ssrihari

An opinionated list of excellent Clojure learning materials

These resources (articles, books, and videos) are useful when you're starting to learn the language, or when you're learning a specific part of the language. This an opinionated list, no doubt. I've compiled this list from writing and teaching Clojure over the last 10 years.

• 🔴 Mandatory (for both beginners and intermediates)
• 🟩 For beginners
• 🟨 For intermediates

Table of contents

1. Getting into the language

holyjak

;; A macro to create a decorator (wrapper) for a objects implementing a Java interface
;; Disclaimer: The code most certainly is not perfect and does not handle some corner cases
;; License: The Unlicense http://unlicense.org/
(require '[clojure.string :as str])

(defn type->tag [parameter-type]
  (let [array? (-> parameter-type name (str/ends-with? "<>"))
        primitive? '#{int long float double short boolean byte char}
        type   (if array?
                 (-> parameter-type name (str/replace #"<>$" "") symbol)

leonoel

(ns complex-business-process-example-missionary
  "A stupid example of a more complex business process to implement as a flowchart."
  (:require [missionary.core :as m])
  (:import missionary.Cancelled))

;;;; Config

(def config
  "When set to :test will trigger the not-boosted branch which won't write to db.
   When set to :prod will trigger the boosted branch which will try to write to the db."

didibus

(ns complex-business-process-example
  "A stupid example of a more complex business process to implement as a flowchart.")

;;;; Config

(def config
  "When set to :test will trigger the not-boosted branch which won't write to db.
   When set to :prod will trigger the boosted branch which will try to write to the db."
  {:env :prod})

wcalderipe

Control flow in Clojure

A gist containing a problem example and different implementations based on what is being discussed at How are clojurians handling control flow on their projects?.

Feel free to leave a comment and feedback is welcome 😃

Examples in this Gist

• Bult-in exceptions in a thread macro
• didibus' trylet macro

mmzsource

holyjak

(defn stateful-map
  "Returns a stateful transducer similar to `clojure.core/map-indexed` that
  transforms each item with `(f state <the item>)` where `state` is built by
  applying `state-building-fn` to the previous state (starting with `init`) and
  the transformed item.

  Ex., re-implementing map-indexed:
  ```clojure
  (sequence (stateful-map vector (fn build-state [idx _] (if idx (inc idx) 5))) \"abc\")
  ; => ([nil \\a] [5 \\b] [6 \\c])

cgrand

;; (cond-let 
;;   (odd? x) [x n] (inc x)  
;;   (< n 10) [y (inc n)] 10
;;   :else n))

;; we want the above to yield
;; (let [x n]
;;   (if (odd? x)
;;      (inc x)

btwiuse

;; The deps.edn file describes the information needed to build a classpath.
;;
;; When using the `clojure` or `clj` script, there are several deps.edn files
;; that are combined:
;; - install-level
;; - user level (this file)
;; - project level (current directory when invoked)
;;
;; For all attributes other than :paths, these config files are merged left to right.
;; Only the last :paths is kept and others are dropped.

reborg

Rich Already Answered That!

A list of commonly asked questions, design decisions, reasons why Clojure is the way it is as they were answered directly by Rich (even when from many years ago, those answers are pretty much valid today!). Feel free to point friends and colleagues here next time they ask (again). Answers are pasted verbatim (I've made small adjustments for readibility, but never changed a sentence) from mailing lists, articles, chats.

How to use:

• The link in the table of content jumps at the copy of the answer on this page.
• The link on the answer itself points back at the original post.

Table of Content