In practice, I hear people talking about "disjoint" sets all the time—it comes up a lot more often than "overlapping" or "not overlapping". It might have a negative in the name semantically, but it's used as an atomic word in practice. (That is, when people say "disjoint" they're *thinking* "disjoint" as opposed to "not joint" or "not overlapping".) I'm in favor of naming functions with common usage in mind, and I think "disjoint" is the word people use most often in this context. On Tue, Dec 19, 2017 at 7:44 AM, Henning Thielemann < lemming@henning-thielemann.de> wrote:
On Tue, 19 Dec 2017, Víctor López Juan wrote:
I'm thinking that `disjoint` is already a negation:
(dis- (not) + joint (united)). When composing with `not`, the user gets a double negation `not (disjoint x y)`. There is a then a small mental effort required to go from "not disjoint" to "overlapping".
If we are going to have only one of the two properties, I would rather have the positive one (`overlaps`) as primitive. Then `disjoint` would be written "not (overlaps x y)", which reads quite easily. (Or even "not (x `overlaps` y)").
I also dislike double negation and think that 'disjoint' is one. I'd prefer to see both 'overlap' and 'disjoint'. _______________________________________________ Libraries mailing list Libraries@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries