Slackwise

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 #'-)

Slackwise

npm version cheatsheet

npm uses Semantic Versioning

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

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

Slackwise

// 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();

Slackwise

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

Slackwise

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);

Slackwise

/**
 * 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

Slackwise

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

Slackwise

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


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

advisedAdd = advise(
  add,

Slackwise

using System;
using System.ComponentModel;
using System.Reflection;
using System.Windows.Data;

public class EnumBindingSourceExtension : System.Windows.Markup.MarkupExtension
{
    private Type _enumType;
    public Type EnumType
    {

Slackwise

const numbers    = document.body.textContent.trim().split('\n').map(Number);
const set        = new Set(numbers);
const goalSum    = 2020;
const difference = n => goalSum - n;
const subtrahend = numbers.find(n => set.has(difference(n)));
const minuend    = difference(subtrahend);
const product    = subtrahend * minuend;
console.log(product);