Derick Warshaw derickwarshaw

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

What's an Effective Engineer?

Intro

This is a basic collection of things I do when setting up a new headless ubuntu machine as a webserver. Following the steps below should give you a reasonable secure server with HTTP/2 support (including ALPN in chrome) and the fast NGINX server. I am happy to add things so leave a comment.

Basics

After creating the server (droplet on DigitalOcean) log in with

	const md5File = require('md5-file');
	const path = require('path');

	// CSS styles will be imported on load and that complicates matters... ignore those bad boys!
	const ignoreStyles = require('ignore-styles');
	const register = ignoreStyles.default;

	// We also want to ignore all image requests
	// When running locally these will load from a standard import
	// When running on the server, we want to load via their hashed version in the build folder

	const { introspectSchema } = require("apollo-codegen");
	const { executeWithOptions } = require("graphql-code-generator/dist/cli");
	const fs = require("fs");
	const path = require("path");

	const graphqlPath = "./src/graphql/";
	const schemaInput = "./src/graphql/temp.graphql";
	const jsonOutput = "./src/graphql/temp.json";
	const dtsOutput = "./src/graphql/domain.d.ts";

	// This is used to access the state of the wrapped instance.
	// It can be done with a 'ref' but this would incur an extra render cycle.
	import { withRouter } from 'react-router';

	const DEFAULT_WARNING = 'You have unsaved changes, are you sure you want to leave?';

	export default ({
	warningMessage = DEFAULT_WARNING,
	unsavedChangesMethod
	}) => (WrappedComponent) => {

	/******************************************************************************/
	'use strict';
	/******************************************************************************/
	// via https://twitter.com/bmeurer/status/821804688454680576

	console.log(`
	// v8 ${process.versions.v8} (Node.js ${process.versions.node})
	`);

	function forVar_______(a) {

	// Usage:
	//
	// function loader() {
	// return new Promise((resolve) => {
	// if (process.env.LAZY_LOAD) {
	// require.ensure([], (require) => {
	// resolve(require('./SomeComponent').default);
	// });
	// }
	// });

	{
	"swagger": "2.0",
	"info": {
	"title": "Passkit Web Service",
	"contact": {
	"name": "Clemens Krack",
	"email": "info@clemenskrack.com"
	},
	"version": "1.0.0"
	},

	{
	// http://eslint.org/docs/rules/

	"ecmaFeatures": {
	"binaryLiterals": false, // enable binary literals
	"blockBindings": false, // enable let and const (aka block bindings)
	"defaultParams": false, // enable default function parameters
	"forOf": false, // enable for-of loops
	"generators": false, // enable generators
	"objectLiteralComputedProperties": false, // enable computed object literal property names