Swift URL Router

URLRouter.swift

class URLRouter {
    let placeholders: [String: String]
    init(placeholders: [String: String] = [:]) {
        self.placeholders = placeholders
    }
    
    typealias ActionHandler = ((NSURL)->())
    func register(path: String, handler: ActionHandler) -> Self {
        let pathWithoutRoot = path.hasPrefix("/") ? path.substringFromIndex(path.startIndex.advancedBy(1)) : path
        var node = root
        for pattern in pathWithoutRoot.componentsSeparatedByString("/").map({ placeholders[$0] ?? $0 }) {
            if pattern.isEmpty { break }
            if let child = node.childlen.filter({ $0.pattern == pattern }).first {
                node = child
            } else {
                let child = Node(pattern: pattern)
                node.childlen.append(child)
                node = child
            }
        }
        if node.handler == nil {
            node.handler = handler
        }
        
        return self
    }
    
    func handleURL(URL: NSURL) -> Bool {
        guard let components = URL.pathComponents else { return false }
        var node: Node? = nil
        for component in components {
            node = node == nil ? root : node?.childlen.filter({ $0.matches(component) }).first
            if node == nil { break }
        }
        node?.handler?(URL)
        return node?.handler != nil
    }
    
    private class Node {
        let pattern: String
        var childlen: [Node] = []
        var handler: ActionHandler? = nil
        init(pattern: String) {
            self.pattern = pattern
        }
        func matches(string: String) -> Bool {
            return string.rangeOfString(pattern, options:.RegularExpressionSearch) == (string.startIndex ..< string.endIndex)
        }
    }
    private var root: Node = Node(pattern: "/")
}