refactor: use constraints from golang.org/x/exp/constraints

concurrency/channel.go

@@ -158,7 +158,7 @@ func (c *Channel) Bridge(ctx context.Context, chanStream <-chan <-chan any) <-ch
 			var stream <-chan any
 			select {
 			case maybeStream, ok := <-chanStream:
-				if ok == false {
+				if !ok {
 					return
 				}
 				stream = maybeStream

convertor/convertor.go

@@ -97,38 +97,41 @@ func ToString(value any) string {
 		return ""
 	}
 
-	switch value.(type) {
+	switch val := value.(type) {
 	case float32:
-		return strconv.FormatFloat(float64(value.(float32)), 'f', -1, 32)
+		return strconv.FormatFloat(float64(val), 'f', -1, 32)
 	case float64:
-		return strconv.FormatFloat(value.(float64), 'f', -1, 64)
+		return strconv.FormatFloat(val, 'f', -1, 64)
 	case int:
-		return strconv.FormatInt(int64(value.(int)), 10)
+		return strconv.FormatInt(int64(val), 10)
 	case int8:
-		return strconv.FormatInt(int64(value.(int8)), 10)
+		return strconv.FormatInt(int64(val), 10)
 	case int16:
-		return strconv.FormatInt(int64(value.(int16)), 10)
+		return strconv.FormatInt(int64(val), 10)
 	case int32:
-		return strconv.FormatInt(int64(value.(int32)), 10)
+		return strconv.FormatInt(int64(val), 10)
 	case int64:
-		return strconv.FormatInt(value.(int64), 10)
+		return strconv.FormatInt(val, 10)
 	case uint:
-		return strconv.FormatUint(uint64(value.(uint)), 10)
+		return strconv.FormatUint(uint64(val), 10)
 	case uint8:
-		return strconv.FormatUint(uint64(value.(uint8)), 10)
+		return strconv.FormatUint(uint64(val), 10)
 	case uint16:
-		return strconv.FormatUint(uint64(value.(uint16)), 10)
+		return strconv.FormatUint(uint64(val), 10)
 	case uint32:
-		return strconv.FormatUint(uint64(value.(uint32)), 10)
+		return strconv.FormatUint(uint64(val), 10)
 	case uint64:
-		return strconv.FormatUint(value.(uint64), 10)
+		return strconv.FormatUint(val, 10)
 	case string:
-		return value.(string)
+		return val
 	case []byte:
-		return string(value.([]byte))
+		return string(val)
 	default:
-		newValue, _ := json.Marshal(value)
-		return string(newValue)
+		b, err := json.Marshal(val)
+		if err != nil {
+			return ""
+		}
+		return string(b)
 
 		// todo: maybe we should't supprt other type conversion
 		// v := reflect.ValueOf(value)

convertor/convertor_test.go

@@ -27,14 +27,9 @@ func TestToChannel(t *testing.T) {
 	assert := internal.NewAssert(t, "TestToChannel")
 
 	ch := ToChannel([]int{1, 2, 3})
-	val1, _ := <-ch
-	assert.Equal(1, val1)
-
-	val2, _ := <-ch
-	assert.Equal(2, val2)
-
-	val3, _ := <-ch
-	assert.Equal(3, val3)
+	assert.Equal(1, <-ch)
+	assert.Equal(2, <-ch)
+	assert.Equal(3, <-ch)
 
 	_, ok := <-ch
 	assert.Equal(false, ok)
@@ -254,6 +249,7 @@ func TestDecodeByte(t *testing.T) {
 
 	var obj string
 	byteData := []byte{6, 12, 0, 3, 97, 98, 99}
-	DecodeByte(byteData, &obj)
+	err := DecodeByte(byteData, &obj)
+	assert.IsNil(err)
 	assert.Equal("abc", obj)
 }

cryptor/rsa.go

@@ -33,7 +33,11 @@ func GenerateRsaKey(keySize int, priKeyFile, pubKeyFile string) error {
 	if err != nil {
 		panic(err)
 	}
-	pem.Encode(file, &block)
+	err = pem.Encode(file, &block)
+	if err != nil {
+		return err
+	}
+
 	file.Close()
 
 	// public key
@@ -49,12 +53,16 @@ func GenerateRsaKey(keySize int, priKeyFile, pubKeyFile string) error {
 		Bytes: derpText,
 	}
 
-	//file,err = os.Create("rsa_public.pem")
 	file, err = os.Create(pubKeyFile)
 	if err != nil {
 		return err
 	}
-	pem.Encode(file, &block)
+
+	err = pem.Encode(file, &block)
+	if err != nil {
+		return err
+	}
+
 	file.Close()
 
 	return nil
@@ -72,7 +80,11 @@ func RsaEncrypt(data []byte, pubKeyFileName string) []byte {
 	}
 	defer file.Close()
 	buf := make([]byte, fileInfo.Size())
-	file.Read(buf)
+
+	_, err = file.Read(buf)
+	if err != nil {
+		panic(err)
+	}
 
 	block, _ := pem.Decode(buf)
 
@@ -101,7 +113,11 @@ func RsaDecrypt(data []byte, privateKeyFileName string) []byte {
 	}
 	buf := make([]byte, fileInfo.Size())
 	defer file.Close()
-	file.Read(buf)
+
+	_, err = file.Read(buf)
+	if err != nil {
+		panic(err)
+	}
 
 	block, _ := pem.Decode(buf)
 

datastructure/heap/maxheap.go

@@ -146,9 +146,9 @@ func (h *MaxHeap[T]) PrintStructure() {
 	lastNum := powerTwo(level - 1)
 	lastLen := lastNum + (lastNum - 1)
 
-	heapTree := make([][]string, level, level)
+	heapTree := make([][]string, level)
 	for i := 0; i < level; i++ {
-		heapTree[i] = make([]string, lastLen, lastLen)
+		heapTree[i] = make([]string, lastLen)
 		for j := 0; j < lastLen; j++ {
 			heapTree[i][j] = ""
 		}
@@ -169,9 +169,9 @@ func (h *MaxHeap[T]) PrintStructure() {
 		for n := 0; n < lastLen; n++ {
 			val := heapTree[m][n]
 			if val == "" {
-				fmt.Printf(" ")
+				fmt.Print(" ")
 			} else {
-				fmt.Printf(val)
+				fmt.Print(val)
 			}
 		}
 		fmt.Println()

datastructure/heap/maxheap_test.go

@@ -30,8 +30,6 @@ func TestMaxHeap_BuildMaxHeap(t *testing.T) {
 	assert.Equal(expected, heap.data)
 
 	assert.Equal(12, heap.Size())
-
-	heap.PrintStructure()
 }
 
 func TestMaxHeap_Push(t *testing.T) {

datastructure/link/doublylink.go

@@ -1,13 +1,12 @@
 package datastructure
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/duke-git/lancet/v2/datastructure"
 )
 
-// DoublyLink is a linked list. Whose node has a generic Value, Pre pointer points to a previous node of the link, Next pointer points to a next node of the link.
+// DoublyLink is a linked list. Whose node has a generic Value, Pre pointer points to a previous node of the dl, Next pointer points to a next node of the dl.
 type DoublyLink[T any] struct {
 	Head   *datastructure.LinkNode[T]
 	length int
@@ -19,30 +18,30 @@ func NewDoublyLink[T any]() *DoublyLink[T] {
 }
 
 // InsertAtHead insert value into doubly linklist at head index
-func (link *DoublyLink[T]) InsertAtHead(value T) {
+func (dl *DoublyLink[T]) InsertAtHead(value T) {
 	newNode := datastructure.NewLinkNode(value)
-	size := link.Size()
+	size := dl.Size()
 
 	if size == 0 {
-		link.Head = newNode
-		link.length++
+		dl.Head = newNode
+		dl.length++
 		return
 	}
 
-	newNode.Next = link.Head
+	newNode.Next = dl.Head
 	newNode.Pre = nil
 
-	link.Head.Pre = newNode
-	link.Head = newNode
+	dl.Head.Pre = newNode
+	dl.Head = newNode
 
-	link.length++
+	dl.length++
 }
 
 // InsertAtTail insert value into doubly linklist at tail index
-func (link *DoublyLink[T]) InsertAtTail(value T) {
-	current := link.Head
+func (dl *DoublyLink[T]) InsertAtTail(value T) {
+	current := dl.Head
 	if current == nil {
-		link.InsertAtHead(value)
+		dl.InsertAtHead(value)
 		return
 	}
 
@@ -55,28 +54,29 @@ func (link *DoublyLink[T]) InsertAtTail(value T) {
 	newNode.Pre = current
 	current.Next = newNode
 
-	link.length++
+	dl.length++
 }
 
 // InsertAt insert value into doubly linklist at index
-func (link *DoublyLink[T]) InsertAt(index int, value T) error {
-	size := link.length
+// param `index` should between [0, length], if index do not meet the conditions, do nothing
+func (dl *DoublyLink[T]) InsertAt(index int, value T) {
+	size := dl.length
 	if index < 0 || index > size {
-		return errors.New("param index should between 0 and the length of doubly link.")
+		return
 	}
 
 	if index == 0 {
-		link.InsertAtHead(value)
-		return nil
+		dl.InsertAtHead(value)
+		return
 	}
 
 	if index == size {
-		link.InsertAtTail(value)
-		return nil
+		dl.InsertAtTail(value)
+		return
 	}
 
 	i := 0
-	current := link.Head
+	current := dl.Head
 
 	for current != nil {
 		if i == index-1 {
@@ -85,38 +85,36 @@ func (link *DoublyLink[T]) InsertAt(index int, value T) error {
 			newNode.Pre = current
 
 			current.Next = newNode
-			link.length++
+			dl.length++
 
-			return nil
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("doubly link list no exist")
 }
 
 // DeleteAtHead delete value in doubly linklist at head index
-func (link *DoublyLink[T]) DeleteAtHead() error {
-	if link.Head == nil {
-		return errors.New("doubly link list no exist")
-	}
-	current := link.Head
-	link.Head = current.Next
-	link.Head.Pre = nil
-	link.length--
-
-	return nil
+func (dl *DoublyLink[T]) DeleteAtHead() {
+	if dl.Head == nil {
+		return
 	}
 
