I don't know. Thanks for the implicit compliments and all, but it's an awfully specific set of circumstances, not a general performance analysis even of VCF never mind DSV parsing. The performance will be closely related to how long various column substrings are. That will be specific to the data I just made up from a sample file to have something reproducible by others. Someone with real data files like @markebbert would be in a better position to say something interesting about VCF parsing. { I also continue to agree with Araq that for this kind of situation it would be better if someone who's read that PDF which I linked to more thoroughly than I did (or want to) wrote some careful VCF parser API in Nim. }
So, I'm not sure what the post would be "about" exactly except perhaps some implicit performance one-upsmanship of [https://nim-lang.org/blog/2017/05/25/faster-command-line-tools-in-nim.html](https://nim-lang.org/blog/2017/05/25/faster-command-line-tools-in-nim.html). Such one-upsmanship is often an almost never ending game of diminishing returns and benchmark debates that I don't have time/inclination to pursue further at this moment. Also, it's just code outside the stdlib anyway. Feels a little like someone else's yard to me rather than some specifically Nim-conventional way to do something. `cols.nim` is already small 45-line example program, and the above snippet even smaller. But by all means, if you or Kaushal want to write more about it and link back here then you should! - cheers