ChrisMarshallNY

Keybase proof

I hereby claim:

• I am chrismarshallny on github.
• I am chrismarshallny (https://keybase.io/chrismarshallny) on keybase.
• I have a public key ASA9qgqTBewdJkOVIqdYblw88MkJ0bQoBEjYQDebihAcMQo

To claim this, I am signing this object:

ChrisMarshallNY

// This is the little demo, at the start.
protocol A {
    var thisIsRequired: String { get }
    var thisIsOptional: String { get }
}

extension A {
    var thisIsOptional: String { get { "" } set {} }
}

ChrisMarshallNY

/*
 PLAYGROUND 0: Runtime Information Example
 
 ©2019 Rift Valley Software. All Rights Reserved.
 */

func printInfo(_ inVal: Any) {
    print("\n\tValue of Parameter:")
    print("\t\tSimple Value         : \(inVal)")
    print("\t\tSelf                 : \(inVal.self)")

ChrisMarshallNY

/*:
 # FUNCTION TYPES AND PARAMETER NAMES
 
 [This is the Apple Page on Functions](https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/Functions.html)
 */

//: First, we define a function with explicitly named parameters.
func thisIsABasicFunction(with: Int, and: Int) {
    print("\(with), \(and)")
}

ChrisMarshallNY

//: Ranges (Open-Ended) can be empty
let rangeIsEmpty = (0..<0).isEmpty
//: ClosedRanges cannot be empty.
let closedRangeIsEmpty = (0...0).isEmpty

//: This will cause a nasty error. Uncomment to see the error.
//let downwardSpiral = 1...0
//: Same here (which makes sense).
//let downwardSpiral = 1..<0

ChrisMarshallNY

/*
 # ENUMS
 
 Here, we'll play with associated value enums.
 
 The scenario is an error reporting system.
 
 We have multiple classes of errors, and, within those classes, specific errors.
 
 We have a localized error string, and a universal error code for each specific error.

ChrisMarshallNY

var count = 0

print("\nSimple Closure (No capture list):\n")
let closure = {print("count is \(count)")}
for counter in 0..<5 {
    count = counter
    closure()
}

var optionalCount: Int! = 0

ChrisMarshallNY

var externalContextVariable: Int = 5

// These are errors
//let closure = {[inout externalContextVariable] () -> Void in
//let closure = {[var externalContextVariable] () -> Void in

let closure = {[externalContextVariable] () -> Void in
// This is an error.
//    externalContextVariable = 6
    print("externalContextVariable is \(externalContextVariable)")

ChrisMarshallNY

import CoreLocation

// Pretend this Dictionary is the result of parsing a "Localizable.strings" file.
// In this case, we are translating from Engineering to Marketing.
let g_localized_strings: [String: String] = [
    "This app's infested with bugs.": "This app's loaded with features!",
    "What you are asking for is impossible.": "We'll have this ready for beta-testing in a month!",
    "This project is a nightmare.": "This is the project that I've been dreaming of!",
    "This schedule is completely unrealistic.": "This sounds like a fascinating challenge!"
]

ChrisMarshallNY

// Now, as of Swift 2, you can add "default vars and funcs" to protocol extensions:
protocol EmojiString {
    var poopEmoji: String { get }
    var waterEmoji: String { get }
    var smileyEmoji: String { get }
}

extension EmojiString {
    var poopEmoji: String { return "\u{1F4A9}" }
    var waterEmoji: String { return "\u{1F30A}" }