ArrayRange

[moien007]

In most cases ArrayPool returns an array that its length is bigger than the requested length.
So we usually use ArraySegment but its Offset field is unneeded. So having ArrayRange will be nice.

It already implemented here: https://github.com/aspnet/Blazor/blob/master/src/Microsoft.AspNetCore.Blazor/RenderTree/ArrayRange.cs

[gfoidl]

Do Memory<T> / Span<T> not suffice?

[moien007]

ArrayRange is less complex than Memory<T> and Span<T>. Also Memory<T> contains _index which is (if I'am not wrong) same as ArraySegment<T>.Offset .

[svick]

its Offset field is unneeded

Memory<T> contains _index

Why is that an issue?

[moien007]

Why is that an issue?

If we use Memory<T> with ArrayPool<T>, _index is always zero, isn't it ?
Only difference between ArrayRange and ArraySegment<T> or Memory<T> is Offset or _index removal which makes less stack copy.

[svick]

In that case, do you have a benchmark that shows a realistic scenario (i.e. not a microbenchmark), where using ArrayRange would significantly improve performance?

In other words: if you want to introduce a new API whose sole reason for existing is improved performance, I think you should first show that it actually improves performance.

[moien007]

In that case, do you have a benchmark that shows a realistic scenario (i.e. not a microbenchmark), where using ArrayRange would significantly improve performance?

In other words: if you want to introduce a new API whose sole reason for existing is improved performance, I think you should first show that it actually improves performance.

I don't think ArrayRange give a significant performance improvement, so I'm convinced.