test&doc: add example and update doc for function package

SECURITY.md

@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+Here is the lancet version and compatibility with go language version.
+
+| Version | Supported         |
+| ------- | ------------------|
+| 2.x.x   | +go v1.18         |
+| 1.x.x   | +go v1.12         |
+
+
+## Reporting a Vulnerability
+
+For now, there is no public website to report a vulnerability, If you find security issue in lancet, you can send it to me via my email `lanliddd.2007@163.com`.
+we can discuss it. I am appreciate if someone can create a public page for reporting vulnerability.

algorithm/lrucache.go

@@ -26,7 +26,7 @@ type LRUCache[K comparable, V any] struct {
 	length   int
 }
 
-// NewLRUCache return a LRUCache pointer
+// NewLRUCache creates a LRUCache pointer instance.
 func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V] {
 	return &LRUCache[K, V]{
 		cache:    make(map[K]*lruNode[K, V], capacity),
@@ -37,7 +37,8 @@ func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V] {
 	}
 }
 
-// Get value of key from lru cache
+// Get value of key from lru cache.
+// Play: https://go.dev/play/p/iUynEfOP8G0
 func (l *LRUCache[K, V]) Get(key K) (V, bool) {
 	var value V
 
@@ -50,7 +51,8 @@ func (l *LRUCache[K, V]) Get(key K) (V, bool) {
 	return value, false
 }
 
-// Put value of key into lru cache
+// Put value of key into lru cache.
+// Play: https://go.dev/play/p/iUynEfOP8G0
 func (l *LRUCache[K, V]) Put(key K, value V) {
 	node, ok := l.cache[key]
 	if !ok {
@@ -69,6 +71,23 @@ func (l *LRUCache[K, V]) Put(key K, value V) {
 	l.length = len(l.cache)
 }
 
+// Delete item from lru cache.
+func (l *LRUCache[K, V]) Delete(key K) bool {
+	node, ok := l.cache[key]
+	if ok {
+		key := l.deleteNode(node)
+		delete(l.cache, key)
+		return true
+	}
+
+	return false
+}
+
+// Len returns the number of items in the cache.
+func (l *LRUCache[K, V]) Len() int {
+	return l.length
+}
+
 func (l *LRUCache[K, V]) addNode(node *lruNode[K, V]) {
 	if l.tail != nil {
 		l.tail.next = node

algorithm/lrucache_example_test.go

@@ -0,0 +1,79 @@
+package algorithm
+
+import "fmt"
+
+func ExampleLRUCache_Put() {
+	cache := NewLRUCache[int, int](2)
+
+	cache.Put(1, 1)
+	cache.Put(2, 2)
+
+	result1, ok1 := cache.Get(1)
+	result2, ok2 := cache.Get(2)
+	result3, ok3 := cache.Get(3)
+
+	fmt.Println(result1, ok1)
+	fmt.Println(result2, ok2)
+	fmt.Println(result3, ok3)
+
+	// Output:
+	// 1 true
+	// 2 true
+	// 0 false
+}
+
+func ExampleLRUCache_Get() {
+	cache := NewLRUCache[int, int](2)
+
+	cache.Put(1, 1)
+	cache.Put(2, 2)
+
+	result1, ok1 := cache.Get(1)
+	result2, ok2 := cache.Get(2)
+	result3, ok3 := cache.Get(3)
+
+	fmt.Println(result1, ok1)
+	fmt.Println(result2, ok2)
+	fmt.Println(result3, ok3)
+
+	// Output:
+	// 1 true
+	// 2 true
+	// 0 false
+}
+
+func ExampleLRUCache_Delete() {
+	cache := NewLRUCache[int, int](2)
+
+	cache.Put(1, 1)
+	cache.Put(2, 2)
+
+	result1, ok1 := cache.Get(1)
+
+	ok2 := cache.Delete(2)
+
+	_, ok3 := cache.Get(2)
+
+	fmt.Println(result1, ok1)
+	fmt.Println(ok2)
+	fmt.Println(ok3)
+
+	// Output:
+	// 1 true
+	// true
+	// false
+}
+
+func ExampleLRUCache_Len() {
+	cache := NewLRUCache[int, int](2)
+
+	cache.Put(1, 1)
+	cache.Put(2, 2)
+
+	result := cache.Len()
+
+	fmt.Println(result)
+
+	// Output:
+	// 2
+}

algorithm/lrucache_test.go

@@ -9,13 +9,13 @@ import (
 func TestLRUCache(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestLRUCache")
 
-	cache := NewLRUCache[int, int](2)
+	cache := NewLRUCache[int, int](3)
 
 	cache.Put(1, 1)
 	cache.Put(2, 2)
+	cache.Put(3, 3)
 