-// DeleteAtTail delete value in doubly linklist at tail index
-func (link *DoublyLink[T]) DeleteAtTail() error {
-	if link.Head == nil {
-		return errors.New("doubly link list no exist")
+	current := dl.Head
+	dl.Head = current.Next
+	dl.Head.Pre = nil
+	dl.length--
 }
-	current := link.Head
+
+// DeleteAtTail delete value in doubly linklist at tail
+func (dl *DoublyLink[T]) DeleteAtTail() {
+	if dl.Head == nil {
+		return
+	}
+
+	current := dl.Head
 	if current.Next == nil {
-		return link.DeleteAtHead()
+		dl.DeleteAtHead()
 	}
 
 	for current.Next.Next != nil {
@@ -124,45 +122,44 @@ func (link *DoublyLink[T]) DeleteAtTail() error {
 	}
 
 	current.Next = nil
-	link.length--
-	return nil
+	dl.length--
 }
 
 // DeleteAt delete value in doubly linklist at index
-func (link *DoublyLink[T]) DeleteAt(index int) error {
-	if link.Head == nil {
-		return errors.New("doubly link list no exist")
+// param `index` should be [0, len(DoublyLink)-1]
+func (dl *DoublyLink[T]) DeleteAt(index int) {
+	if dl.Head == nil {
+		return
 	}
-	current := link.Head
+
+	current := dl.Head
 	if current.Next == nil || index == 0 {
-		return link.DeleteAtHead()
+		dl.DeleteAtHead()
 	}
 
-	if index == link.length-1 {
-		return link.DeleteAtTail()
+	if index == dl.length-1 {
+		dl.DeleteAtTail()
 	}
 
-	if index < 0 || index > link.length-1 {
-		return errors.New("param index should between 0 and link size -1.")
+	if index < 0 || index > dl.length-1 {
+		return
 	}
 
 	i := 0
 	for current != nil {
 		if i == index-1 {
 			current.Next = current.Next.Next
-			link.length--
-			return nil
+			dl.length--
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("delete error")
 }
 
 // Reverse the linked list
-func (link *DoublyLink[T]) Reverse() {
-	current := link.Head
+func (dl *DoublyLink[T]) Reverse() {
+	current := dl.Head
 	var temp *datastructure.LinkNode[T]
 
 	for current != nil {
@@ -173,20 +170,20 @@ func (link *DoublyLink[T]) Reverse() {
 	}
 
 	if temp != nil {
-		link.Head = temp.Pre
+		dl.Head = temp.Pre
 	}
 }
 
 // GetMiddleNode return node at middle index of linked list
-func (link *DoublyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
-	if link.Head == nil {
+func (dl *DoublyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
+	if dl.Head == nil {
 		return nil
 	}
-	if link.Head.Next == nil {
-		return link.Head
+	if dl.Head.Next == nil {
+		return dl.Head
 	}
-	fast := link.Head
-	slow := link.Head
+	fast := dl.Head
+	slow := dl.Head
 
 	for fast != nil {
 		fast = fast.Next
@@ -202,14 +199,14 @@ func (link *DoublyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
 }
 
 // Size return the count of doubly linked list
-func (link *DoublyLink[T]) Size() int {
-	return link.length
+func (dl *DoublyLink[T]) Size() int {
+	return dl.length
 }
 
 // Values return slice of all doubly linklist node value
-func (link *DoublyLink[T]) Values() []T {
+func (dl *DoublyLink[T]) Values() []T {
 	result := []T{}
-	current := link.Head
+	current := dl.Head
 	for current != nil {
 		result = append(result, current.Value)
 		current = current.Next
@@ -218,8 +215,8 @@ func (link *DoublyLink[T]) Values() []T {
 }
 
 // Print all nodes info of a linked list
-func (link *DoublyLink[T]) Print() {
-	current := link.Head
+func (dl *DoublyLink[T]) Print() {
+	current := dl.Head
 	info := "[ "
 	for current != nil {
 		info += fmt.Sprintf("%+v, ", current)
@@ -229,13 +226,13 @@ func (link *DoublyLink[T]) Print() {
 	fmt.Println(info)
 }
 
-// IsEmpty checks if link is empty or not
-func (link *DoublyLink[T]) IsEmpty() bool {
-	return link.length == 0
+// IsEmpty checks if dl is empty or not
+func (dl *DoublyLink[T]) IsEmpty() bool {
+	return dl.length == 0
 }
 
 // Clear all nodes in doubly linklist
-func (link *DoublyLink[T]) Clear() {
-	link.Head = nil
-	link.length = 0
+func (dl *DoublyLink[T]) Clear() {
+	dl.Head = nil
+	dl.length = 0
 }

datastructure/link/doublylink_test.go

@@ -41,29 +41,24 @@ func TestDoublyLink_InsertAt(t *testing.T) {
 
 	link := NewDoublyLink[int]()
 
-	err := link.InsertAt(1, 1)
-	assert.IsNotNil(err)
+	link.InsertAt(1, 1) //do nothing
 
 	link.InsertAt(0, 1)
 	link.InsertAt(1, 2)
 	link.InsertAt(2, 4)
 	link.InsertAt(2, 3)
 
-	link.Print()
-
 	expected := []int{1, 2, 3, 4}
 	values := link.Values()
 
 	assert.Equal(expected, values)
-
 }
 
 func TestDoublyLink_DeleteAtHead(t *testing.T) {
 	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAtHead")
 
 	link := NewDoublyLink[int]()
-	err := link.DeleteAtHead()
-	assert.IsNotNil(err)
+	link.DeleteAtHead()
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -71,7 +66,6 @@ func TestDoublyLink_DeleteAtHead(t *testing.T) {
 	link.InsertAtTail(4)
 
 	link.DeleteAtHead()
-	link.Print()
 
 	expected := []int{2, 3, 4}
 	values := link.Values()
@@ -83,8 +77,7 @@ func TestDoublyLink_DeleteAtTail(t *testing.T) {
 	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAtTail")
 
 	link := NewDoublyLink[int]()
-	err := link.DeleteAtTail()
-	assert.IsNotNil(err)
+	link.DeleteAtTail()
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -92,7 +85,6 @@ func TestDoublyLink_DeleteAtTail(t *testing.T) {
 	link.InsertAtTail(4)
 
 	link.DeleteAtTail()
-	link.Print()
 
 	expected := []int{1, 2, 3}
 	values := link.Values()
@@ -104,8 +96,7 @@ func TestDoublyLink_DeleteAt(t *testing.T) {
 	assert := internal.NewAssert(t, "TestDoublyLink_DeleteAt")
 
 	link := NewDoublyLink[int]()
-	err := link.DeleteAt(0)
-	assert.IsNotNil(err)
+	link.DeleteAt(0)
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -113,11 +104,7 @@ func TestDoublyLink_DeleteAt(t *testing.T) {
 	link.InsertAtTail(4)
 	link.InsertAtTail(5)
 
-	err = link.DeleteAt(5)
-	assert.IsNotNil(err)
-
-	err = link.DeleteAt(0)
-	assert.IsNil(err)
+	link.DeleteAt(0)
 	assert.Equal([]int{2, 3, 4, 5}, link.Values())
 
 	link.DeleteAt(3)

datastructure/link/singlylink.go

@@ -1,14 +1,13 @@
 package datastructure
 
 import (
-	"errors"
 	"fmt"
 	"reflect"
 
 	"github.com/duke-git/lancet/v2/datastructure"
 )
 
-// SinglyLink is a linked list. Whose node has a Value generics and Next pointer points to a next node of the link.
+// SinglyLink is a linked list. Whose node has a Value generics and Next pointer points to a next node of the sl.
 type SinglyLink[T any] struct {
 	Head   *datastructure.LinkNode[T]
 	length int
@@ -20,18 +19,18 @@ func NewSinglyLink[T any]() *SinglyLink[T] {
 }
 
 // InsertAtHead insert value into singly linklist at head index
-func (link *SinglyLink[T]) InsertAtHead(value T) {
+func (sl *SinglyLink[T]) InsertAtHead(value T) {
 	newNode := datastructure.NewLinkNode(value)
-	newNode.Next = link.Head
-	link.Head = newNode
-	link.length++
+	newNode.Next = sl.Head
+	sl.Head = newNode
+	sl.length++
 }
 
 // InsertAtTail insert value into singly linklist at tail index
-func (link *SinglyLink[T]) InsertAtTail(value T) {
-	current := link.Head
+func (sl *SinglyLink[T]) InsertAtTail(value T) {
+	current := sl.Head
 	if current == nil {
-		link.InsertAtHead(value)
+		sl.InsertAtHead(value)
 		return
 	}
 
@@ -43,65 +42,63 @@ func (link *SinglyLink[T]) InsertAtTail(value T) {
 	newNode.Next = nil
 	current.Next = newNode
 
-	link.length++
+	sl.length++
 }
 
 // InsertAt insert value into singly linklist at index
-func (link *SinglyLink[T]) InsertAt(index int, value T) error {
-	size := link.length
+// param `index` should between [0, len(SinglyLink)], if index do not meet the conditions, do nothing
+func (sl *SinglyLink[T]) InsertAt(index int, value T) {
+	size := sl.length
 	if index < 0 || index > size {
-		return errors.New("param index should between 0 and the length of singly link.")
+		return
 	}
 
 	if index == 0 {
-		link.InsertAtHead(value)
-		return nil
+		sl.InsertAtHead(value)
+		return
 	}
 
 	if index == size {
-		link.InsertAtTail(value)
-		return nil
+		sl.InsertAtTail(value)
+		return
 	}
 
 	i := 0
-	current := link.Head
+	current := sl.Head
 
 	for current != nil {
 		if i == index-1 {
 			newNode := datastructure.NewLinkNode(value)
 			newNode.Next = current.Next
 			current.Next = newNode
-			link.length++
-
-			return nil
+			sl.length++
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("singly link list no exist")
 }
 
 // DeleteAtHead delete value in singly linklist at head index
-func (link *SinglyLink[T]) DeleteAtHead() error {
-	if link.Head == nil {
-		return errors.New("singly link list no exist")
-	}
-	current := link.Head
-	link.Head = current.Next
-	link.length--
-
-	return nil
+func (sl *SinglyLink[T]) DeleteAtHead() {
+	if sl.Head == nil {
+		return
 	}
 
