 	}
 
 
+	// MARK: Printable
+
+	var description: String {
+		let joined = join(" ", map(self) { "\($0)" })
+		return "(\(joined))"
+	}
+
+
 	// MARK: Cases
 
 	case Cons(Element, Box<List>)

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

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

	/// Nil case.

}


infix operator ++ { associativity right precedence 145 }

/// Concatenation of lists.