-	_, ok := cache.Get(0)
+	asssert.Equal(3, cache.Len())
-	asssert.Equal(false, ok)
 
 	v, ok := cache.Get(1)
 	asssert.Equal(true, ok)
@@ -25,12 +25,9 @@ func TestLRUCache(t *testing.T) {
 	asssert.Equal(true, ok)
 	asssert.Equal(2, v)
 
-	cache.Put(3, 3)
+	ok = cache.Delete(2)
-	v, ok = cache.Get(1)
-	asssert.Equal(false, ok)
-	asssert.NotEqual(1, v)
-
-	v, ok = cache.Get(3)
 	asssert.Equal(true, ok)
-	asssert.Equal(3, v)
+
+	_, ok = cache.Get(2)
+	asssert.Equal(false, ok)
 }

algorithm/search.go

@@ -1,26 +1,27 @@
 // Copyright 2021 dudaodong@gmail.com. All rights reserved.
 // Use of this source code is governed by MIT license
 
-// Package algorithm contain some basic algorithm functions. eg. sort, search, list, linklist, stack, queue, tree, graph. TODO
+// Package algorithm contain some basic algorithm functions. eg. sort, search, list, linklist, stack, queue, tree, graph.
 package algorithm
 
 import "github.com/duke-git/lancet/v2/lancetconstraints"
 
 // Search algorithms see https://github.com/TheAlgorithms/Go/tree/master/search
 
-// LinearSearch Simple linear search algorithm that iterates over all elements of an slice
+// LinearSearch return the index of target in slice base on equal function.
-// If a target is found, the index of the target is returned. Else the function return -1
+// If not found return -1
-func LinearSearch[T any](slice []T, target T, comparator lancetconstraints.Comparator) int {
+func LinearSearch[T any](slice []T, target T, equal func(a, b T) bool) int {
 	for i, v := range slice {
-		if comparator.Compare(v, target) == 0 {
+		if equal(v, target) {
 			return i
 		}
 	}
 	return -1
 }
 
-// BinarySearch search for target within a sorted slice, recursive call itself.
+// BinarySearch return the index of target within a sorted slice, use binary search (recursive call itself).
-// If a target is found, the index of the target is returned. Else the function return -1
+// If not found return -1.
+// Play: https://go.dev/play/p/t6MeGiUSN47
 func BinarySearch[T any](sortedSlice []T, target T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) int {
 	if highIndex < lowIndex || len(sortedSlice) == 0 {
 		return -1
@@ -39,8 +40,9 @@ func BinarySearch[T any](sortedSlice []T, target T, lowIndex, highIndex int, com
 	return midIndex
 }
 
-// BinaryIterativeSearch search for target within a sorted slice.
+// BinaryIterativeSearch return the index of target within a sorted slice, use binary search (no recursive).
-// If a target is found, the index of the target is returned. Else the function return -1
+// If not found return -1.
+// Play: https://go.dev/play/p/Anozfr8ZLH3
 func BinaryIterativeSearch[T any](sortedSlice []T, target T, lowIndex, highIndex int, comparator lancetconstraints.Comparator) int {
 	startIndex := lowIndex
 	endIndex := highIndex

algorithm/search_example_test.go

@@ -0,0 +1,51 @@
+package algorithm
+
+import "fmt"
+
+func ExampleLinearSearch() {
+	numbers := []int{3, 4, 5, 3, 2, 1}
+
+	equalFunc := func(a, b int) bool {
+		return a == b
+	}
+
+	result1 := LinearSearch(numbers, 3, equalFunc)
+	result2 := LinearSearch(numbers, 6, equalFunc)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 0
+	// -1
+}
+
+func ExampleBinarySearch() {
+	numbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
+	comparator := &intComparator{}
+
+	result1 := BinarySearch(numbers, 5, 0, len(numbers)-1, comparator)
+	result2 := BinarySearch(numbers, 9, 0, len(numbers)-1, comparator)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 4
+	// -1
+}
+
+func ExampleBinaryIterativeSearch() {
+	numbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
+	comparator := &intComparator{}
+
+	result1 := BinaryIterativeSearch(numbers, 5, 0, len(numbers)-1, comparator)
+	result2 := BinaryIterativeSearch(numbers, 9, 0, len(numbers)-1, comparator)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 4
+	// -1
+}

algorithm/search_test.go

@@ -6,20 +6,24 @@ import (
 	"github.com/duke-git/lancet/v2/internal"
 )
 
-var sortedNumbers = []int{1, 2, 3, 4, 5, 6, 7, 8}
-
 func TestLinearSearch(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestLinearSearch")
 
