branneman

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

const Article = require('../../../../app/models/article');

Those suck for maintenance and they're ugly.

Possible solutions

branneman

const { curryN, curry } = require('./curry') // https://gist.github.com/branneman/4ffb7ec3fc4a2091849ba5d56742960c

// Array higher-order
const map = curry((fn, list) => list.map(fn))
const filter = curry((fn, list) => list.filter(fn))
const foldl = curry((fn, init, list) => list.reduce(fn, init))
const foldr = curry((fn, init, list) => list.reduceRight(fn, init))
const find = curry((fn, list) => list.find(fn))
const sort = curry((fn, list) => list.slice().sort(fn))
const includes = curry((fn, list) => list.includes(fn))

branneman

Primitive Types & Reference Types in JavaScript

An explanation of JavaScript's pass-by-value, which is unlike pass-by-reference from other languages.

Facts

• JavaScript has 2 kinds of variable types: primitive and reference.
• A fixed amount of memory is reserved after creation of every variable.
• When a variable is copied, it's in-memory value is copied.
• Passing a variable to a function via a call also creates a copy of that variable.

Primitive Types

branneman

'use strict'

const curryN = (() => {
  const isPlaceholder = x => x['@@functional/placeholder'] === true
  const filterPlaceholders = xs => xs.filter(x => isPlaceholder(x))
  const filterValues = xs => xs.filter(x => !isPlaceholder(x))

  return (arity, fn, accIn = []) => (...args) => {
    const accOut = accIn.slice()

branneman

Software Craftsmanship Katas in Clojure

To run these as-is, you'll need to have Clojure and Leiningen with the lein-exec plugin installed. Then run from the terminal:

git clone https://gist.github.com/258926ff07c85b4e6f5cafc4967740ec.git katas-clojure
cd katas-clojure
lein exec fizzbuzz.clj
lein exec leapyears.clj
lein exec rpn-calculator.test.clj

branneman

const stat = require('fs').statSync;
const AdmZip = require('adm-zip');

/**
 * Example usage
 */
newArchive(`test-${+new Date}.zip`, [
    'index.js',
    'package.json',
    'node_modules'

branneman

British English cheatsheet

In-depth

https://en.wikipedia.org/wiki/Comparison_of_American_and_British_English
https://en.wikipedia.org/wiki/American_and_British_English_pronunciation_differences
https://en.wikipedia.org/wiki/American_and_British_English_grammatical_differences
https://en.wikipedia.org/wiki/American_and_British_English_spelling_differences
https://en.wikipedia.org/wiki/Lists_of_words_having_different_meanings_in_American_and_British_English

Pronunciation

branneman

var net = require('net');

//
// Client
//

function openSocket() {
    var socket = net.connect(3e3);
    socket.setKeepAlive(true);
    socket.on('connect', onConnect.bind({}, socket));

branneman

// FP Lenses
const lens = get => set => ({ get, set });
const view = lens => obj => lens.get(obj);
const set = lens => val => obj => lens.set(val)(obj);
const over = lens => fn => obj => set(lens)(fn(view(lens)(obj)))(obj);
const lensProp = key => lens(prop(key))(assoc(key));

branneman

const fl = require('fantasy-land')
const inspect = require('util').inspect.custom

// Fantasy Land
//  of :: Applicative f => a -> f a
//  map :: Functor f => f a ~> (a -> b) -> f b
//  ap :: Apply f => f a ~> f (a -> b) -> f b
//  chain :: Chain m => m a ~> (a -> m b) -> m b

/**