-// DeleteAtTail delete value in singly linklist at tail index
-func (link *SinglyLink[T]) DeleteAtTail() error {
-	if link.Head == nil {
-		return errors.New("singly link list no exist")
+	current := sl.Head
+	sl.Head = current.Next
+	sl.length--
 }
-	current := link.Head
+
+// DeleteAtTail delete value in singly linklist at tail
+func (sl *SinglyLink[T]) DeleteAtTail() {
+	if sl.Head == nil {
+		return
+	}
+
+	current := sl.Head
 	if current.Next == nil {
-		return link.DeleteAtHead()
+		sl.DeleteAtHead()
 	}
 
 	for current.Next.Next != nil {
@@ -109,68 +106,66 @@ func (link *SinglyLink[T]) DeleteAtTail() error {
 	}
 
 	current.Next = nil
-	link.length--
-	return nil
+	sl.length--
 }
 
 // DeleteAt delete value in singly linklist at index
-func (link *SinglyLink[T]) DeleteAt(index int) error {
-	if link.Head == nil {
-		return errors.New("singly link list no exist")
+// param `index` should be [0, len(SinglyLink)-1]
+func (sl *SinglyLink[T]) DeleteAt(index int) {
+	if sl.Head == nil {
+		return
 	}
-	current := link.Head
+	current := sl.Head
 	if current.Next == nil || index == 0 {
-		return link.DeleteAtHead()
+		sl.DeleteAtHead()
 	}
 
-	if index == link.length-1 {
-		return link.DeleteAtTail()
+	if index == sl.length-1 {
+		sl.DeleteAtTail()
 	}
 
-	if index < 0 || index > link.length-1 {
-		return errors.New("param index should between 0 and link size -1.")
+	if index < 0 || index > sl.length-1 {
+		return
 	}
 
 	i := 0
 	for current != nil {
 		if i == index-1 {
 			current.Next = current.Next.Next
-			link.length--
-			return nil
+			sl.length--
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("delete error")
 }
 
 // DeleteValue delete value in singly linklist
-func (link *SinglyLink[T]) DeleteValue(value T) {
-	if link.Head == nil {
+func (sl *SinglyLink[T]) DeleteValue(value T) {
+	if sl.Head == nil {
 		return
 	}
 	dummyHead := datastructure.NewLinkNode(value)
-	dummyHead.Next = link.Head
+	dummyHead.Next = sl.Head
 	current := dummyHead
 
 	for current.Next != nil {
 		if reflect.DeepEqual(current.Next.Value, value) {
 			current.Next = current.Next.Next
-			link.length--
+			sl.length--
 		} else {
 			current = current.Next
 		}
 	}
 
-	link.Head = dummyHead.Next
+	sl.Head = dummyHead.Next
 }
 
 // Reverse the linked list
-func (link *SinglyLink[T]) Reverse() {
+func (sl *SinglyLink[T]) Reverse() {
 	var pre, next *datastructure.LinkNode[T]
 
-	current := link.Head
+	current := sl.Head
 
 	for current != nil {
 		next = current.Next
@@ -179,19 +174,19 @@ func (link *SinglyLink[T]) Reverse() {
 		current = next
 	}
 
-	link.Head = pre
+	sl.Head = pre
 }
 
 // GetMiddleNode return node at middle index of linked list
-func (link *SinglyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
-	if link.Head == nil {
+func (sl *SinglyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
+	if sl.Head == nil {
 		return nil
 	}
-	if link.Head.Next == nil {
-		return link.Head
+	if sl.Head.Next == nil {
+		return sl.Head
 	}
-	fast := link.Head
-	slow := link.Head
+	fast := sl.Head
+	slow := sl.Head
 
 	for fast != nil {
 		fast = fast.Next
@@ -207,14 +202,14 @@ func (link *SinglyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
 }
 
 // Size return the count of singly linked list
-func (link *SinglyLink[T]) Size() int {
-	return link.length
+func (sl *SinglyLink[T]) Size() int {
+	return sl.length
 }
 
 // Values return slice of all singly linklist node value
-func (link *SinglyLink[T]) Values() []T {
+func (sl *SinglyLink[T]) Values() []T {
 	result := []T{}
-	current := link.Head
+	current := sl.Head
 	for current != nil {
 		result = append(result, current.Value)
 		current = current.Next
@@ -222,20 +217,20 @@ func (link *SinglyLink[T]) Values() []T {
 	return result
 }
 
-// IsEmpty checks if link is empty or not
-func (link *SinglyLink[T]) IsEmpty() bool {
-	return link.length == 0
+// IsEmpty checks if sl is empty or not
+func (sl *SinglyLink[T]) IsEmpty() bool {
+	return sl.length == 0
 }
 
 // Clear all the node in singly linklist
-func (link *SinglyLink[T]) Clear() {
-	link.Head = nil
-	link.length = 0
+func (sl *SinglyLink[T]) Clear() {
+	sl.Head = nil
+	sl.length = 0
 }
 
 // Print all nodes info of a linked list
-func (link *SinglyLink[T]) Print() {
-	current := link.Head
+func (sl *SinglyLink[T]) Print() {
+	current := sl.Head
 	info := "[ "
 	for current != nil {
 		info += fmt.Sprintf("%+v, ", current)

datastructure/link/singlylink_test.go

@@ -41,25 +41,12 @@ func TestSinglyLink_InsertAt(t *testing.T) {
 
 	link := NewSinglyLink[int]()
 
-	err := link.InsertAt(1, 1)
-	assert.IsNotNil(err)
+	link.InsertAt(1, 1) //do nothing
 
-	err = link.InsertAt(0, 1)
-	if err != nil {
-		t.FailNow()
-	}
-	err = link.InsertAt(1, 2)
-	if err != nil {
-		t.FailNow()
-	}
-	err = link.InsertAt(2, 4)
-	if err != nil {
-		t.FailNow()
-	}
-	err = link.InsertAt(2, 3)
-	if err != nil {
-		t.FailNow()
-	}
+	link.InsertAt(0, 1)
+	link.InsertAt(1, 2)
+	link.InsertAt(2, 4)
+	link.InsertAt(2, 3)
 
 	link.Print()
 
@@ -73,8 +60,8 @@ func TestSinglyLink_DeleteAtHead(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSinglyLink_DeleteAtHead")
 
 	link := NewSinglyLink[int]()
-	err := link.DeleteAtHead()
-	assert.IsNotNil(err)
+
+	link.DeleteAtHead()
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -94,8 +81,6 @@ func TestSinglyLink_DeleteAtTail(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSinglyLink_DeleteAtTail")
 
 	link := NewSinglyLink[int]()
-	err := link.DeleteAtTail()
-	assert.IsNotNil(err)
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -103,7 +88,6 @@ func TestSinglyLink_DeleteAtTail(t *testing.T) {
 	link.InsertAtTail(4)
 
 	link.DeleteAtTail()
-	link.Print()
 
 	expected := []int{1, 2, 3}
 	values := link.Values()
@@ -133,8 +117,6 @@ func TestSinglyLink_DeleteAt(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSinglyLink_DeleteAt")
 
 	link := NewSinglyLink[int]()
-	err := link.DeleteAt(0)
-	assert.IsNotNil(err)
 
 	link.InsertAtTail(1)
 	link.InsertAtTail(2)
@@ -142,11 +124,7 @@ func TestSinglyLink_DeleteAt(t *testing.T) {
 	link.InsertAtTail(4)
 	link.InsertAtTail(5)
 
-	err = link.DeleteAt(5)
-	assert.IsNotNil(err)
-
-	err = link.DeleteAt(0)
-	assert.IsNil(err)
+	link.DeleteAt(0)
 	assert.Equal([]int{2, 3, 4, 5}, link.Values())
 
 	link.DeleteAt(3)
@@ -167,7 +145,6 @@ func TestSinglyLink_Reverse(t *testing.T) {
 	link.InsertAtTail(4)
 
 	link.Reverse()
-	link.Print()
 	assert.Equal([]int{4, 3, 2, 1}, link.Values())
 }
 

datastructure/list/list.go

@@ -156,7 +156,7 @@ func (l *List[T]) DeleteAt(index int) {
 		return
 	}
 	if index == size-1 {
-		data = append(data[:index])
+		data = data[:index]
 	} else {
 		data = append(data[:index], data[index+1:]...)
 	}
@@ -174,7 +174,7 @@ func (l *List[T]) DeleteIf(f func(T) bool) int {
 			continue
 		}
 		if index == size-1 {
-			data = append(data[:index])
+			data = data[:index]
 		} else {
 			data = append(data[:index], data[index+1:]...)
 			index--
@@ -221,7 +221,7 @@ func (l *List[T]) IsEmpty() bool {
 
 // Clear the data of list
 func (l *List[T]) Clear() {
-	l.data = make([]T, 0, 0)
+	l.data = make([]T, 0)
 }
 
 // Clone return a copy of list
@@ -235,7 +235,7 @@ func (l *List[T]) Clone() *List[T] {
 // Merge two list, return new list, don't change original list
 func (l *List[T]) Merge(other *List[T]) *List[T] {
 	l1, l2 := len(l.data), len(other.data)
-	ml := NewList(make([]T, l1+l2, l1+l2))
+	ml := NewList(make([]T, l1+l2))
 
 	data := append([]T{}, append(l.data, other.data...)...)
 	ml.data = data
@@ -274,7 +274,7 @@ func (l *List[T]) Unique() {
 	data := l.data
 	size := len(data)
 
-	uniqueData := make([]T, 0, 0)
+	uniqueData := make([]T, 0)
 	for i := 0; i < size; i++ {
 		value := data[i]
 		skip := true
@@ -305,7 +305,7 @@ func (l *List[T]) Union(other *List[T]) *List[T] {
 
 // Intersection creates a new list whose element both be contained in list l and other
 func (l *List[T]) Intersection(other *List[T]) *List[T] {
-	result := NewList(make([]T, 0, 0))
+	result := NewList(make([]T, 0))
 
 	for _, v := range l.data {
 		if other.Contain(v) {

datastructure/queue/arrayqueue_test.go

@@ -18,8 +18,6 @@ func TestArrayQueue_Enqueue(t *testing.T) {
 	data := queue.Data()
 	size := queue.Size()
 
-	queue.Print()
-
 	assert.Equal(expected, data)
 	assert.Equal(3, size)
 }
@@ -35,7 +33,6 @@ func TestArrayQueue_Dequeue(t *testing.T) {
 	val, ok := queue.Dequeue()
 	assert.Equal(true, ok)
 
-	queue.Print()
 	assert.Equal(1, val)
 	assert.Equal([]int{2, 3}, queue.Data())
 }
@@ -50,8 +47,6 @@ func TestArrayQueue_Front(t *testing.T) {
 
 	val := queue.Front()
 
-	queue.Print()
-
 	assert.Equal(1, val)
 	assert.Equal([]int{1, 2, 3}, queue.Data())
 }
@@ -66,8 +61,6 @@ func TestArrayQueue_Back(t *testing.T) {
 
 	val := queue.Back()
 
-	queue.Print()
-
 	assert.Equal(3, val)
 	assert.Equal([]int{1, 2, 3}, queue.Data())
 }

datastructure/queue/circularqueue_test.go

@@ -10,31 +10,43 @@ func TestCircularQueue_Enqueue(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_Enqueue")
 
 	queue := NewCircularQueue[int](6)
-	queue.Enqueue(1)
-	queue.Enqueue(2)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
 
