Merge pull request #52 from tsingbx/lambda

modify lambda expression

205-Lambda-expressions/lambda-expressions-1.gop

@@ -0,0 +1,18 @@
+// Lambda expressions are used when we want to define a function inline without giving it any name.
+
+// The following example shows the lambda expression of go+ style, which is more compact and easy to understand.
+
+func transform(a []float64, f func(float64) float64) []float64 {
+	return [f(x) for x <- a]
+}
+
+y := transform([1, 2, 3], x => x * x)
+println y // [1 4 9]
+
+z := transform([-3, 1, -5], x => {
+	if x < 0 {
+		return -x
+	}
+	return x
+})
+println z // [3 1 5]

205-Lambda-expressions/lambda-expressions-2.gop

@@ -0,0 +1,11 @@
+
+// If we want a lambda to be defined without being executed, we only omit its identifier. For example:
+
+func returnLambda() func(string) {
+	return func(msg string) {
+		println msg
+	}
+}
+
+consoleLog := returnLambda()
+consoleLog "Hello"

205-Lambda-expressions/lambda-expressions-3.gop

@@ -0,0 +1,6 @@
+
+// If we want the lambda to be defined and executed, we omit its identifier and add an argument list in parentheses after the body’s closing curly brace. For example: 
+
+func(msg string) {
+	println msg
+}("Hello")