 }
 
 
-operator infix ++ { associativity right precedence 145 }
+infix operator ++ { associativity right precedence 145 }
 
 /// Concatenation of lists.
 func ++ <Element> (left: List<Element>, right: List<Element>) -> List<Element> {

	}
	
	/// N-ary list from a sequence.
	init<S : Sequence where S.GeneratorType.Element == Element>(elements: S) {
		self = List(generator: elements.generate())
	}
}


/// Lists conform to Sequence.
extension List : Sequence {
	func generate() -> GeneratorOf<Element> {
		var list = self
		return GeneratorOf {

	}
	
	/// N-ary list from a generator.
	init<G: GeneratorType where G.Element == Element>(var generator: G) {
		if let next: Element = generator.next() {
			self = .Node(next, [ List(generator: generator) ])
		} else {
