JesterXL

var aws = require('aws-sdk');
var sfn = new aws.StepFunctions();

exports.handler = function(event, context, callback) {
  console.log("event:", event)
  console.log("context:", context)
  console.log("callback:", callback)
  let StateMachineArn = event.restart.StateMachineArn;
  event.restart.executionCount -= 1;
  event.AWS_STEP_FUNCTIONS_STARTED_BY_EXECUTION_ID = event.executionID

JesterXL

const getPartsAssemblerStream = s3 => bucket => key => uploadID => {
    const parts = []
    return new stream.Writable({
        objectMode: true,
        write(part, encoding, callback) {    
                                                                                                                                                                                                          
            if(getOr(false, 'isLast', part) === false) {
                parts.push(part)
                callback()

JesterXL

# I always hated Either's name, so changed to Result becuase I like Folktale's better.
from pymonad.Monad import *
from pydash import map_, some, filter_, head, every

class Result(Monad):
	""" 
	Represents a calculation that may either fail or succeed.
	An alternative to using exceptions. 'Result' is an abstract type and should not
	be instantiated directly. Instead use 'Ok' (or its alias 'Ok') and 
	'Error' (or its alias 'Error')

JesterXL

• what is a closure?
• what is a function declaration?
• what is an anonymous function?
• what is a fat arrow function?
• what is Object Oriented Programming?
• what is inheritance?
• What is Object Prototype?
• What is Object.assign?
• What is Object.freeze?
• What is list comprehension?

JesterXL

<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500">
    <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
    <link rel="stylesheet" href="material-components-web-elm.min.css">
    <style>
    @font-face {
        font-family: 'Roboto';
        src: url('Roboto-ThinItalic-webfont.eot');
        src: url('Roboto-ThinItalic-webfont.eot?#iefix') format('embedded-opentype'),
            url('Roboto-ThinItalic-webfont.woff') format('woff'),
            url('Roboto-ThinItalic-webfont.ttf') format('truetype'),

JesterXL

Elm Learning Resources

Elm Tutorial & Guide https://guide.elm-lang.org/

Installing https://guide.elm-lang.org/install.html

Elm Examples

JesterXL

// JavaScript
const fizzAndOrNotBuzz = i => {
    switch(true) {
        case i % 15 === 0: return 'FizzBuzz'
        case i % 5 === 0: return 'Buzz'
        case i % 3 === 0: return 'Fizz'
        default: return i
    }
}

JesterXL

{ resource: '/test-delete-me',
path: '/test-delete-me',
httpMethod: 'GET',
headers: 
{ accept: 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8',
'accept-encoding': 'gzip, deflate, br',
'accept-language': 'en-US,en;q=0.9,es;q=0.8',
'cache-control': 'max-age=0',
Host: 'o8ai4pej00.execute-api.us-east-1.amazonaws.com',
'upgrade-insecure-requests': '1',

JesterXL

'use strict'

const Validation = require('folktale/validation')
const { Success, Failure } = Validation

const {
  isString,
  some,
  identity,
  inRange,

JesterXL

Hard to understand without mastering pure functions, but ok.

tl;dr;

Partial Application is a function where some or all of the arguments are packed inside, ready to go and it's just waiting for a few more before the main function is invoked. They're like functions that have default arguments, but are pure functions with a fixed amount of parameters.

Basic Arguments

The function below pings google.com: const pingGoogle = () => fetch('http://google.com'). If it resolves, Google is there and your computer can talk to the internets. If it throws an error, your computer is probably having wireless trouble.