Graph.swift

Graph.swift

//
//  Graph.swift
//  CoreMesh
//
//  Created by Akio Yasui on 10/24/15.
//  Copyright © 2015 Akio Yasui. All rights reserved.
//

import Foundation

func ==(lhs: Node, rhs: Node) -> Bool {
	return lhs.hashValue == rhs.hashValue
}

func ==(lhs: Edge, rhs: Edge) -> Bool {
	return lhs.hashValue == rhs.hashValue
}

struct Graph {
	var nodes: Set<Node>
	var edges: Set<Edge>

	init(nodes: Set<Node> = Set(), edges: Set<Edge> = Set()) {
		self.nodes = nodes
		self.edges = edges
	}
}

struct Node: Equatable, Hashable, CustomStringConvertible {
	let UUID: NSUUID
	let label: String

	var hashValue: Int {
		let vs = UUID.integerValues
		return Int(Int32((vs.0 ^ vs.1) >> 33))
	}

	var description: String {
		return label
	}

	var debugDescription: String {
		return label
	}

	init(UUID: NSUUID, label: String) {
		self.UUID = UUID
		self.label = label
	}
}

struct Edge: Equatable, Hashable, CustomStringConvertible {
	let source: Node
	let target: Node

	var UUID: NSUUID {
		return NSUUID()
	}

	var hashValue: Int {
		return Int(UUID.integerValues.0 >> 33)
	}

	var description: String {
		return "\(source) <-(\(UUID.UUIDString))-> \(target)"
	}

	init(source: Node, target: Node) {
		self.source = source
		self.target = target
	}
}

extension NSUUID {
	var integerValues: (UInt64, UInt64) {
		var bytes = [UInt8](count: 16, repeatedValue: 0)
		self.getUUIDBytes(&bytes)
		let headData = NSData(bytes: Array(bytes[0 ..< 8]), length: sizeof(UInt8) * 8)
		var headValue = UInt64()
		headData.getBytes(&headValue, length: sizeof(UInt64))
		let tailData = NSData(bytes: Array(bytes[8 ..< 16]), length: sizeof(UInt8) * 8)
		var tailValue = UInt64()
		tailData.getBytes(&tailValue, length: sizeof(UInt64))
		return (headValue, tailValue)
	}
}