chefnobody

https://www.youtube.com/watch?v=A0VaIKK2ijM

SEPARATION OF EFFECTS FROM PURITY

Part 1:
Isolation of side-effects

An expression is said to have a side-effect if its execution makes an observable change to the outside world.

The goal is to make side-effects understandable, not make them go away.

chefnobody

import Combine
import PlaygroundSupport
import UIKit

/// A line by line walk through of the following Combine example:
/// https://useyourloaf.com/blog/getting-started-with-combine/

class TermsOfUseViewController: UIViewController {
    
    // Some state:

chefnobody

import PlaygroundSupport
import UIKit

/// A line by line walk through of the following Combine example:
/// https://useyourloaf.com/blog/getting-started-with-combine/

class TermsOfUseViewController: UIViewController {
    
    // Some state:
    private var acceptedSwitch1: Bool = false {

chefnobody

/*
 Write a function that takes an expression and evaluates it. The expression is a different notation of an operand working over two operands. For example:
 "2 + 5", in this prefix expression language could be written "(+ 2 5)"
 
 The grammar for this expression syntax works like so:
 
 
 expression := "( operator operand operand )"
 operator: "*" | "+"
 operand: expression | integer

chefnobody

lsof -n -i4TCP:3000

# source:
# https://blog.jayway.com/2012/09/08/finding-the-pid-listening-on-a-specific-port-on-mac-os-x/

chefnobody

//: Playground - noun: a place where people can play

import Foundation

protocol SendDataDelegate: class {}

// Only need to use "weak" if the delegate is of type `class`? structs and enums are value types, not reference types so they don't create retain cycles.
class SendingVC {
  weak var delegate: SendDataDelegate?  // Remove "weak" and you create a strong reference between both these *VC objects
}

chefnobody

import Foundation

func gcd(_ a:Int, _ b:Int) -> Int {
    let r = a % b
    if r != 0 {
        return gcd(b, r)
    } else {
        return b
    }
}

chefnobody

//: Playground - noun: a place where people can play

import UIKit
import PlaygroundSupport

private final class ProgressLayer: CALayer {
    @NSManaged var progress: CGFloat
    
    private let fillColor = UIColor.blue.cgColor
    

chefnobody

//: Playground - noun: a place where people can play
// Inspiration: http://cslibrary.stanford.edu/110/BinaryTrees.html

import UIKit

var values = [10, 5, 6, 8, 9, 22, 3, 2, 4, 7, 14]

class Node {
    var value:Int = 0
    var left:Node? = nil

chefnobody

//: Playground - noun: a place where people can play

import Foundation
import UIKit

func fib(_ n: Int) -> Int {
    if n == 0 { return 0 }
    if n == 1 { return 1 }
    return fib(n - 1) + fib(n - 2)
}