-	queue.Print()
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(2)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(3)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(4)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(5)
+	assert.IsNil(err)
+
 	assert.Equal([]int{1, 2, 3, 4, 5}, queue.Data())
 	assert.Equal(5, queue.Size())
 
-	err := queue.Enqueue(6)
+	err = queue.Enqueue(6)
 	assert.IsNotNil(err)
 }
 
 func TestCircularQueue_Dequeue(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_DeQueue")
 
-	queue := NewCircularQueue[int](6)
+	queue := NewCircularQueue[int](4)
 	assert.Equal(true, queue.IsEmpty())
 
-	queue.Enqueue(1)
-	queue.Enqueue(2)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(2)
+	assert.IsNil(err)
+
+	err = queue.Enqueue(3)
+	assert.IsNil(err)
 
 	val, err := queue.Dequeue()
 	assert.IsNil(err)
@@ -43,11 +55,7 @@ func TestCircularQueue_Dequeue(t *testing.T) {
 	assert.Equal(false, queue.IsFull())
 
 	val, _ = queue.Dequeue()
-	queue.Print()
 	assert.Equal(2, *val)
-
-	queue.Enqueue(6)
-	queue.Print()
 	assert.Equal(false, queue.IsFull())
 }
 
@@ -55,55 +63,52 @@ func TestCircularQueue_Front(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_Front")
 
 	queue := NewCircularQueue[int](6)
-	queue.Enqueue(1)
-	queue.Enqueue(2)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
 
-	queue.Print()
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
 
-	queue.Dequeue()
-	queue.Dequeue()
-	queue.Enqueue(6)
-	queue.Enqueue(7)
+	err = queue.Enqueue(2)
+	assert.IsNil(err)
 
-	queue.Print()
+	err = queue.Enqueue(3)
+	assert.IsNil(err)
 
 	val := queue.Front()
-	assert.Equal(3, val)
-	assert.Equal(5, queue.Size())
+	assert.IsNil(err)
+	assert.Equal(1, val)
+	assert.Equal(3, queue.Size())
 }
 
 func TestCircularQueue_Back(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_Back")
 
-	queue := NewCircularQueue[int](6)
+	queue := NewCircularQueue[int](3)
 	assert.Equal(true, queue.IsEmpty())
 
-	queue.Enqueue(1)
-	queue.Enqueue(2)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
 
-	queue.Print()
-	assert.Equal(5, queue.Back())
+	err = queue.Enqueue(2)
+	assert.IsNil(err)
 
-	queue.Dequeue()
-	queue.Dequeue()
-	queue.Enqueue(6)
-	queue.Enqueue(7)
+	assert.Equal(2, queue.Back())
 
-	queue.Print()
-	assert.Equal(7, queue.Back())
+	val, _ := queue.Dequeue()
+	assert.Equal(1, *val)
+
+	err = queue.Enqueue(3)
+	assert.IsNil(err)
+
+	assert.Equal(3, queue.Back())
 }
 
 func TestCircularQueue_Contain(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_Contain")
 
 	queue := NewCircularQueue[int](2)
-	queue.Enqueue(1)
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
+
 	assert.Equal(true, queue.Contain(1))
 	assert.Equal(false, queue.Contain(2))
 }
@@ -115,7 +120,9 @@ func TestCircularQueue_Clear(t *testing.T) {
 	assert.Equal(true, queue.IsEmpty())
 	assert.Equal(0, queue.Size())
 
-	queue.Enqueue(1)
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
+
 	assert.Equal(false, queue.IsEmpty())
 	assert.Equal(1, queue.Size())
 
@@ -127,22 +134,12 @@ func TestCircularQueue_Clear(t *testing.T) {
 func TestCircularQueue_Data(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCircularQueue_Data")
 
-	queue := NewCircularQueue[int](6)
-	queue.Enqueue(1)
-	queue.Enqueue(2)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
+	queue := NewCircularQueue[int](3)
+	err := queue.Enqueue(1)
+	assert.IsNil(err)
 
-	queue.Print()
-	assert.Equal([]int{1, 2, 3, 4, 5}, queue.Data())
-
-	queue.Dequeue()
-	queue.Dequeue()
-	queue.Enqueue(6)
-	queue.Enqueue(7)
-
-	queue.Print()
-	assert.Equal([]int{3, 4, 5, 6, 7}, queue.Data())
+	err = queue.Enqueue(2)
+	assert.IsNil(err)
 
+	assert.Equal([]int{1, 2}, queue.Data())
 }

datastructure/queue/linkedqueue_test.go

@@ -14,8 +14,6 @@ func TestLinkedQueue_Enqueue(t *testing.T) {
 	queue.Enqueue(2)
 	queue.Enqueue(3)
 
-	queue.Print()
-
 	assert.Equal([]int{1, 2, 3}, queue.Data())
 	assert.Equal(3, queue.Size())
 }

datastructure/queue/priorityqueue_test.go

@@ -23,19 +23,24 @@ func TestPriorityQueue_Enqueue(t *testing.T) {
 	assert := internal.NewAssert(t, "TestPriorityQueue_Enqueue")
 
 	comparator := &intComparator{}
-	pq := NewPriorityQueue[int](10, comparator)
+	pq := NewPriorityQueue[int](3, comparator)
 
 	assert.Equal(true, pq.IsEmpty())
 	assert.Equal(false, pq.IsFull())
 
-	for i := 1; i < 11; i++ {
-		pq.Enqueue(i)
-	}
+	err := pq.Enqueue(1)
+	assert.IsNil(err)
+
+	err = pq.Enqueue(2)
+	assert.IsNil(err)
+
+	err = pq.Enqueue(3)
+	assert.IsNil(err)
 
 	assert.Equal(true, pq.IsFull())
 
 	queueData := pq.Data()
-	assert.Equal([]int{10, 9, 6, 7, 8, 2, 5, 1, 4, 3}, queueData)
+	assert.Equal([]int{3, 1, 2}, queueData)
 
 }
 
@@ -43,22 +48,23 @@ func TestPriorityQueue_Dequeue(t *testing.T) {
 	assert := internal.NewAssert(t, "TestPriorityQueue_Dequeue")
 
 	comparator := &intComparator{}
-	pq := NewPriorityQueue[int](10, comparator)
+	pq := NewPriorityQueue[int](3, comparator)
 
 	_, ok := pq.Dequeue()
 	assert.Equal(false, ok)
 
-	for i := 1; i < 11; i++ {
-		pq.Enqueue(i)
-	}
+	err := pq.Enqueue(1)
+	assert.IsNil(err)
 
-	assert.Equal(10, pq.Size())
+	err = pq.Enqueue(2)
+	assert.IsNil(err)
+
+	err = pq.Enqueue(3)
+	assert.IsNil(err)
+
+	assert.Equal(3, pq.Size())
 
 	val, ok := pq.Dequeue()
 	assert.Equal(true, ok)
-	assert.Equal(10, val)
-
-	assert.Equal([]int{9, 8, 6, 7, 3, 2, 5, 1, 4}, pq.Data())
-
-	assert.Equal(9, pq.Size())
+	assert.Equal(3, val)
 }

datastructure/stack/linkedstack_test.go

@@ -14,8 +14,6 @@ func TestLinkedStack_Push(t *testing.T) {
 	stack.Push(2)
 	stack.Push(3)
 
-	stack.Print()
-
 	expected := []int{3, 2, 1}
 	values := stack.Data()
 	size := stack.Size()

datastructure/tree/bstree_test.go

@@ -27,8 +27,6 @@ func TestBSTree_Insert(t *testing.T) {
 	bstree.Insert(5)
 	bstree.Insert(2)
 	bstree.Insert(4)
-
-	bstree.Print()
 }
 
 func TestBSTree_PreOrderTraverse(t *testing.T) {
@@ -86,8 +84,6 @@ func TestBSTree_LevelOrderTraverse(t *testing.T) {
 	bstree.Insert(2)
 	bstree.Insert(4)
 
-	bstree.Print()
-
 	acturl := bstree.LevelOrderTraverse()
 	t.Log(acturl)
 	assert.Equal([]int{6, 5, 7, 2, 4}, acturl)
@@ -103,10 +99,8 @@ func TestBSTree_Delete(t *testing.T) {
 	bstree.Insert(2)
 	bstree.Insert(4)
 
-	bstree.Print()
-
 	bstree.Delete(4)
-	bstree.Print()
+
 	acturl1 := bstree.InOrderTraverse()
 	t.Log(acturl1)
 	assert.Equal([]int{2, 5, 6, 7}, acturl1)
@@ -129,8 +123,6 @@ func TestBSTree_Depth(t *testing.T) {
 	bstree.Insert(2)
 	bstree.Insert(4)
 
-	bstree.Print()
-
 	assert.Equal(bstree.Depth(), 4)
 }
 
@@ -150,8 +142,6 @@ func TestBSTree_IsSubTree(t *testing.T) {
 	subTree.Insert(4)
 	subTree.Insert(6)
 
-	subTree.Print()
-
 	assert.Equal(true, superTree.HasSubTree(subTree))
 	assert.Equal(false, subTree.HasSubTree(superTree))
 }

datastructure/tree/tree_internal.go

@@ -38,35 +38,35 @@ func inOrderTraverse[T any](node *datastructure.TreeNode[T]) []T {
 	return data
 }
 
-func preOrderPrint[T any](node *datastructure.TreeNode[T]) {
-	if node == nil {
-		return
-	}
+// func preOrderPrint[T any](node *datastructure.TreeNode[T]) {
+// 	if node == nil {
+// 		return
+// 	}
 
-	fmt.Printf("%v, ", node.Value)
-	preOrderPrint(node.Left)
-	preOrderPrint(node.Right)
-}
+// 	fmt.Printf("%v, ", node.Value)
+// 	preOrderPrint(node.Left)
+// 	preOrderPrint(node.Right)
+// }
 
-func postOrderPrint[T any](node *datastructure.TreeNode[T]) {
-	if node == nil {
-		return
-	}
+// func postOrderPrint[T any](node *datastructure.TreeNode[T]) {
+// 	if node == nil {
+// 		return
+// 	}
 
-	preOrderPrint(node.Left)
-	preOrderPrint(node.Right)
-	fmt.Printf("%v, ", node.Value)
-}
+// 	postOrderPrint(node.Left)
+// 	postOrderPrint(node.Right)
+// 	fmt.Printf("%v, ", node.Value)
+// }
 
