Slice: padding (#201)

* LeftPadding adds padding to the left begin of a slice.
* RightPadding adds padding to the right end of a slice.

docs/api/packages/slice.md

@@ -95,6 +95,8 @@ import (
 -   [Partition](#Partition)
 -   [SetToDefaultIf](#SetToDefaultIf)
 -   [Break](#Break)
+-   [RightPadding](#RightPadding)
+-   [LeftPadding](#LeftPadding)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -2607,13 +2609,13 @@ func main() {
 
 <p>根据判断函数将切片分成两部分。它开始附加到与函数匹配的第一个元素之后的第二个切片。第一个匹配之后的所有元素都包含在第二个切片中，无论它们是否与函数匹配。</p>
 
-<b>示例:</b>
+<b>函数签名:</b>
 
 ```go
 func Break[T any](values []T, predicate func(T) bool) ([]T, []T)
 ```
 
-<b>Example:</b>
+<b>示例:</b>
 
 ```go
 import (
@@ -2634,4 +2636,58 @@ func main() {
     // [1]
     // [2 3 4 5]
 }
+```
+
+<span id="RightPadding">RightPadding</span>
+
+<p>TBD</p>
+
+<b>函数签名:</b>
+
+```go
+func RightPadding[T any](slice []T, paddingValue T, paddingLength int) []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+  	nums := []int{1, 2, 3, 4, 5}
+	padded := slice.RightPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [1 2 3 4 5 0 0 0]
+}
+```
+
+<span id="LeftPadding">LeftPadding</span>
+
+<p>TBD</p>
+
+<b>函数签名:</b>
+
+```go
+func LeftPadding[T any](slice []T, paddingValue T, paddingLength int) []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+  	nums := []int{1, 2, 3, 4, 5}
+	padded := slice.LeftPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [0 0 0 1 2 3 4 5]
+}
 ```

docs/en/api/packages/slice.md

@@ -95,6 +95,8 @@ import (
 -   [Partition](#Partition)
 -   [SetToDefaultIf](#SetToDefaultIf)
 -   [Break](#Break)
+-   [RightPadding](#RightPadding)
+-   [LeftPadding](#LeftPadding)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -2631,4 +2633,58 @@ func main() {
     // [1]
     // [2 3 4 5]
 }
+```
+
+<span id="c">RightPadding</span>
+
+<p>RightPadding adds padding to the right end of a slice.</p>
+
+<b>Signature:</b>
+
+```go
+func RightPadding[T any](slice []T, paddingValue T, paddingLength int) []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+  	nums := []int{1, 2, 3, 4, 5}
+	padded := RightPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [1 2 3 4 5 0 0 0]
+}
+```
+
+<span id="LeftPadding">LeftPadding</span>
+
+<p>LeftPadding adds padding to the left begin of a slice.</p>
+
+<b>Signature:</b>
+
+```go
+func LeftPadding[T any](slice []T, paddingValue T, paddingLength int) []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+  	nums := []int{1, 2, 3, 4, 5}
+	padded := LeftPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [0 0 0 1 2 3 4 5]
+}
 ```

slice/slice.go

@@ -1273,3 +1273,35 @@ func Random[T any](slice []T) (val T, idx int) {
 	idx = random.RandInt(0, len(slice))
 	return slice[idx], idx
 }
+
+// RightPadding adds padding to the right end of a slice.
+// Play: Todo
+func RightPadding[T any](slice []T, paddingValue T, paddingLength int) []T {
+	if paddingLength == 0 {
+		return slice
+	}
+	for i := 0; i < paddingLength; i++ {
+		slice = append(slice, paddingValue)
+	}
+	return slice
+}
+
+// LeftPadding adds padding to the left begin of a slice.
+// Play: Todo
+func LeftPadding[T any](slice []T, paddingValue T, paddingLength int) []T {
+	if paddingLength == 0 {
+		return slice
+	}
+
+	paddedSlice := make([]T, len(slice)+paddingLength)
+	i := 0
+	for ; i < paddingLength; i++ {
+		paddedSlice[i] = paddingValue
+	}
+	for j := 0; j < len(slice); j++ {
+		paddedSlice[i] = slice[j]
+		i++
+	}
+
+	return paddedSlice
+}

slice/slice_example_test.go

@@ -1125,3 +1125,19 @@ func ExampleBreak() {
 	// [1]
 	// [2 3 4 5]
 }
+
+func ExampleRightPadding() {
+	nums := []int{1, 2, 3, 4, 5}
+	padded := RightPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [1 2 3 4 5 0 0 0]
+}
+
+func ExampleLeftPadding() {
+	nums := []int{1, 2, 3, 4, 5}
+	padded := LeftPadding(nums, 0, 3)
+	fmt.Println(padded)
+	// Output:
+	// [0 0 0 1 2 3 4 5]
+}

slice/slice_test.go

@@ -1396,3 +1396,15 @@ func TestBreak(t *testing.T) {
 	assert.Equal([]int{1, 3, 5, 7, 9}, resultAllOdd)
 	assert.Equal([]int{}, emptyResult)
 }
+
+func TestRightPaddingAndLeftPadding(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "RightPaddingAndLeftPadding")
+
+	// Test with integers
+	nums := []int{1, 2, 3, 4, 5}
+
+	padded := LeftPadding(RightPadding(nums, 0, 3), 0, 3)
+	assert.Equal([]int{0, 0, 0, 1, 2, 3, 4, 5, 0, 0, 0}, padded)
+}