feat: add Pipeline function

function/function.go

@@ -113,3 +113,15 @@ func Schedule(d time.Duration, fn any, args ...any) chan bool {
 
 	return quit
 }
+
+// Pipeline takes a list of functions and returns a function whose param will be passed into
+// the functions one by one.
+func Pipeline[T any](funcs ...func(T) T) func(T) T {
+	return func(arg T) (result T) {
+		result = arg
+		for _, fn := range funcs {
+			result = fn(result)
+		}
+		return
+	}
+}

function/function_test.go

@@ -134,3 +134,21 @@ func TestSchedule(t *testing.T) {
 	// expected := []string{"*", "*", "*", "*", "*"}
 	// assert.Equal(expected, res)
 }
+
+func TestPipeline(t *testing.T) {
+	assert := internal.NewAssert(t, "TestPipeline")
+
+	addOne := func(x int) int {
+		return x + 1
+	}
+	double := func(x int) int {
+		return 2 * x
+	}
+	square := func(x int) int {
+		return x * x
+	}
+
+	f := Pipeline(addOne, double, square)
+
+	assert.Equal(36, f(2))
+}

function/watcher_test.go

@@ -1,6 +1,7 @@
 package function
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/duke-git/lancet/v2/internal"
@@ -34,4 +35,5 @@ func longRunningTask() {
 	for i := 0; i < 10000000; i++ {
 		slice = append(slice, int64(i))
 	}
+	fmt.Println(slice)
 }