feat:线下课：函数柯里化

src/main/scala/chapter2/demo5/DemoCurrying.scala

@@ -0,0 +1,62 @@
+package chapter2.demo5
+
+object DemoCurrying {
+  def main(args: Array[String]): Unit = {
+
+    def add(x: Int, y: Int): Int = x + y
+
+    println(add(2, 3))
+
+    def addTaowa(x: Int): Int => Int = {
+      def add(y: Int): Int = x + y
+
+      add
+    }
+
+    println(addTaowa(2)(3))
+
+    def addTaowa2(x: Int): Int => Int = {
+      (y: Int) => x + y
+    }
+
+    println(addTaowa2(2)(3))
+    //  def add(x: Int, y: Int): Int = x + y
+    def addCurrying(x: Int)(y: Int): Int = {
+      x + y
+    }
+
+
+    val addLambda = (x:Int,y:Int) => x+y
+    // 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
+    val curriedAdd = addLambda.curried
+    addLambda(1,2)
+    curriedAdd(1)(2)
+
+    println(addCurrying(2)(3))
+    val add2 = addCurrying(2) _
+
+    add2(3)
+    add2(4)
+
+    // 柯里化的使用场景
+    // 柯里化可以部分记住参数的固定值
+    // debug info warn error
+    def log(level: String)(message: String): Unit = {
+      println(s"[$level] - $message")
+    }
+    log("info")("这是一条info级别的日志")
+    log("warn")("这是一条warn级别的日志")
+    log("error")("这是一条error级别的日志")
+
+    val infoLog = log("info") _
+    val warnLog = log("warn") _
+    val errorLog = log("error") _
+
+    // 闭包
+    infoLog("普通日志")
+    warnLog("告警日志")
+    errorLog("错误日志")
+
+
+  }
+}