thus
>
>     auto x = 3 .. 4;
>
> creates a Range!(int) with values { 3, 4 }. In general (a .. b) should
> evaluate to a Range!(typeof(a),typeof(b)) with values { a, b }.
> Finally, you also want [] and opSlice() to accept Range! parameters,
> so that
>
>     s = s[a..b];
>
> can always be rewritten as
>
>     auto t = a..b;
>     s = s[t];
>
> In general, opSlice(Range r) should be eqivalent to opSlice(r.begin,  
> r.end).
>
> In my opinion language support for ranges (allowing .. to return a
> range, and allowing [] to accept a range) has advantages above and
> beyond those already discussed, and may also allow many other exciting
> possibilites we haven't even thought of yet.

Yeah, built-in Ranges are great! Where do I vote for them? :)