-func inOrderPrint[T any](node *datastructure.TreeNode[T]) {
-	if node == nil {
-		return
-	}
+// func inOrderPrint[T any](node *datastructure.TreeNode[T]) {
+// 	if node == nil {
+// 		return
+// 	}
 
-	inOrderPrint(node.Left)
-	fmt.Printf("%v, ", node.Value)
-	inOrderPrint(node.Right)
-}
+// 	inOrderPrint(node.Left)
+// 	fmt.Printf("%v, ", node.Value)
+// 	inOrderPrint(node.Right)
+// }
 
 func levelOrderTraverse[T any](root *datastructure.TreeNode[T], traversal *[]T) {
 	var q []*datastructure.TreeNode[T] // queue

docs/datastructure/linklist.md

@@ -132,12 +132,12 @@ func main() {
 
 
 ### <span id="SinglyLink_InsertAt">InsertAt</span>
-<p>Insert value into singly linklist at index, index shoud be great or equal 0 and less or equal number of link nodes</p>
+<p>Insert value into singly linklist at index, param `index` should between [0, len(SinglyLink)], if index do not meet the conditions, do nothing</p>
 
 <b>Signature:</b>
 
 ```go
-func (link *SinglyLink[T]) InsertAt(index int, value T) error
+func (link *SinglyLink[T]) InsertAt(index int, value T)
 ```
 <b>Example:</b>
 
@@ -152,6 +152,8 @@ import (
 func main() {
     lk := link.NewSinglyLink[int]()
 
+    lk.InsertAt(1, 1) //do nothing
+    
     lk.InsertAt(0, 1)
     lk.InsertAt(1, 2)
     lk.InsertAt(2, 3)
@@ -228,12 +230,12 @@ func main() {
 
 
 ### <span id="SinglyLink_DeleteAt">DeleteAt</span>
-<p>Delete value at specific index, index shoud be great or equal 0 and less or less than number of link nodes - 1</p>
+<p>Delete value at specific index, param `index` should be [0, len(SinglyLink)-1]</p>
 
 <b>Signature:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAt(index int) error
+func (link *SinglyLink[T]) DeleteAt(index int)
 ```
 <b>Example:</b>
 
@@ -253,9 +255,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAt(3)
+    lk.DeleteAt(3)
 
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2, 3}
 }
 ```
@@ -268,7 +269,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAtHead() error
+func (link *SinglyLink[T]) DeleteAtHead()
 ```
 <b>Example:</b>
 
@@ -288,9 +289,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAtHead()
+    lk.DeleteAtHead()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{2, 3, 4}
 }
 ```
@@ -304,7 +304,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAtTail() error
+func (link *SinglyLink[T]) DeleteAtTail()
 ```
 <b>Example:</b>
 
@@ -323,9 +323,8 @@ func main() {
     lk.InsertAtTail(2)
     lk.InsertAtTail(3)
 
-    err := lk.DeleteAtTail()
+    lk.DeleteAtTail()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2}
 }
 ```
@@ -628,12 +627,12 @@ func main() {
 
 
 ### <span id="DoublyLink_InsertAt">InsertAt</span>
-<p>Insert value into doubly linklist at index, index shoud be great or equal 0 and less or equal number of link nodes</p>
+<p>Insert value into doubly linklist at index, param `index` should between [0, len(DoublyLink)], if index do not meet the conditions, do nothing</p>
 
 <b>Signature:</b>
 
 ```go
-func (link *DoublyLink[T]) InsertAt(index int, value T) error
+func (link *DoublyLink[T]) InsertAt(index int, value T)
 ```
 <b>Example:</b>
 
@@ -648,6 +647,8 @@ import (
 func main() {
     lk := link.NewDoublyLink[int]()
 
+    lk.InsertAt(1, 1) //do nothing
+
     lk.InsertAt(0, 1)
     lk.InsertAt(1, 2)
     lk.InsertAt(2, 3)
@@ -724,12 +725,12 @@ func main() {
 
 
 ### <span id="DoublyLink_DeleteAt">DeleteAt</span>
-<p>Delete value at specific index, index shoud be great or equal 0 and less or less than number of link nodes - 1</p>
+<p>Delete value at specific index, param `index` should be [0, len(DoublyLink)-1]</p>
 
 <b>Signature:</b>
 
 ```go
-func (link *DoublyLink[T]) DeleteAt(index int) error
+func (link *DoublyLink[T]) DeleteAt(index int)
 ```
 <b>Example:</b>
 
@@ -749,9 +750,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAt(3)
+    lk.DeleteAt(3)
 
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2, 3}
 }
 ```
@@ -764,7 +764,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (link *DoublyLink[T]) DeleteAtHead() error
+func (link *DoublyLink[T]) DeleteAtHead()
 ```
 <b>Example:</b>
 
@@ -784,9 +784,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAtHead()
+    lk.DeleteAtHead()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{2, 3, 4}
 }
 ```

docs/datastructure/linklist_zh-CN.md

@@ -137,7 +137,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *SinglyLink[T]) InsertAt(index int, value T) error
+func (link *SinglyLink[T]) InsertAt(index int, value T)
 ```
 <b>例子:</b>
 
@@ -152,6 +152,8 @@ import (
 func main() {
     lk := link.NewSinglyLink[int]()
 
+    lk.InsertAt(1, 1) //do nothing
+
     lk.InsertAt(0, 1)
     lk.InsertAt(1, 2)
     lk.InsertAt(2, 3)
@@ -233,7 +235,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAt(index int) error
+func (link *SinglyLink[T]) DeleteAt(index int)
 ```
 <b>例子:</b>
 
@@ -253,9 +255,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAt(3)
+    lk.DeleteAt(3)
 
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2, 3}
 }
 ```
@@ -268,7 +269,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAtHead() error
+func (link *SinglyLink[T]) DeleteAtHead()
 ```
 <b>例子:</b>
 
@@ -288,9 +289,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAtHead()
+    lk.DeleteAtHead()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{2, 3, 4}
 }
 ```
@@ -304,7 +304,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *SinglyLink[T]) DeleteAtTail() error
+func (link *SinglyLink[T]) DeleteAtTail()
 ```
 <b>例子:</b>
 
@@ -323,9 +323,8 @@ func main() {
     lk.InsertAtTail(2)
     lk.InsertAtTail(3)
 
-    err := lk.DeleteAtTail()
+    lk.DeleteAtTail()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2}
 }
 ```
@@ -633,7 +632,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *DoublyLink[T]) InsertAt(index int, value T) error
+func (link *DoublyLink[T]) InsertAt(index int, value T)
 ```
 <b>例子:</b>
 
@@ -648,6 +647,8 @@ import (
 func main() {
     lk := link.NewDoublyLink[int]()
 
+    lk.InsertAt(1, 1) //do nothing
+
     lk.InsertAt(0, 1)
     lk.InsertAt(1, 2)
     lk.InsertAt(2, 3)
@@ -729,7 +730,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *DoublyLink[T]) DeleteAt(index int) error
+func (link *DoublyLink[T]) DeleteAt(index int)
 ```
 <b>例子:</b>
 
@@ -749,9 +750,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAt(3)
+    lk.DeleteAt(3)
 
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2, 3}
 }
 ```
@@ -764,7 +764,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *DoublyLink[T]) DeleteAtHead() error
+func (link *DoublyLink[T]) DeleteAtHead()
 ```
 <b>例子:</b>
 
@@ -784,9 +784,8 @@ func main() {
     lk.InsertAtTail(3)
     lk.InsertAtTail(4)
 
-    err := lk.DeleteAtHead()
+    lk.DeleteAtHead()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{2, 3, 4}
 }
 ```
@@ -800,7 +799,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (link *DoublyLink[T]) DeleteAtTail() error
+func (link *DoublyLink[T]) DeleteAtTail()
 ```
 <b>例子:</b>
 
@@ -819,9 +818,8 @@ func main() {
     lk.InsertAtTail(2)
     lk.InsertAtTail(3)
 
-    err := lk.DeleteAtTail()
+    lk.DeleteAtTail()
     
-    fmt.Println(err) //nil
     fmt.Println(lk.Values()) //[]int{1, 2}
 }
 ```

docs/formatter.md

@@ -28,13 +28,12 @@ import (
 
 
 ### <span id="Comma">Comma</span>
-<p>Add comma to number by every 3 numbers from right. ahead by symbol char.
-Param should be number or numberic string.</p>
+<p>Add comma to a number value by every 3 numbers from right to left. ahead by symbol char. if value is a invalid number string like "aa", return empty string.</p>
 
 <b>Signature:</b>
 
 ```go
-func Comma(v any, symbol string) string
+func Comma[T constraints.Float | constraints.Integer | string](value T, symbol string) string
 ```
 <b>Example:</b>
 

docs/formatter_zh-CN.md

@@ -28,12 +28,12 @@ import (
 
 
 ### <span id="Comma">Comma</span>
-<p>用逗号每隔3位分割数字/字符串，签名添加符号。参数必须是数字或者可以转为数字的字符串</p>
+<p>用逗号每隔3位分割数字/字符串，支持前缀添加符号。参数value必须是数字或者可以转为数字的字符串, 否则返回空字符串</p>
 
 <b>函数签名:</b>
 
 ```go
-func Comma(v any, symbol string) string
+func Comma[T constraints.Float | constraints.Integer | string](value T, symbol string) string
 ```
 <b>例子:</b>
 

docs/mathutil.md

@@ -45,7 +45,7 @@ import (
 <b>Signature:</b>
 
 ```go
-func Average[T lancetconstraints.Number](numbers ...T) T
+func Average[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>Example:</b>
 
@@ -157,7 +157,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func Max[T lancetconstraints.Number](numbers ...T) T
+func Max[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>Example:</b>
 
@@ -223,7 +223,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func Min[T lancetconstraints.Number](numbers ...T) T
+func Min[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>Example:</b>
 

docs/mathutil_zh-CN.md

@@ -44,7 +44,7 @@ import (
 <b>函数签名:</b>
 
 ```go
-func Average[T lancetconstraints.Number](numbers ...T) T
+func Average[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>例子:</b>
 
@@ -154,7 +154,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func Max[T lancetconstraints.Number](numbers ...T) T
+func Max[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>例子:</b>
 
@@ -220,7 +220,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func Min[T lancetconstraints.Number](numbers ...T) T
+func Min[T constraints.Integer | constraints.Float](numbers ...T) T
 ```
 <b>例子:</b>
 

docs/slice.md

@@ -1138,7 +1138,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func Sort[T lancetconstraints.Ordered](slice []T, sortOrder ...string)
+func Sort[T constraints.Ordered](slice []T, sortOrder ...string)
 ```
 
 <b>Example:</b>

docs/slice_zh-CN.md

@@ -1135,7 +1135,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func Sort[T lancetconstraints.Ordered](slice []T, sortOrder ...string)
+func Sort[T constraints.Ordered](slice []T, sortOrder ...string)
 ```
 
