【32】kotlin 科理化（Currying） 函数调用链

理解Currying 概念

简单说就是多元函数变换成一元函数调用链

了解Curring的实现方法

 

实例1 

package com.yzdzy.kotlin.chapter5.currying

fun hello(x: String, y: Int, z: Double): Boolean {
    return true
}

fun currideHello(x: String): (y: Int) -> (z: Double) -> Boolean {
    
}

实例2

package com.yzdzy.kotlin.chapter5.currying

import java.io.OutputStream

fun log(tag: String, target: OutputStream, message: Any?) {
    target.write("[$tag] $message\n".toByteArray())

}

fun log(tag: String) = fun(target: OutputStream) = fun(message: Any?) = target.write("[$tag] $message\n".toByteArray())

// fun <P1, P2, P3, R> Function3<P1, P2, P3, R>.curried() =
//    fun(p1: P1) = fun(p2: P2) = fun(p3: P3) = this(p1, p2, p3)

fun main(args: Array<String>) {
    log("benny", System.out, "Hello world")
    log("benny")(System.out)("Hello world again")

}

实例3 

package com.yzdzy.kotlin.chapter5.currying

import java.io.OutputStream

fun log(tag: String, target: OutputStream, message: Any?) {
    target.write("[$tag] $message\n".toByteArray())

}

//fun log(tag: String) = fun(target: OutputStream) = fun(message: Any?) = target.write("[$tag] $message\n".toByteArray())

 fun <P1, P2, P3, R> Function3<P1, P2, P3, R>.curried() =
    fun(p1: P1) = fun(p2: P2) = fun(p3: P3) = this(p1, p2, p3)

fun main(args: Array<String>) {
    log("benny", System.out, "Hello world")
    ::log.curried()("benny")(System.out)("Hello world again")

}