wayneseymour

Table of Contents

• set -e, -u, -x, -o pipefail
• set -e
• set -x
• set -u
• set -o pipefail
• Setting IFS
• Original Reference

set -e, -u, -x, -o pipefail

wayneseymour

$ git clone [email protected]:xxxxx/xxxx.git my-awesome-proj
Cloning into 'my-awesome-proj'...
ssh: connect to host github.com port 22: Connection timed out
fatal: Could not read from remote repository.

$ # This should also timeout
$ ssh -T [email protected]
ssh: connect to host github.com port 22: Connection timed out

$ # but this might work

wayneseymour

data Parser = WebParser | DbParser

class ParseStrategy p where
  parse :: p -> String -> String

instance ParseStrategy Parser where
  parse WebParser s = "code for parsing web stuff goes here"
  parse DbParser s = "code for parsing db stuff goes here"

fromDB = parse DbParser

wayneseymour

List comprehensions

To see a working version of the code check out https://codesandbox.io/s/j497w26383 and open the console.

This file demonstrates a very basic List as an applicative functor for the purpose of demonstrating a simple list comprehension.

The idea for this was taken from: https://egghead.io/lessons/javascript-list-comprehensions-with-applicative-functors by https://twitter.com/drboolean

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// Finally wrapped your head around Promises? Time to toss out all that knowledge and learn the functional alternative!

// Here's a super simple implementation of a Task "type" 
const __Task = fork => ({fork})

// Absurdly simple! All we're doing is using a function that returns some unknown value, by name, in an object. 
// At this point "fork" is just a cute name though: what matters is how we use it.
// What makes Task a "Task" is that is that the "fork" value here... will be a higher-order function.

// Here's a usage example, already fully functional, already nearly as powerful as Promise!

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// Simple example, but the idea holds for more complex objects.


/* 1) Start with OO */

// user.js
class User {
  constructor(firstName, lastName, email) {
    this.firstName = firstName
    this.lastName = lastName

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const Maybe = {
  Just: value => ({
    value,
    map: f => Just(f(value)),
    toString: () => `Just(${value})`
  }),
  Nothing: (value = null) => ({
    value: null,
    map: f => Nothing(null),
    toString: () => `Nothing(${value})`

wayneseymour

import is from './is-util';

/**
 * Either Monad class (from Functional Programming in JavaScript)
 */
class Either {
  constructor(value) {
    this._value = value;
  }
  get value () {

wayneseymour

import { Observable } from 'rxjs';

// Adapted from https://github.com/Reactive-Extensions/rx-node/blob/87589c07be626c32c842bdafa782fca5924e749c/index.js#L52
export default function fromStream(stream, finishEventName = 'end', dataEventName = 'data') {
  stream.pause();

  return new Observable((observer) => {
    function dataHandler(data) {
      observer.next(data);
    }

wayneseymour

#GNU Screen Cheat Sheet

##Basics

• ctrl a c -> cre­ate new win­dow
• ctrl a A -> set win­dow name
• ctrl a w -> show all win­dow
• ctrl a 1|2|3|… -> switch to win­dow n
• ctrl a " -> choose win­dow
• ctrl a ctrl a -> switch between win­dow
• ctrl a d -> detach win­dow