 <b>例子:</b>

docs/system.md

@@ -211,7 +211,7 @@ func main() {
 
 
 ### <span id="ExecCommand">CompareOsEnv</span>
-<p>Use shell /bin/bash -c(linux) or cmd (windows) to execute command.</p>
+<p>Execute shell command, return the stdout and stderr string of command, and error if error occur. param `command` is a complete command string, like, ls -a (linux), dir(windows), ping 127.0.0.1. In linux, use /bin/bash -c to execute command, In windows, use powershell.exe to execute command.</p>
 
 <b>Signature:</b>
 
@@ -227,10 +227,24 @@ import (
 )
 
 func main() {
-	out, errout, err := system.ExecCommand("ls")
-	fmt.Println(out)
-	fmt.Println(errout)
-	fmt.Println(err)
+	// linux or mac
+	stdout, stderr, err := system.ExecCommand("ls")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+	assert.Equal("", stderr)
+
+	// windows
+	stdout, stderr, err = system.ExecCommand("dir")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+
+	// error command
+	stdout, stderr, err = system.ExecCommand("abc")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+	if err != nil {
+		fmt.Println(err.Error())
+	}
 }
 ```
 

docs/system_zh-CN.md

@@ -212,7 +212,7 @@ func main() {
 
 
 ### <span id="ExecCommand">ExecCommand</span>
-<p>使用shell /bin/bash -c(linux) 或 cmd (windows) 执行shell命令</p>
+<p>执行shell命令，返回命令的stdout和stderr字符串，如果出现错误，则返回错误。参数`command`是一个完整的命令字符串，如ls-a（linux），dir（windows），ping 127.0.0.1。在linux中，使用/bin/bash-c执行命令，在windows中，使用powershell.exe执行命令。</p>
 
 <b>Signature:</b>
 
@@ -228,10 +228,24 @@ import (
 )
 
 func main() {
-	out, errout, err := system.ExecCommand("ls")
-	fmt.Println(out)
-	fmt.Println(errout)
-	fmt.Println(err)
+	// linux or mac
+	stdout, stderr, err := system.ExecCommand("ls")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+	assert.Equal("", stderr)
+
+	// windows
+	stdout, stderr, err = system.ExecCommand("dir")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+
+	// error command
+	stdout, stderr, err = system.ExecCommand("abc")
+	fmt.Println("std out: ", stdout)
+	fmt.Println("std err: ", stderr)
+	if err != nil {
+		fmt.Println(err.Error())
+	}
 }
 ```
 

docs/validator.md

@@ -47,6 +47,7 @@ import (
 - [IsUrl](#IsUrl)
 - [IsWeakPassword](#IsWeakPassword)
 - [IsZeroValue](#IsZeroValue)
+- [IsGBK](#IsGBK)
   
 
 <div STYLE="page-break-after: always;"></div>
@@ -821,7 +822,34 @@ func main() {
 ```
 
 
-
+### <span id="IsGBK">IsGBK</span>
+<p>Checks if data encoding is gbk(Chinese character internal code extension specification). this function is implemented by whether double bytes fall within the encoding range of gbk,while each byte of utf-8 encoding format falls within the encoding range of gbk.Therefore, utf8.valid() should be called first to check whether it is not utf-8 encoding and then call IsGBK() to check gbk encoding. like the example.</p>
+
+<b>Signature:</b>
+
+```go
+func IsGBK(data []byte) bool
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/validator"
+)
+
+func main() {
+	data := []byte("你好")
+	
+	// check utf8 first
+	if utf8.Valid(data) {
+		fmt.Println("data encoding is utf-8")
+	}else if(validator.IsGBK(data)) {
+		fmt.Println("data encoding is GBK")
+	}
+	fmt.Println("data encoding is unknown")
+}
+```
 
 
 

docs/validator_zh-CN.md

@@ -47,6 +47,7 @@ import (
 - [IsUrl](#IsUrl)
 - [IsWeakPassword](#IsWeakPassword)
 - [IsZeroValue](#IsZeroValue)
+- [IsGBK](#IsGBK)
   
 
 <div STYLE="page-break-after: always;"></div>
@@ -820,3 +821,31 @@ func main() {
 }
 ```
 
+### <span id="IsGBK">IsGBK</span>
+<p>检查数据编码是否为gbk（汉字内部代码扩展规范）。该函数的实现取决于双字节是否在gbk的编码范围内，而utf-8编码格式的每个字节都在gbk编码范围内。因此，应该首先调用utf8.valid检查它是否是utf-8编码，然后调用IsGBK检查gbk编码。如示例所示。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsGBK(data []byte) bool
+```
+<b>例子:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/validator"
+)
+
+func main() {
+	data := []byte("你好")
+	
+	// 先检查utf8编码
+	if utf8.Valid(data) {
+		fmt.Println("data encoding is utf-8")
+	}else if(validator.IsGBK(data)) {
+		fmt.Println("data encoding is GBK")
+	}
+	fmt.Println("data encoding is unknown")
+}
+```

fileutil/file.go

@@ -11,7 +11,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"path"
@@ -78,13 +77,16 @@ func CopyFile(srcFilePath string, dstFilePath string) error {
 	var tmp = make([]byte, 1024*4)
 	for {
 		n, err := srcFile.Read(tmp)
-		distFile.Write(tmp[:n])
 		if err != nil {
 			if err == io.EOF {
 				return nil
 			}
 			return err
 		}
+		_, err = distFile.Write(tmp[:n])
+		if err != nil {
+			return err
+		}
 	}
 }
 
@@ -102,7 +104,7 @@ func ClearFile(path string) error {
 
 //ReadFileToString return string of file content
 func ReadFileToString(path string) (string, error) {
-	bytes, err := ioutil.ReadFile(path)
+	bytes, err := os.ReadFile(path)
 	if err != nil {
 		return "", err
 	}
@@ -141,7 +143,7 @@ func ListFileNames(path string) ([]string, error) {
 		return []string{}, nil
 	}
 
-	fs, err := ioutil.ReadDir(path)
+	fs, err := os.ReadDir(path)
 	if err != nil {
 		return []string{}, err
 	}
@@ -172,7 +174,7 @@ func Zip(fpath string, destPath string) error {
 	archive := zip.NewWriter(zipFile)
 	defer archive.Close()
 
-	filepath.Walk(fpath, func(path string, info os.FileInfo, err error) error {
+	err = filepath.Walk(fpath, func(path string, info os.FileInfo, err error) error {
 		if err != nil {
 			return err
 		}
@@ -209,6 +211,10 @@ func Zip(fpath string, destPath string) error {
 		return nil
 	})
 
+	if err != nil {
+		return err
+	}
+
 	return nil
 }
 
@@ -229,9 +235,13 @@ func UnZip(zipFile string, destPath string) error {
 		}
 
 		if f.FileInfo().IsDir() {
-			os.MkdirAll(path, os.ModePerm)
+			err = os.MkdirAll(path, os.ModePerm)
+			if err != nil {
+				return err
+			}
 		} else {
-			if err = os.MkdirAll(filepath.Dir(path), os.ModePerm); err != nil {
+			err = os.MkdirAll(filepath.Dir(path), os.ModePerm)
+			if err != nil {
 				return err
 			}
 

fileutil/file_test.go

@@ -25,9 +25,10 @@ func TestCreateFile(t *testing.T) {
 	f := "./text.txt"
 	if CreateFile(f) {
 		file, err := os.Open(f)
-		defer file.Close()
 		assert.IsNil(err)
 		assert.Equal(f, file.Name())
+
+		defer file.Close()
 	} else {
 		t.FailNow()
 	}
@@ -113,7 +114,11 @@ func TestReadFileToString(t *testing.T) {
 
 	f, _ := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0777)
 	defer f.Close()
-	f.WriteString("hello world")
+
+	_, err := f.WriteString("hello world")
+	if err != nil {
+		t.Log(err)
+	}
 
 	content, _ := ReadFileToString(path)
 	assert.Equal("hello world", content)
@@ -130,9 +135,12 @@ func TestClearFile(t *testing.T) {
 	f, _ := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0777)
 	defer f.Close()
 
-	f.WriteString("hello world")
+	_, err := f.WriteString("hello world")
+	if err != nil {
+		t.Log(err)
+	}
 
-	err := ClearFile(path)
+	err = ClearFile(path)
 	assert.IsNil(err)
 
 	content, _ := ReadFileToString(path)
@@ -148,8 +156,13 @@ func TestReadFileByLine(t *testing.T) {
 	CreateFile(path)
 
 	f, _ := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0777)
+
 	defer f.Close()
-	f.WriteString("hello\nworld")
+
+	_, err := f.WriteString("hello\nworld")
+	if err != nil {
+		t.Log(err)
+	}
 
 	expected := []string{"hello", "world"}
 	actual, _ := ReadFileByLine(path)
@@ -166,10 +179,14 @@ func TestZipAndUnZip(t *testing.T) {
 
 	file, _ := os.OpenFile(srcFile, os.O_WRONLY|os.O_TRUNC, 0777)
 	defer file.Close()
-	file.WriteString("hello\nworld")
+
+	_, err := file.WriteString("hello\nworld")
+	if err != nil {
+		t.Fail()
+	}
 
 	zipFile := "./text.zip"
-	err := Zip(srcFile, zipFile)
+	err = Zip(srcFile, zipFile)
 	assert.IsNil(err)
 
 	unZipPath := "./unzip"

formatter/formatter.go

@@ -4,14 +4,25 @@
 // Package formatter implements some functions to format string, struct.
 package formatter
 
-import "strings"
+import (
+	"strings"
+
+	"golang.org/x/exp/constraints"
+)
+
+// Comma add comma to a number value by every 3 numbers from right. ahead by symbol char.
+// if value is invalid number string eg "aa", return empty string
+// Comma("12345", "$") => "$12,345", Comma(12345, "$") => "$12,345"
+func Comma[T constraints.Float | constraints.Integer | string](value T, symbol string) string {
+	s, err := numberToString(value)
+	if err != nil {
+		return ""
+	}
 
