Looks like the equivalents of `-?>` and `-?>>` are now `some->` and `some->>`, is that right? Perhaps the name change is meant to avoid confusion now that there are multiple variants, i.e. also `cond->` and `cond->>`, which are different.

It also occurs to me that threading through `some->` and `some->>` is kind of like doing computations in the Maybe monad in Haskell.