cycle.swift

/// All the ways to zip.
///
/// The Swift standard library doesn't seem to have a way to cycle an element so
/// that it can be paired with something else in a zip. These are the ways I've
/// found to achieve the same effect. The last one, `.map({($0, z)})` might be
/// the most idiomatic Swift (and is also the shortest one to express in Swift).

let xs = [1, 2, 3]
let y = 1...10

for (x, y) in zip(xs, repeatElement(y, count: .max)) {
    print(x, y)
}

for (x, y) in zip(xs, sequence(first: y) { $0 }) {
    print(x, y)
}

for (x, y) in xs.map({ ($0, y) }) {
    print(x, y)
}