tjmw

require 'json'

class MyApp
  def call(env)
    request = Rack::Request.new(env)
    headers = {
      'Content-Type' => 'application/json',
      'Access-Control-Allow-Origin' => '*',
    }

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TAX_RATE = 0.4
BENEFIT_COST = 1000

SALARY_IN_PENCE = 15_000 * 100

subtract_benefit = ->(salary) { salary - BENEFIT_COST }
pay_tax = ->(salary) { salary * (1 - TAX_RATE) }

calculate_take_home_pay = subtract_benefit >> pay_tax
puts "Pre-tax benefit: #{calculate_take_home_pay.call(SALARY_IN_PENCE)}"

tjmw

import React, { Component } from "react";
import logo from "./logo.svg";
import "./App.css";

const apiSendMessage = message =>
  new Promise((resolve, reject) => {
    const randomDelay = Math.floor(Math.random() * 3000);

    setTimeout(() => {
      const isSuccessful = Math.floor(Math.random() * 10) % 2 == 0;

tjmw

// @flow

class PromiseRetryer {
  fn: () => Promise<*>;
  maxTryCount: number;
  retryDelay: number;
  tries: number;

  constructor(fn: () => Promise<*>, maxTryCount: number, retryDelay: number) {
    this.fn = fn;

tjmw

Elm Building Blocks

An introduction to a few FP concepts with Elm.

Currying

Functions are curried by default in Elm.

From Wikipedia: "the technique of translating the evaluation of a function that takes multiple arguments (or a tuple of arguments) into evaluating a sequence of functions, each with a single argument".

tjmw

class Result
  def initialize(operation, failure_test, *args)
    @operation = operation
    @failure_test = failure_test
    @args = args
  end

  def and_then(next_operation)
    if failure_test.call(result)
      self

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class FakeRecord
  # ActiveModel plumbing to make `form_for` work
  extend ActiveModel::Naming
  include ActiveModel::Conversion
  include ActiveModel::Validations

  attr_accessor :foo, :bar

  validates :foo, presence: true

tjmw

highlight -O rtf order.rb --font-size 36 --style navajo-night | pbcopy

tjmw

find spec/renderers/ -type f -name '*.rb' -exec perl -p -i -e "s/loadPage\(\'(.*?)\'\)/loadPage('\1?client_bundle=abcde')/g" {} +

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/**
 * Simple event dispatcher
 *
 * Example
 *
 * var MyConstructor = function () {
 *    var self = this
 *    var count = 0
 *    setInterval(function () {
 *      self.emit('tick', {count: count})