> I think the problem with "drop dup dup × swap abs rot3 dup × swap − +" is that it gets too abstract. Even though it is very elegant and succinct, it takes eff

> I think the problem with "drop dup dup × swap abs rot3 dup × swap − +" is that it gets too abstract. Even though it is very elegant and succinct, it takes effort to understand it. And if something is hard to understand it is also hard to find the errors it may have. But this is my point—the effort it takes to understand it is, in some sense, a one-time effort. If you invest the up-front effort to learn how to read concatenative programs, then you gain a fluency that makes it easier to read other programs. (Our more familiar programming paradigms are just as opaque to a beginning programmer; recursion, which is so fundamentally intelligible to us, is a major obstacle to people first learning to program, but I think there are few who would say it's not worth it.) One of the big goals of concatenative programming is refactorability, which Jtsummers beautifully showed at work in your sibling post: https://news.ycombinator.com/item?id=25261911 https://news.ycombinator.com/item?id=25261911 . If you can understand enough to refactor, then you can simplify it to the point where errors must be apparent.