-// Comma add comma to number by every 3 numbers from right. ahead by symbol char
-func Comma(v any, symbol string) string {
-	s := numString(v)
 	dotIndex := strings.Index(s, ".")
 	if dotIndex != -1 {
 		return symbol + commaString(s[:dotIndex]) + s[dotIndex:]
 	}
+
 	return symbol + commaString(s)
 }

formatter/formatter_internal.go

@@ -14,27 +14,34 @@ func commaString(s string) string {
 	return commaString(s[:len(s)-3]) + "," + commaString(s[len(s)-3:])
 }
 
-func numString(value any) string {
+func numberToString(value any) (string, error) {
 	switch reflect.TypeOf(value).Kind() {
-	case reflect.Int, reflect.Int64, reflect.Float32, reflect.Float64:
-		return fmt.Sprintf("%v", value)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+		reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return fmt.Sprintf("%v", value), nil
+
+		// todo: need to handle 12345678.9 => 1.23456789e+07
+	case reflect.Float32, reflect.Float64:
+		return fmt.Sprintf("%v", value), nil
+
 	case reflect.String:
 		{
 			sv := fmt.Sprintf("%v", value)
 			if strings.Contains(sv, ".") {
 				_, err := strconv.ParseFloat(sv, 64)
-				if err == nil {
-					return sv
+				if err != nil {
+					return "", err
 				}
+				return sv, nil
 			} else {
 				_, err := strconv.ParseInt(sv, 10, 64)
-				if err == nil {
-					return sv
+				if err != nil {
+					return "", nil
 				}
+				return sv, nil
 			}
 		}
 	default:
-		return ""
+		return "", nil
 	}
-	return ""
 }

formatter/formatter_test.go

@@ -12,12 +12,16 @@ func TestComma(t *testing.T) {
 	assert.Equal("", Comma("", ""))
 	assert.Equal("", Comma("aa", ""))
 	assert.Equal("", Comma("aa.a", ""))
-	assert.Equal("", Comma([]int{1}, ""))
 	assert.Equal("123", Comma("123", ""))
 	assert.Equal("12,345", Comma("12345", ""))
+	assert.Equal("12,345.6789", Comma("12345.6789", ""))
+	assert.Equal("123,456,789,000", Comma("123456789000", ""))
 
 	assert.Equal("12,345", Comma(12345, ""))
 	assert.Equal("$12,345", Comma(12345, "$"))
 	assert.Equal("¥12,345", Comma(12345, "¥"))
 	assert.Equal("12,345.6789", Comma(12345.6789, ""))
+	assert.Equal("12,345.6789", Comma(+12345.6789, ""))
+	// assert.Equal("12,345,678.9", Comma(12345678.9, ""))
+	assert.Equal("123,456,789,000", Comma(123456789000, ""))
 }

function/function.go

@@ -84,11 +84,9 @@ func Debounced(fn func(), duration time.Duration) func() {
 
 	go func() {
 		for {
-			select {
-			case <-timer.C:
+			<-timer.C
 			go fn()
 		}
-		}
 	}()
 
 	return func() { timer.Reset(duration) }

go.mod

@@ -1,3 +1,8 @@
 module github.com/duke-git/lancet/v2
 
 go 1.18
+
+require (
+	golang.org/x/exp v0.0.0-20221208152030-732eee02a75a
+	golang.org/x/text v0.5.0
+)

go.sum

@@ -0,0 +1,4 @@
+golang.org/x/exp v0.0.0-20221208152030-732eee02a75a h1:4iLhBPcpqFmylhnkbY3W0ONLUYYkDAW9xMFLfxgsvCw=
+golang.org/x/exp v0.0.0-20221208152030-732eee02a75a/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
+golang.org/x/text v0.5.0 h1:OLmvp0KP+FVG99Ct/qFiL/Fhk4zp4QQnZ7b2U+5piUM=
+golang.org/x/text v0.5.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=

iterator/iterator.go

@@ -10,7 +10,9 @@
 // Hope that Go can support iterator in future. see https://github.com/golang/go/discussions/54245 and https://github.com/golang/go/discussions/56413
 package iterator
 
-import "github.com/duke-git/lancet/v2/lancetconstraints"
+import (
+	"golang.org/x/exp/constraints"
+)
 
 // Iterator supports iterating over a sequence of values of type `E`.
 type Iterator[T any] interface {
@@ -142,7 +144,7 @@ func (iter *sliceIterator[T]) Set(value T) {
 
 // FromRange creates a iterator which returns the numeric range between start inclusive and end
 // exclusive by the step size. start should be less than end, step shoud be positive.
-func FromRange[T lancetconstraints.Number](start, end, step T) Iterator[T] {
+func FromRange[T constraints.Integer | constraints.Float](start, end, step T) Iterator[T] {
 	if end < start {
 		panic("RangeIterator: start should be before end")
 	} else if step <= 0 {
@@ -152,15 +154,12 @@ func FromRange[T lancetconstraints.Number](start, end, step T) Iterator[T] {
 	return &rangeIterator[T]{start: start, end: end, step: step}
 }
 
-type rangeIterator[T lancetconstraints.Number] struct {
+type rangeIterator[T constraints.Integer | constraints.Float] struct {
 	start, end, step T
 }
 
 func (iter *rangeIterator[T]) HasNext() bool {
-	if iter.start >= iter.end {
-		return false
-	}
-	return true
+	return iter.start < iter.end
 }
 
 func (iter *rangeIterator[T]) Next() (T, bool) {

lancetconstraints/constraints.go

@@ -11,13 +11,3 @@ type Comparator interface {
 	// Descending order: should return 1 -> v1 < v2, 0 -> v1 = v2, -1 -> v1 > v2
 	Compare(v1, v2 any) int
 }
-
-// Number contains all types of number and uintptr, used for generics constraint
-type Number interface {
-	~int | ~int8 | ~int16 | ~int32 | ~int64 | ~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr | ~float32 | ~float64
-}
-
-// Ordered is a constraint that permits any ordered type: any type that supports the operators < <= >= >
-type Ordered interface {
-	Number | ~string
-}

maputil/map.go

@@ -85,7 +85,7 @@ func Intersect[K comparable, V any](maps ...map[K]V) map[K]V {
 		return m
 	}
 
-	reduceMaps := make([]map[K]V, 2, 2)
+	reduceMaps := make([]map[K]V, 2)
 	result = reducer(maps[0], maps[1])
 
 	for i := 2; i < len(maps); i++ {

mathutil/mathutil.go

@@ -10,7 +10,7 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/duke-git/lancet/v2/lancetconstraints"
+	"golang.org/x/exp/constraints"
 )
 
 // Exponent calculate x^n
@@ -94,7 +94,7 @@ func TruncRound(x float64, n int) float64 {
 }
 
 // Max return max value of params
-func Max[T lancetconstraints.Number](numbers ...T) T {
+func Max[T constraints.Integer | constraints.Float](numbers ...T) T {
 	max := numbers[0]
 
 	for _, v := range numbers {
@@ -128,7 +128,7 @@ func MaxBy[T any](slice []T, comparator func(T, T) bool) T {
 }
 
 // Min return min value of params
-func Min[T lancetconstraints.Number](numbers ...T) T {
+func Min[T constraints.Integer | constraints.Float](numbers ...T) T {
 	min := numbers[0]
 
 	for _, v := range numbers {
@@ -161,8 +161,8 @@ func MinBy[T any](slice []T, comparator func(T, T) bool) T {
 	return min
 }
 
-// Average return average value of params
-func Average[T lancetconstraints.Number](numbers ...T) T {
+// Average return average value of numbers
+func Average[T constraints.Integer | constraints.Float](numbers ...T) T {
 	var sum T
 	n := T(len(numbers))
 

netutil/http_client.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"reflect"
@@ -108,7 +108,11 @@ func (client *HttpClient) SendRequest(request *HttpRequest) (*http.Response, err
 
 	client.setTLS(rawUrl)
 	client.setHeader(req, request.Headers)
-	client.setQueryParam(req, rawUrl, request.QueryParams)
+
+	err = client.setQueryParam(req, rawUrl, request.QueryParams)
+	if err != nil {
+		return nil, err
+	}
 
 	if request.FormData != nil {
 		client.setFormData(req, request.FormData)
@@ -177,7 +181,7 @@ func (client *HttpClient) setQueryParam(req *http.Request, reqUrl string, queryP
 
 func (client *HttpClient) setFormData(req *http.Request, values url.Values) {
 	formData := []byte(values.Encode())
-	req.Body = ioutil.NopCloser(bytes.NewReader(formData))
+	req.Body = io.NopCloser(bytes.NewReader(formData))
 	req.ContentLength = int64(len(formData))
 }
 

netutil/http_client_test.go

@@ -1,7 +1,7 @@
 package netutil
 
 import (
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"net/url"
@@ -32,7 +32,10 @@ func TestHttpClient_Get(t *testing.T) {
 	}
 
 	var todo Todo
-	httpClient.DecodeResponse(resp, &todo)
+	err = httpClient.DecodeResponse(resp, &todo)
+	if err != nil {
+		t.Log(err)
+	}
 
 	assert.Equal(1, todo.Id)
 }
@@ -58,7 +61,7 @@ func TestHttpClent_Post(t *testing.T) {
 		log.Fatal(err)
 	}
 
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -90,6 +93,6 @@ func TestStructToUrlValues(t *testing.T) {
 		log.Fatal(err)
 	}
 
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", string(body))
 }

netutil/http_test.go

@@ -2,8 +2,9 @@ package netutil
 
 import (
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"log"
+	"net/url"
 	"testing"
 
 	"github.com/duke-git/lancet/v2/internal"
@@ -20,7 +21,7 @@ func TestHttpGet(t *testing.T) {
 		log.Fatal(err)
 	}
 
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -40,7 +41,7 @@ func TestHttpPost(t *testing.T) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -50,23 +51,20 @@ func TestHttpPostFormData(t *testing.T) {
 		// "Content-Type": "application/x-www-form-urlencoded",
 		"Content-Type": "multipart/form-data",
 	}
-	type Todo struct {
-		UserId int    `json:"userId"`
-		Title  string `json:"title"`
-	}
-	// postData := url.Values{}
-	// postData.Add("userId", "1")
-	// postData.Add("title", "TestAddToDo")
 
