// Apple Swift version 5.0.1 (swiftlang-1001.0.82.4 clang-1001.0.46.5)
// Target: x86_64-apple-darwin18.6.0

// Chapter: The Basics

// Constant declaration without immediate value assignment is legal.
let a: Int
a = 0

// Distinct integer types are comparable.
let b: UInt = 0
let c = a == b

// Typealiased values can be stored within an typealiased type's container.
typealias Boolean = Bool

let d: Boolean = false
let e = [c, d] // type: [Bool]
let f = [d, c] // type: [Boolean]

// Chapter: Basic Operators

// Nil-coalescing operator in-depth.
let g: String? = nil
let h: String? = nil
let i = g ?? h  // type: String?
let j = g ?? "" // type: String

// Unary logical operators work in constant declaration and assignment.
let k = !true

// Chapter: Collection Types

// Use tuple's member(s) as variable(s) in iteration of a Dictionary.
let l = [true: 1, false: 0]
for (_, var lv) in l {
    lv += 1
}

// Chapter: Control Flow

let m = stride(from: 0, to: 1, by: 1)       // type: StrideTo<Int>
let n = stride(from: 0, through: 1, by: 1)  // type: StrideThrough<Int>

// Chapter: Functions

// "Although it's possible for multiple parameters to have the same argument label, ..."
func o(p q: Bool, p r: Bool) -> Bool {
    return !q || r
}
let s = o(p: true, p: false)

// Optional function types.
let t: ((Bool, Bool) -> Bool)? = o
let u = t!(false, false)

// Chapter: Enumeration

// Boolean raw values are not allowed because it does not conform to RawRepresentable
// enum A: Bool {}