scala一些高级类型

package com.ming.test

import scala.collection.mutable.ArrayBuffer
import scala.io.Source
import java.awt.image.BufferedImage
import javax.imageio.ImageIO
import java.io.File

/**
* 高级类型
*/
//单例类型，链式调用
class Document{
def setTitle(title:String)={this}
def setAuthor(author:String)={this}
}

class Book extends Document{
def addBook(name:String):this.type={this}
}

//类型投影
class NetWork{
class Member(val name:String){
val contacts=new ArrayBuffer[Member]
}
private val members=new ArrayBuffer[Member]
def join(name:String)={
val m=new Member(name)
members+=m
m
}
}

//定义Person类，两个泛型参数，分别是S，T,因此
//它是可以用中置表达式进行变量定义的
case class Person[S,T](val name:S,val age:T)
//中置类型-中置类型是代表带有两个参数的类型
class ZhongziType{
//下面的代码是一种中置表达方法，相当于
//val p:Person[String,Int]
val p:String Person Int= Person("摇摆少年梦",18)
}

//抽象类型--类或特质可以定义一个在子类中被具体化的抽象类型
trait Reader{
type Contents
def read(fileName : String):Contents
}

trait Reade1r[T]{
def read(fileName : String):T
}

//类型Contents是抽象的。具体的子类需要指定这个类型
class StringReader extends Reader{
type Contents=String
def read(fileName : String)=Source.fromFile(fileName,"UTF-8").mkString
}

class ImageReader extends Reader{
type Contents=BufferedImage
def read(fileName :String)=ImageIO.read(new File(fileName))
}

//

object SeniorTypeTest {

def main(args: Array[String]): Unit = {
var d=new Book
var s=d.setAuthor("a").setTitle("hello");
println(s)
var b=new Book
b.addBook("<<helloworld>>").setAuthor("mingge").setTitle("hello")
println(b)
}
}