I am looking for some suggestions on how I can read text files by every n-th file in Raku/perl6.

In bioinformatics research, sometimes we need to parse text files in a somewhat less than straightforward manner. Such as Fastq files, which store data in groups of 4 lines at a time. Even more, these Fastq files come in pairs. So if we need to parse such files, we may need to do something like reading 4 lines from the first Fastq file, and reading 4 lines from the second Fastq file, then read the next 4 lines from the first Fastq file, and then read the next 4 lines from the second fastq file, ......

May I have some suggestions regarding what is the best way to approach this problem? Raku's "IO.lines" approach seems to be able to handle each line one at a time. but not sure how to handle every n-th line

An example fastq file pair: <https://github.com/wtwt5237/perl6-for-bioinformatics/tree/master/Come%20on%2C%20sister/fastq>
What we tried before with "IO.lines": <https://github.com/wtwt5237/perl6-for-bioinformatics/blob/master/Come%20on%2C%20sister/script/benchmark2.p6>