enforser

;; Unlike fully lazy languages such as Haskell, Clojure seqs often implement chunking.
;; This means that when accessing the first element of a sequence, 32 members will be evaluated.
;; An example of this can be seen by implementing some side effect in a map.

(first (map (fn [x] (prn x) x) (range 5))) ;; prints 0 through 4, then returns 0

;; The above example will return 0 (as expected), but you'll notice it prints off all 5 elements
;; of (range 5).
;; In the next case we can see that the evaluation caused by the access of the first element stops after
;; the first 32 elements are evaluated.

enforser

;; Demonstrates the usage of vars that are useful when working in the REPL.
;; Created: November 14, 2018
;;
;; My suggested method of reading this file is to copy it into some project and actually
;; go through the code snippets and evaluate in the REPL to play around with them. 
;;
;; WARNING: Some of the examples will create a file called 'output.txt' from the directory 
;;          that your REPL is started in.
;;
;;

enforser

;; This document is meant to demonstrate a common misunderstanding in how
;; clojure.async's go blocks handle parallel processing.

(require '[clojure.core.async :as a])

;; non-blocking core async example.
(time (let [n 1000
            vals-coll (atom [])]
        (let [pipeline-chan (a/chan 1)]
          (dotimes [i n] (a/go (a/>! pipeline-chan i)))

enforser

;; I use these when I want to throw a lot of `time` functions into code, 
;; as it allows me to append a log to it. Using log-time-str I can 
;; pass the str to whatever logging library I'm using at the time, 
;; to achieve any benefits from that. 

(defmacro log-time
  "prints msg and the approximate number of milliseconds it took to
  eval the given expression. Returns the result of the expr."
  [msg expr]
  `(let [start-time# (System/nanoTime)

enforser

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  * I have a public key ASAA7YHJZ-i09gJFWLxJKP2fUwHfgfFpu0GbvgvXvGYCcAo

To claim this, I am signing this object: