luddite.js

hey CampJS VIII

i'm Mikey (@ahdinosaur) from Enspiral

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slides are available at http://dinosaur.is/campjs-viii-ludditejs.

???

second time presenting at a conference.

apologies in advance if i disguise any opinions as facts.

what?

this talk is a mashup of a few topics:

• why you only need simple functions and objects to build complex systems
• why the best modules should not have any added sugar
• how "mad science" led to the success of Node.js and thus JavaScript
• why TC39 (the committee behind ES6+) is bad for JavaScript
• why you should ignore "modern JavaScript" (promises, classes, async / await, generators, and beyond).

first, some simplified history...,

2009

nobody cares about JavaScript

it's a toy language

Ryan Dahl (@ry) creates Node.js

watch the original presentation

To provide a purely evented, non-blocking infrastructure to script highly concurrent programs.

(original website here)

???

// core-less node? https://github.com/nodejs/node/issues/7098
// https://github.com/nucleus-js/design

function

function (...args) {
  return value
}

module

here's the CommonJS module system, as used and popularized by Node.js

// cat.js
require('cat-names').random

// cat-loop.js
const cat = require('./cat')

setInterval(() => {
  console.log(cat())
})

the module wrapper

every module is actually wrapped in a closure

(function (exports, require, module, __filename, __dirname) {
  // your module code actually lives in here
})

how require works

When you call require('some_module') in node here is what happens:

1. if a file called some_module.js exists in the current folder node will load that, otherwise:
2. node looks in the current folder for a node_modules folder with a some_module folder in it
3. if it doesn't find it, it will go up one folder and repeat step 2

This cycle repeats until node reaches the root folder of the filesystem, at which point it will then check any global module folders (e.g. /usr/local/node_modules on Mac OS) and if it still doesn't find some_module it will throw an exception.

the Node aesthetic

• Callback austerity: Simplicity, asyncronous nature and nice additions that are included like the event system.
• Limited surface area: Using modules instead of extending them, NPM, re-usable interfaces and simple, consistent function calls.
• Batteries not included: Only few modules in the core distribution – reduces clutter, version dependencies and bureaucracy.
• Radical reusability: Breaking up a problem in small pieces, NPM module locations, great versioning approach

factory

“The problem with object-oriented languages is they’ve got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle.” ~ Joe Armstrong

• The Two Pillars of JavaScript Part 1: How to Escape the 7th Circle of Hell
• stampit

???

TODO two ways of handling errors: throw err and cb(err) how it's important to throw 'programmer errors'

callback

• run-series
• run-parallel
• run-auto
• run-waterfall

continuable

a "continuable" is a function that takes a single argument, a node-style (error-1st) callback.

const continuable = (cb) => {
  // do stuff...
  cb(err, data)
}

• continuable
• cont

observable

• thing() gets the value
• thing.set(...) sets the value
• thing(function (value) { ... }) listens to the value.

• observ
• observable
• push-stream
• mutant

stream

• pull-stream
• pull streams
• pull-stream-examples

references

• es2040
• Art of Node
• Art of I/O
• Tiny Guide to Non Fancy Node

???

TODO luddite.js apps:

• https://webtorrent.io/
• http://standardjs.com/
• https://peermaps.github.io/
• http://loopjs.com/
• https://scuttlebot.io/
• https://choo.io/