kengruven

// GOALS:
// 1. Two protocols, BasicNode and SpecialNode.
// 2. They both have "var children: Array<...>", so there's an easy way to walk the tree.
// 3. You can build a tree out of parent->child links from:
//    - BasicNode -> BasicNode
//    - BasicNode -> SpecialNode
//    - SpecialNode -> SpecialNode
// (but never SpecialNode -> BasicNode).

// Is it possible to define this structure in Swift?

kengruven

struct S {
    init() { }
}

let s = S()

protocol P {
    func f<T>() -> [T]
}

kengruven

func inc(_ x: Int) -> Int {
    return x + 1
}
func inc(_ x: Int, by y: Int = 3) -> Int {
    return x + y
}

// how does it decide which one to call?
// in this case, it picks the shorter / exact type match:
inc(3)

kengruven

enum Real {
    case notANumber
    case positiveInfinity
    case negativeInfinity
    case floatingPoint
}

func ~=(pattern: Real, value: Double) -> Bool {
    switch pattern {
    case .notANumber:       return value.isNaN

kengruven

// run "xcrun swift", and paste these 3 statements:
enum B {
    case x(String)
}
struct A {
    let b: B
}
let a = A(b: .x("a"))  // (not ""!)

// then, paste this line:

kengruven

import Foundation

// inspired by <http://nshipster.com/nsregularexpression/>
extension String {
    var nsrange: NSRange {
        NSRange(location: 0, length: utf16.count)
    }

    func substring(with range: NSRange) -> String {
        (self as NSString).substring(with: range)

kengruven

import math

# "In a study of nearly half a million volunteers in China, those who
# ate chilies just a couple times a week had a 10 percent lower risk
# of death."
# http://www.scientificamerican.com/podcast/episode/spicy-food-linked-to-lower-risk-of-death/

# "Ooh, this is exciting. So what does a 10% lower risk of death mean,
# to me, in the real world?"