-	postData := make(map[string]string)
-	postData["userId"] = "1"
-	postData["title"] = "title"
+	postData := url.Values{}
+	postData.Add("userId", "1")
+	postData.Add("title", "TestToDo")
+
+	// postData := make(map[string]string)
+	// postData["userId"] = "1"
+	// postData["title"] = "title"
 
 	resp, err := HttpPost(apiUrl, header, postData, nil)
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -87,7 +85,7 @@ func TestHttpPut(t *testing.T) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -108,7 +106,7 @@ func TestHttpPatch(t *testing.T) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 
@@ -118,7 +116,7 @@ func TestHttpDelete(t *testing.T) {
 	if err != nil {
 		log.Fatal(err)
 	}
-	body, _ := ioutil.ReadAll(resp.Body)
+	body, _ := io.ReadAll(resp.Body)
 	t.Log("response: ", resp.StatusCode, string(body))
 }
 

netutil/net.go

@@ -2,7 +2,7 @@ package netutil
 
 import (
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 	"net/url"
@@ -55,7 +55,7 @@ func GetPublicIpInfo() (*PublicIpInfo, error) {
 	}
 	defer resp.Body.Close()
 
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}

netutil/net_internal.go

@@ -3,7 +3,7 @@ package netutil
 import (
 	"bytes"
 	"errors"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/url"
 	"strings"
@@ -173,7 +173,7 @@ func setBodyByte(req *http.Request, body any) error {
 	if body != nil {
 		switch b := body.(type) {
 		case []byte:
-			req.Body = ioutil.NopCloser(bytes.NewReader(b))
+			req.Body = io.NopCloser(bytes.NewReader(b))
 			req.ContentLength = int64(len(b))
 		default:
 			return errors.New("body type should be []byte")

slice/slice.go

@@ -11,7 +11,7 @@ import (
 	"reflect"
 	"sort"
 
-	"github.com/duke-git/lancet/v2/lancetconstraints"
+	"golang.org/x/exp/constraints"
 )
 
 // Create a static variable to store the hash table.
@@ -736,7 +736,7 @@ func Shuffle[T any](slice []T) []T {
 
 // Sort sorts a slice of any ordered type(number or string), use quick sort algrithm.
 // default sort order is ascending (asc), if want descending order, set param `sortOrder` to `desc`
-func Sort[T lancetconstraints.Ordered](slice []T, sortOrder ...string) {
+func Sort[T constraints.Ordered](slice []T, sortOrder ...string) {
 	if len(sortOrder) > 0 && sortOrder[0] == "desc" {
 		quickSort(slice, 0, len(slice)-1, "desc")
 	} else {

slice/slice_internal.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"reflect"
 
-	"github.com/duke-git/lancet/v2/lancetconstraints"
+	"golang.org/x/exp/constraints"
 )
 
 // sliceValue return the reflect value of a slice
@@ -27,7 +27,7 @@ func sliceElemType(reflectType reflect.Type) reflect.Type {
 	}
 }
 
-func quickSort[T lancetconstraints.Ordered](slice []T, lowIndex, highIndex int, order string) {
+func quickSort[T constraints.Ordered](slice []T, lowIndex, highIndex int, order string) {
 	if lowIndex < highIndex {
 		p := partitionOrderedSlice(slice, lowIndex, highIndex, order)
 		quickSort(slice, lowIndex, p-1, order)
@@ -36,7 +36,7 @@ func quickSort[T lancetconstraints.Ordered](slice []T, lowIndex, highIndex int,
 }
 
 // partitionOrderedSlice split ordered slice into two parts for quick sort
-func partitionOrderedSlice[T lancetconstraints.Ordered](slice []T, lowIndex, highIndex int, order string) int {
+func partitionOrderedSlice[T constraints.Ordered](slice []T, lowIndex, highIndex int, order string) int {
 	p := slice[highIndex]
 	i := lowIndex
 

system/os.go

@@ -9,6 +9,10 @@ import (
 	"os"
 	"os/exec"
 	"runtime"
+	"unicode/utf8"
+
+	"github.com/duke-git/lancet/v2/validator"
+	"golang.org/x/text/encoding/simplifiedchinese"
 )
 
 // IsWindows check if current os is windows
@@ -50,27 +54,61 @@ func CompareOsEnv(key, comparedEnv string) bool {
 	return env == comparedEnv
 }
 
-// ExecCommand use shell /bin/bash -c to execute command
+// ExecCommand execute command, return the stdout and stderr string of command, and error if error occur
+// param `command` is a complete command string, like, ls -a (linux), dir(windows), ping 127.0.0.1
+// in linux,  use /bin/bash -c to execute command
+// in windows, use powershell.exe to execute command
 func ExecCommand(command string) (stdout, stderr string, err error) {
 	var out bytes.Buffer
-	var errout bytes.Buffer
+	var errOut bytes.Buffer
 
 	cmd := exec.Command("/bin/bash", "-c", command)
 	if IsWindows() {
-		cmd = exec.Command("cmd")
+		cmd = exec.Command("powershell.exe", command)
 	}
 	cmd.Stdout = &out
-	cmd.Stderr = &errout
+	cmd.Stderr = &errOut
+
 	err = cmd.Run()
 
 	if err != nil {
-		stderr = string(errout.Bytes())
+		if utf8.Valid(errOut.Bytes()) {
+			stderr = byteToString(errOut.Bytes(), "UTF8")
+		} else if validator.IsGBK(errOut.Bytes()) {
+			stderr = byteToString(errOut.Bytes(), "GBK")
+		}
+		return
+	}
+
+	data := out.Bytes()
+	if utf8.Valid(data) {
+		stdout = byteToString(data, "UTF8")
+	} else if validator.IsGBK(data) {
+		stdout = byteToString(data, "GBK")
 	}
-	stdout = string(out.Bytes())
 
 	return
 }
 
+func byteToString(data []byte, charset string) string {
+	var result string
+
+	switch charset {
+	case "GBK":
+		decodeBytes, _ := simplifiedchinese.GBK.NewDecoder().Bytes(data)
+		result = string(decodeBytes)
+	case "GB18030":
+		decodeBytes, _ := simplifiedchinese.GB18030.NewDecoder().Bytes(data)
+		result = string(decodeBytes)
+	case "UTF8":
+		fallthrough
+	default:
+		result = string(data)
+	}
+
+	return result
+}
+
 // GetOsBits get this system bits 32bit or 64bit
 // return bit int (32/64)
 func GetOsBits() int {

system/os_test.go

@@ -11,10 +11,10 @@ func TestOsDetection(t *testing.T) {
 	assert := internal.NewAssert(t, "TestOsJudgment")
 
 	osType, _, _ := ExecCommand("echo $OSTYPE")
-	if strings.Index(osType, "linux") != -1 {
+	if strings.Contains(osType, "linux") {
 		assert.Equal(true, IsLinux())
 	}
-	if strings.Index(osType, "darwin") != -1 {
+	if strings.Contains(osType, "darwin") {
 		assert.Equal(true, IsMac())
 	}
 }
@@ -25,7 +25,9 @@ func TestOsEnvOperation(t *testing.T) {
 	envNotExist := GetOsEnv("foo")
 	assert.Equal("", envNotExist)
 
-	SetOsEnv("foo", "foo_value")
+	err := SetOsEnv("foo", "foo_value")
+	assert.IsNil(err)
+
 	envExist := GetOsEnv("foo")
 	assert.Equal("foo_value", envExist)
 
@@ -34,7 +36,7 @@ func TestOsEnvOperation(t *testing.T) {
 	assert.Equal(false, CompareOsEnv("abc", "abc"))
 	assert.Equal(false, CompareOsEnv("abc", "abc"))
 
-	err := RemoveOsEnv("foo")
+	err = RemoveOsEnv("foo")
 	if err != nil {
 		t.Fail()
 	}
@@ -44,22 +46,27 @@ func TestOsEnvOperation(t *testing.T) {
 func TestExecCommand(t *testing.T) {
 	assert := internal.NewAssert(t, "TestExecCommand")
 
-	out, errout, err := ExecCommand("ls")
-	t.Log("std out: ", out)
-	t.Log("std err: ", errout)
+	// linux or mac
+	stdout, stderr, err := ExecCommand("ls")
+	t.Log("std out: ", stdout)
+	t.Log("std err: ", stderr)
+	assert.Equal("", stderr)
 	assert.IsNil(err)
 
-	out, errout, err = ExecCommand("abc")
-	t.Log("std out: ", out)
-	t.Log("std err: ", errout)
-	if err != nil {
-		t.Logf("error: %v\n", err)
+	// windows
+	stdout, stderr, err = ExecCommand("dir")
+	t.Log("std out: ", stdout)
+	t.Log("std err: ", stderr)
+	if IsWindows() {
+		assert.IsNil(err)
 	}
 
-	if !IsWindows() {
+	// error command
+	stdout, stderr, err = ExecCommand("abc")
+	t.Log("std out: ", stdout)
+	t.Log("std err: ", stderr)
 	assert.IsNotNil(err)
 }
-}
 
 func TestGetOsBits(t *testing.T) {
 	osBits := GetOsBits()

validator/validator.go

@@ -274,3 +274,40 @@ func IsZeroValue(value any) bool {
 
 	return reflect.DeepEqual(rv.Interface(), reflect.Zero(rv.Type()).Interface())
 }
+
+// IsGBK check if data encoding is gbk
+// Note: this function is implemented by whether double bytes fall within the encoding range of gbk,
+// while each byte of utf-8 encoding format falls within the encoding range of gbk.
+// Therefore, utf8.valid() should be called first to check whether it is not utf-8 encoding,
+// and then call IsGBK() to check gbk encoding. like below
+/**
+	data := []byte("你好")
+	if utf8.Valid(data) {
+		fmt.Println("data encoding is utf-8")
+	}else if(IsGBK(data)) {
+		fmt.Println("data encoding is GBK")
+	}
+	fmt.Println("data encoding is unknown")
+**/
+func IsGBK(data []byte) bool {
+	i := 0
+	for i < len(data) {
+		if data[i] <= 0xff {
+			i++
+			continue
+		} else {
+			if data[i] >= 0x81 &&
+				data[i] <= 0xfe &&
+				data[i+1] >= 0x40 &&
+				data[i+1] <= 0xfe &&
+				data[i+1] != 0xf7 {
+				i += 2
+				continue
+			} else {
+				return false
+			}
+		}
+	}
+
+	return true
+}

validator/validator_test.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"testing"
 	"time"
+	"unicode/utf8"
 
 	"github.com/duke-git/lancet/v2/internal"
+	"golang.org/x/text/encoding/simplifiedchinese"
 )
 
 func TestIsAllUpper(t *testing.T) {
@@ -388,3 +390,13 @@ func TestIsZeroValue(t *testing.T) {
 		assert.Equal(false, IsZeroValue(value))
 	}
 }
+
+func TestIsGBK(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsGBK")
+
+	str := "你好"
+	gbkData, _ := simplifiedchinese.GBK.NewEncoder().Bytes([]byte(str))
+
+	assert.Equal(true, IsGBK(gbkData))
+	assert.Equal(false, utf8.Valid(gbkData))
+}