praeclarum

module AlgorithmW

// HINDLEY-MILNER TYPE INFERENCE
// Based on http://catamorph.de/documents/AlgorithmW.pdf
// (Now at http://web.archive.org/web/20170704013532/http://catamorph.de/documents/AlgorithmW.pdf)

type Lit =
    | LInt of int
    | LBool of bool

nkpart

fmap . fmap . fmap

Functors and Traversables compose.

You might have seen this statement before. This is how you can take advantage of it.

Composing many fmap calls gives you a function that will drill down into a structure and modify it at a certain depth in that nested structure.

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

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aktowns-4clojure-solution22.clj

;; aktowns's solution to Count a Sequence
;; https://4clojure.com/problem/22

(fn [x] (reduce #(+ %1 %2) (map (fn [_] 1) x)))