scala（2）借贷模式

[code]def withInt(x: Int, f :Int => Int): Unit = {
  println(f(x))
}

def add(x: Int) = { x+2 }
withInt(10, add)

[code]import scala.reflect.io.File
import java.util.Scanner

# 这里传入一个Scanner函数， 隐式参数Scanner，返回值为空。
def withScanner(f: File, op: Scanner => Unit) = {
    val scanner = new Scanner(f.bufferedReader)
    try {
        op(scanner)
    } finally {
        scanner.close()
    }
}

withScanner(File("/proc/self/stat"),
    scanner => println("pid is " + scanner.next()))