I'm pretty sure that's "interior" piping to ABS functions like split() and map() As opposed to "exterior" piping to executables like grep and xargs, which may

I'm pretty sure that's "interior" piping to ABS functions like split() and map() As opposed to "exterior" piping to executables like grep and xargs, which may be written in any language I believe the comment you're replying to is saying that's a design MISTAKE And I agree -- in trying to make shell more consistent, you've actually REDUCED its power I wrote a blog post about this issue: Oils Is Exterior-First (Code, Text, and Structured Data) - https://www.oilshell.org/blog/2023/06/ysh-design.html https://www.oilshell.org/blog/2023/06/ysh-design.html (which was aimed at people working on Oils, not general users. Hopefully a more concise/illustrative post will appear, though I also welcome anyone else like the OP who wants to argue this ! )