object extendBuiltins extends Application {
def fact(n: Int): BigInt =
if (n == 0) 1 else fact(n-1) * n
class Factorizer(n: Int) {
def ! = fact(n)
}
implicit def int2fact(n: Int) = new Factorizer(n)println("10! = " + (10!))
}
这是官方网站原来的代码，我改了一下，变成下面的样子：
object extendBuiltins extends Application {
def fact(n: Int): BigInt =
if (n == 0) 1 else fact(n-1) * n
class Factorizer(n: Int) {
def ! = fact(n)
}
class Factorizer2(n: Int) {
def a = fact(n)
}
implicit def a(n: Int) = new Factorizer(n)
implicit def b(n: Int) = new Factorizer2(n)println("10! = " + (10!))
println("10! = " + (10.a))
}
我的问题是：为什么“!”，就可以直接挂在10后面，而“a”，就一定要加一个“.”在前面呢？
问题补充
再看一个：
object implicits extends Application {
implicit def arrayWrapperA =
new {
def !(p: (A, A) => Boolean) = {
util.Sorting.stableSort(x, p); x
}
}
val x = Array(2, 3, 1, 4)
println("x = "+ x.!((x: Int, y: Int) => x < y))
}
这里面的“!”，前面不加“.”，也会报错。。。
