Example signature:

extension IterableWindows<T> on Iterable<T> {
  Iterable<List<T>> windows(int size) sync* {
    ...
  }
}

Given the following call:

final list = [1, 2, 3, 4, 5];
final size = 2;

print(list.windows(size));

windows() produces a list of slices, where every slice is of size size, and where every consecutive slice begins one element later:

[[1, 2], [2, 3], [3, 4], [4, 5]]

Notes:

• The number of produced windows is equal to list.length - (size - 1).
  • So, given a list of length 4 and window size 2, there would be 3 windows.

Constraints:

• size must be a positive, non-zero integer.
• size must not exceed the length of list.

If accepted, I'd be happy to implement this myself!