Oliver Turner oliverturner

New computer setup

a/o 2020-05-29

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Format the drive

Restart with Cmd-R or Cmd-D
Erase drive / 3x if second-hand
Reinstall MacOS

This tutorial uses the "Sample hapi.js REST API" project.

Take a look at: https://github.com/agendor/sample-hapi-rest-api/

##Topics

Introduction
Installing Node.js
Installing MySQL
Setting-up the project

Service Worker - offline support for the web

Progressive apps - high-res icon, splash screen, no URL bar, etc.

Progressive Web Apps: Escaping Tabs Without Losing Our Soul

Distilling the Essence of Reducers

Redux has brought the notion of reducer back into the awareness of many developers for whom they are a novel concept. In fact they are quite simple, and used all the time in such things as SUM aggregations in databases, where they compute a single value from many.

It's great that Redux has made reducers known to a broader audience, though they are relatively ancient concepts in programming, in fact. But the particular way Redux illustrates a reducer in its documentaion is, in my opinion, with a coding style that is harder to extend and read than it should be. Let's distill reducers down to their essensce, and build up Redux reducers in a way that lowers complexity, and helps separate Redux idioms from your business logic.

The simplest reducer

A reducer is a pure function that accepts more arguments than it returns. That is to say - one whose "arity" is greater than 1. It 'reduces' the two things you pass it down to a single value. Here are two reducers, in a map

	'use strict';

	var babel = require('babel-core');
	var fs = require('fs');

	// borrowed from https://github.com/babel/babel-jest/blob/master/index.js
	require.extensions['.jsx'] = function (module, filename) {
	var src = fs.readFileSync(filename, 'utf8');
	// Allow the stage to be configured by an environment
	// variable, but use Babel's default stage (2) if

	// promise
	const sleep = (timeout, v) => new Promise(r => setTimeout(() => r(v), timeout));
	// series to call
	const series = [() => sleep(1000, 1), () => sleep(1000, 2), () => sleep(1000, 3)];

	// serialize
	const r = series
	.reduce(
	(m, p) => m.then(v => Promise.all([...v, p()])),
	Promise.resolve([])

	import { combineReducers } from 'redux';
	import users from './reducers/users';
	import posts from './reducers/posts';

	export default function createReducer(asyncReducers) {
	return combineReducers({
	users,
	posts,
	...asyncReducers
	});

	if (typeof Promise === 'undefined') {
	require.ensure([], (require) => {
	require('imports?this=>window!es6-promise')
	})
	}

	if (typeof fetch === 'undefined') {
	require.ensure([], (require) => {
	require('imports?self=>window!whatwg-fetch')
	})

	# ...

	[options]
	# webpack loaders
	module.name_mapper='.*\.css$' -> '<PROJECT_ROOT>/flow/stub/css-modules.js'
	module.name_mapper='.*\.\(svg\\|png\\|jpg\\|gif\)$' -> '<PROJECT_ROOT>/flow/stub/url-loader.js'

	export const refreshFrequency = 1000;
	export const command = `ps axro \"%cpu,ucomm,pid\" \
	\| sed -e 's/^[ \\t]//g' -e 's/\\([0-9][0-9]\\.[0-9][0-9]\\)\\ /\\1\\%\\,/g' -e 's/\\ \\ \\([0-9][0-9]$\\)/\\,\\1/g' -e's/\\ \\ /\\_/g' \
	\| awk 'FNR>1' \
	\| head -n 3 \
	\| awk -F',' '{ printf \"%s,%s,%d\\n\", $1, $2, $3}' \
	\| sed -e 's/\\_/\\ /g'`;


	const style = {