 //  Copyright (c) 2014 Rob Rix. All rights reserved.
 
 /// A singly-linked lazy list.
-enum List<Element>: NilLiteralConvertible {
+enum List<Element>: NilLiteralConvertible, Printable {
 	// MARK: Constructors
 
 	/// Nil case.

}


/// Lists conform to Printable.
extension List: Printable {
	var description: String {
		let joined = join(" ", map(self) { "\($0)" })
		return "(\(joined))"
	}
}


infix operator ++ { associativity right precedence 145 }

/// Concatenation of lists.

	}


	// MARK: Printable

	var description: String {
		let joined = join(" ", map(self) { "\($0)" })
		return "(\(joined))"
	}


	// MARK: Cases

	case Cons(Element, Box<List>)
