 }
 
 
-/// 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.

//  Copyright (c) 2014 Rob Rix. All rights reserved.

/// A singly-linked lazy list.
enum List<Element>: NilLiteralConvertible {
	// MARK: Constructors

	/// Nil case.

	}


	// MARK: Printable

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


	// MARK: Cases

	case Cons(Element, Box<List>)
