63 lines
1.3 KiB
Scala
63 lines
1.3 KiB
Scala
package chapter2.demo5
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object DemoCurrying {
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def main(args: Array[String]): Unit = {
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def add(x: Int, y: Int): Int = x + y
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println(add(2, 3))
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def addTaowa(x: Int): Int => Int = {
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def add(y: Int): Int = x + y
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add
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}
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println(addTaowa(2)(3))
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def addTaowa2(x: Int): Int => Int = {
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(y: Int) => x + y
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}
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println(addTaowa2(2)(3))
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// def add(x: Int, y: Int): Int = x + y
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def addCurrying(x: Int)(y: Int): Int = {
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x + y
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}
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val addLambda = (x:Int,y:Int) => x+y
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// add是普通函数，可以通过scala自带的curried方法转成一个柯里化函数
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val curriedAdd = addLambda.curried
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addLambda(1,2)
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curriedAdd(1)(2)
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println(addCurrying(2)(3))
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val add2 = addCurrying(2) _
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add2(3)
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add2(4)
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// 柯里化的使用场景
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// 柯里化可以部分记住参数的固定值
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// debug info warn error
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def log(level: String)(message: String): Unit = {
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println(s"[$level] - $message")
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}
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log("info")("这是一条info级别的日志")
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log("warn")("这是一条warn级别的日志")
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log("error")("这是一条error级别的日志")
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val infoLog = log("info") _
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val warnLog = log("warn") _
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val errorLog = log("error") _
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// 闭包
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infoLog("普通日志")
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warnLog("告警日志")
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errorLog("错误日志")
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}
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}
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