Adam Flanczewski Slackwise

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

Hofstadter on Lisp

In the mid-80s, while reading through my roommate's collection of Scientific American back issues, I encountered this introduction to Lisp written by Douglas Hofstadter. I found it very charming at the time, and provide it here (somewhat illegally) for the edification of a new generation of Lispers.

In a testament to the timelessness of Lisp, you can still run all the examples below in emacs if you install these aliases:

(defalias 'plus #'+)
(defalias 'quotient #'/)
(defalias 'times #'*)
(defalias 'difference #'-)

npm version cheatsheet

npm uses Semantic Versioning

npm uses Semantic Versioning. Given a version number MAJOR.MINOR.PATCH, increment the:

MAJOR version when you make incompatible API changes,
MINOR version when you add functionality in a backwards compatible manner, and
PATCH version when you make backwards compatible bug fixes.

	const memo = f => {
	let cache = {};
	return (...args) => {
	let key = JSON.stringify(args);
	return cache[key] ?? (cache[key] = f(...args));
	}
	}

	// OLED black smearing test for Processing 3.4.
	// Black smearing = changing pixels to and from pure black is slower than changing to and from other colours.
	//
	// Code by @marcedwards from @bjango.

	void setup() {
	size(360, 360, P2D);
	frameRate(60);
	smooth(8);
	noStroke();

	1. kn0thing
	2. spez
	3. third
	4. fifth
	5. fourth
	6. agentorange
	7. chickenlittle
	8. erzengel
	9. fizzypop
	10. madmax2

	import fs from 'fs';
	import { exec } from 'child_process';

	const compilationConfig = JSON.parse(fs.readFileSync('compilerconfig.json', 'utf8'));

	compilationConfig
	.filter(fileConfig => fileConfig.inputFile.endsWith('.less'))
	.map(({outputFile, inputFile, minify}) => {
	try {
	console.log("LESS\tInput:\t" + inputFile);

	/**
	* Recursively navigates into nested collections inside `collection` by
	* following a sequence of properties `pathArray`, executing any methods
	* along the way, and returning the first `undefined` encountered.
	* @param {any} collection - The collection to traverse.
	* @param {Array<string\|number\|function()>} pathArray - A sequence of
	* property names, indexes, or functions to traverse into the `collection`.
	* @returns {any\|undefined} The final value found,
	* otherwise the first `undefined` encountered.
	* @example

	[General]
	bGamepadEnable=0
	sIntroSequence=0
	bSkipSplash=1
	bDisableAllGore=0
	[Display]
	uiOrthoShadowFilter=3
	bVolumetricLightingEnable=0
	iSize H=1080
	iSize W=1920

	const advise = (fn, preFn = (...args) => args, postFn = (...args) => args) =>
	(...args) =>
	postFn(fn(...preFn(...args)));


	add = (x, y) =>
	x + y;

	advisedAdd = advise(
	add,