feat: add Partition for slice

slice/slice.go

@@ -1192,10 +1192,40 @@ func KeyBy[T any, U comparable](slice []T, iteratee func(item T) U) map[U]T {
 
 // Join the slice item with specify separator.
 // Play: https://go.dev/play/p/huKzqwNDD7V
-func Join[T any](s []T, separator string) string {
+func Join[T any](slice []T, separator string) string {
-	str := Map(s, func(_ int, item T) string {
+	str := Map(slice, func(_ int, item T) string {
 		return fmt.Sprint(item)
 	})
 
 	return strings.Join(str, separator)
 }
+
+// Partition all slice elements with the evaluation of the given predicate functions.
+// todo
+func Partition[T any](slice []T, predicates ...func(item T) bool) [][]T {
+	l := len(predicates)
+
+	result := make([][]T, l+1)
+
+	for _, item := range slice {
+		processed := false
+
+		for i, f := range predicates {
+			if f == nil {
+				panic("predicate function must not be nill")
+			}
+
+			if f(item) {
+				result[i] = append(result[i], item)
+				processed = true
+				break
+			}
+		}
+
+		if !processed {
+			result[l] = append(result[l], item)
+		}
+	}
+
+	return result
+}

slice/slice_example_test.go

@@ -1046,3 +1046,20 @@ func ExampleJoin() {
 	// 1,2,3,4,5
 	// 1-2-3-4-5
 }
+
+func ExamplePartition() {
+	nums := []int{1, 2, 3, 4, 5}
+
+	result1 := Partition(nums)
+	result2 := Partition(nums, func(n int) bool { return n%2 == 0 })
+	result3 := Partition(nums, func(n int) bool { return n == 1 || n == 2 }, func(n int) bool { return n == 2 || n == 3 || n == 4 })
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [[1 2 3 4 5]]
+	// [[2 4] [1 3 5]]
+	// [[1 2] [3 4] [5]]
+}

slice/slice_test.go

@@ -1175,3 +1175,13 @@ func TestJoin(t *testing.T) {
 	assert.Equal("1,2,3,4,5", result1)
 	assert.Equal("1-2-3-4-5", result2)
 }
+
+func TestPartition(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestPartition")
+
+	assert.Equal([][]int{{1, 2, 3, 4, 5}}, Partition([]int{1, 2, 3, 4, 5}))
+	assert.Equal([][]int{{2, 4}, {1, 3, 5}}, Partition([]int{1, 2, 3, 4, 5}, func(n int) bool { return n%2 == 0 }))
+	assert.Equal([][]int{{1, 2}, {3, 4}, {5}}, Partition([]int{1, 2, 3, 4, 5}, func(n int) bool { return n == 1 || n == 2 }, func(n int) bool { return n == 2 || n == 3 || n == 4 }))
+}