C#8 introduced support for ranges using ... For example:

var middle = array[1..^1];

The array bounds can also be computed:

var moreMiddle = array[start..(start+numItems)];

We would have to support new overloads for collection methods that take Range parameters.

More details on the syntax can be found here:

https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/member-access-operators#range-operator-