Why ranges don't return vectors?

[monarch_dodra]

On Friday, 1 March 2013 at 15:38:28 UTC, Piotr Szturmaj wrote:
> Range abstraction is limiting some useful optimizations, mainly 
> vectorization. Even if range internally uses a buffer and does 
> some SIMD operations on it, it exposes only one element from 
> this buffer, which can't be used for next SIMD operation. In 
> other words it limits pipelining.

Well, why don't you write a range whose "elements" are vectors? 
Or that operate on vectors.

The range abstraction only defines how you iterate and view a 
collection. YOU are the one that defines what the elements in 
that collection are.

For example, "chunk" will do exactly that: Given a range, it 
transforms it into a range of sub-slices:

//----
     int[] arr = iota(0, 16).array(); //[0, 1, 2, ..., 16]
     auto chunks = std.range.chunks(arr, 4);
     foreach (int[] chunk ; chunks)
     {
         chunk[] *= 2;
         writeln(chunk);
     }
//----

What else are you asking for? Nothing is stopping you from 
pipping the chunk elements with another range, btw.