Becca Royal-Gordon beccadax

Introducing `with` to the Standard Library

This proposal introduces a with function to the standard library. This function

This proposal enhances optional binding with a new, tuple-based syntax for

	extension String {
	func split(separator:String) -> [String] {
	return self.componentsSeparatedByString(separator)
	}
	}

	extension Array {
	func unpack() -> (T)? {
	return count == 1 ? (self[0]) : nil
	}

	public struct Distance :NumericType {
	public var value :Double
	public init(_ value: Double) {
	self.value = value
	}
	}

	extension Distance :IntegerLiteralConvertible {
	public init(integerLiteral: IntegerLiteralType) {
	self.init(Double(integerLiteral))

	// Evaluates the given closure when two `Optional` instances are not `nil`,
	// passing the unwrapped values as parameters. (Thanks, Mike Ash, Tim Vermeulen)
	// Following the example of IEEE754 with NAN, any comparison involving
	// .None is false
	//
	// See also: http://stackoverflow.com/questions/1565164/what-is-the-rationale-for-all-comparisons-returning-false-for-ieee754-nan-values

	/// Returns nil if either parameter is nil, or a tuple of the parameters
	/// otherwise.
	func all<T, U>(_ first: T?, _ second: U?) -> (T, U)? {

	print("""
	<?xml version="1.0"?>
	<catalog>
	\(bookTuples.map(xmlForBookTuple).joined(separator: "")
	)</catalog>
	""")

	typealias ChapterTuple = (heading: String)
	typealias BookTuple = (id: String, author: String, title: String, genre: String, price: String, chapters: [ChapterTuple])