It's totally unclear to me which kind of problem you are trying to solve with the sliding window.

Or if you are just interested to play around with iterators.

Point is that realizing a solution to the example I gave, i.e. to search a huge file with a regex doesn't seem trivial with the module you chose.

The documentation mentions a file iterator but it's operating on record separators not on fixed size chunks.

Hence you'd need to generate a chunk iterator, which masks as a tied "lazy" array.

But do you really need to solve THIS problem?