Linked list

gistfile1.txt

public final class LinkedList<T> {
    public final class Node<T> {
        public private(set) var value: T
        public var next: Node?

        public init(value: T) {
            self.value = value
        }
    }

    public init(nodes: [T]) {
        let listNodes = nodes.map(Node.init(value:))
        var node = listNodes.first
        head = node
        listNodes.dropFirst().forEach { next in
            node?.next = next
            node = next
        }
    }

    private var head: Node<T>?

    public var isEmpty: Bool {
        return head == nil
    }

    public var first: Node<T>? {
        return head
    }
}

extension LinkedList.Node: CustomStringConvertible {
    public var description: String {
        return "Node \(value)"
    }
}

extension LinkedList: CustomStringConvertible {
    public var description: String {
        guard var node = head else  { return "Empty list" }
        var result = "\(node.value)"
        while let next = node.next {
            node = next
            result.append(", \(node.value)")
        }
        result.insert("[", at: result.startIndex)
        result.insert("]", at: result.endIndex)
        return result
    }
}