Reading over many of the comments here makes me sad. Many of them seem to be about what I, the developer, can use. Let me reframe it — what if you thought of

Reading over many of the comments here makes me sad. Many of them seem to be about what I, the developer, can use. Let me reframe it — what if you thought of FP techniques as something you could expose to a user of your API? What if you viewed all your work in a language as a language. Borrowing concepts like affine types (aha, rust!), dependent types (hello, Agda!), composition (from pipes to combinators, this one is everywhere!) is important. Strictly procedural or OO concepts might be useful in an implementation, but it rarely helps the user.