golang 柯里化（Currying）

使用场景：参数在语义上属于不同组，Go 语法无法在单次调用中声明多组可变参数，通过柯里化可以实现分步接收参数。
有的参数是在不同时间段产生，使用Currying可以让函数记住（缓存）参数，避免应用代码去手工管理缓存的参数。

demo代码：

package mainimport "fmt"// 2层柯里化函数：先接收arg，再接收otherArgs
func first(args ...int) func(args ...string) {return func(otherArgs ...string) {fmt.Println("Ints:", args)fmt.Println("Strings:", otherArgs)}
}// 三层柯里化函数：先接收int，再接收string，最后接收bool
func tripleCurry(a ...int) func(b ...string) func(c ...bool) {return func(b ...string) func(c ...bool) {return func(c ...bool) {fmt.Printf("Ints: %v\nStrings: %v\nBools: %v\n", a, b, c)}}
}// 四层柯里化函数：先接收int，再接收string，然后bool，最后[]byte
func tripleCurry4(a ...int) func(b ...string) func(c ...bool) func(d ...[]byte) {return func(b ...string) func(c ...bool) func(d ...[]byte) {return func(c ...bool) func(d ...[]byte) {return func(d ...[]byte) {fmt.Printf("Ints: %v\nStrings: %v\nBools: %v\nBytes: %v\n", a, b, c, d)}}}
}// 五层柯里化函数：先接收int，再接收string，然后bool，然后[]byte，最后float64
func tripleCurry5(a ...int) func(b ...string) func(c ...bool) func(d ...[]byte) func(e float64) {return func(b ...string) func(c ...bool) func(d ...[]byte) func(e float64) {return func(c ...bool) func(d ...[]byte) func(e float64) {return func(d ...[]byte) func(e float64) {return func(e float64) {fmt.Printf("Ints: %v\nStrings: %v\nBools: %v\nBytes: %v\n%v\n", a, b, c, d, e)}}}}
}func main() {fmt.Println("2层Currying")first(100, 200)("a", "b")fmt.Println()fmt.Println("3层Currying")tripleCurry(1, 2)("hello", "world")(true, false)fmt.Println()fmt.Println("4层Currying")tripleCurry4(1, 2)("hello", "world")(true, false)([]byte{0x01, 0x02})fmt.Println()fmt.Println("5层Currying")tripleCurry5(1, 2)("hello", "world")(true, false)([]byte{0x01, 0x02})(99.123)fmt.Println()// 分步调用示例/*step1 := tripleCurry4(10, 20)step2 := step1("foo", "bar")step3 := step2(true, false)step3([]byte{0x03, 0x04})*/
}

测试：

root@iZwz99zhkxxl5h6ecbm2xwZ:~/work/go# go mod init tt
go: /root/work/go/go.mod already exists
root@iZwz99zhkxxl5h6ecbm2xwZ:~/work/go# go mod tidy
root@iZwz99zhkxxl5h6ecbm2xwZ:~/work/go# 
root@iZwz99zhkxxl5h6ecbm2xwZ:~/work/go# ./tt 
2层Currying
Ints: [100 200]
Strings: [a b]3层Currying
Ints: [1 2]
Strings: [hello world]
Bools: [true false]4层Currying
Ints: [1 2]
Strings: [hello world]
Bools: [true false]
Bytes: [[1 2]]5层Currying
Ints: [1 2]
Strings: [hello world]
Bools: [true false]
Bytes: [[1 2]]
99.123root@iZwz99zhkxxl5h6ecbm2xwZ:~/work/go#