-	comparator := &intComparator{}
+	numbers := []int{3, 4, 5, 3, 2, 1}
-	asssert.Equal(4, LinearSearch(sortedNumbers, 5, comparator))
+	equalFunc := func(a, b int) bool {
-	asssert.Equal(-1, LinearSearch(sortedNumbers, 9, comparator))
+		return a == b
+	}
+
+	asssert.Equal(0, LinearSearch(numbers, 3, equalFunc))
+	asssert.Equal(-1, LinearSearch(numbers, 6, equalFunc))
 }
 
 func TestBinarySearch(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestBinarySearch")
 
+	sortedNumbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
 	comparator := &intComparator{}
+
 	asssert.Equal(4, BinarySearch(sortedNumbers, 5, 0, len(sortedNumbers)-1, comparator))
 	asssert.Equal(-1, BinarySearch(sortedNumbers, 9, 0, len(sortedNumbers)-1, comparator))
 }
@@ -27,7 +31,9 @@ func TestBinarySearch(t *testing.T) {
 func TestBinaryIterativeSearch(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestBinaryIterativeSearch")
 
+	sortedNumbers := []int{1, 2, 3, 4, 5, 6, 7, 8}
 	comparator := &intComparator{}
+
 	asssert.Equal(4, BinaryIterativeSearch(sortedNumbers, 5, 0, len(sortedNumbers)-1, comparator))
 	asssert.Equal(-1, BinaryIterativeSearch(sortedNumbers, 9, 0, len(sortedNumbers)-1, comparator))
 }

algorithm/sort.go

@@ -1,12 +1,12 @@
 // Copyright 2021 dudaodong@gmail.com. All rights reserved.
 // Use of this source code is governed by MIT license
 
-// Package algorithm contain some basic algorithm functions. eg. sort, search
 package algorithm
 
 import "github.com/duke-git/lancet/v2/lancetconstraints"
 
-// BubbleSort use bubble to sort slice.
+// BubbleSort applys the bubble sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/GNdv7Jg2Taj
 func BubbleSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		for j := 0; j < len(slice)-1-i; j++ {
@@ -18,7 +18,8 @@ func BubbleSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	}
 }
 
-// InsertionSort use insertion to sort slice.
+// InsertionSort applys the insertion sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/G5LJiWgJJW6
 func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		for j := i; j > 0; j-- {
@@ -32,7 +33,8 @@ func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	}
 }
 
-// SelectionSort use selection to sort slice.
+// SelectionSort applys the selection sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/oXovbkekayS
 func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	for i := 0; i < len(slice); i++ {
 		min := i
@@ -45,7 +47,8 @@ func SelectionSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	}
 }
 
-// ShellSort shell sort slice.
+// ShellSort applys the shell sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/3ibkszpJEu3
 func ShellSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	size := len(slice)
 
@@ -64,7 +67,8 @@ func ShellSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	}
 }
 
-// QuickSort quick sorting for slice, lowIndex is 0 and highIndex is len(slice)-1
+// QuickSort quick sorting for slice, lowIndex is 0 and highIndex is len(slice)-1.
+// Play: https://go.dev/play/p/7Y7c1Elk3ax
 func QuickSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	quickSort(slice, 0, len(slice)-1, comparator)
 }
@@ -93,7 +97,8 @@ func partition[T any](slice []T, lowIndex, highIndex int, comparator lancetconst
 	return i
 }
 
-// HeapSort use heap to sort slice
+// HeapSort applys the heap sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/u6Iwa1VZS_f
 func HeapSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	size := len(slice)
 
@@ -126,7 +131,8 @@ func sift[T any](slice []T, lowIndex, highIndex int, comparator lancetconstraint
 	slice[i] = temp
 }
 
-// MergeSort merge sorting for slice
+// MergeSort applys the merge sort algorithm to sort the collection, will change the original collection data.
+// Play: https://go.dev/play/p/ydinn9YzUJn
 func MergeSort[T any](slice []T, comparator lancetconstraints.Comparator) {
 	mergeSort(slice, 0, len(slice)-1, comparator)
 }
@@ -167,7 +173,8 @@ func merge[T any](slice []T, lowIndex, midIndex, highIndex int, comparator lance
 	}
 }
 
-// CountSort use count sorting for slice
+// CountSort applys the count sort algorithm to sort the collection, don't change the original collection data.
+// Play: https://go.dev/play/p/tB-Umgm0DrP
 func CountSort[T any](slice []T, comparator lancetconstraints.Comparator) []T {
 	size := len(slice)
 	out := make([]T, size)

algorithm/sort_example_test.go

@@ -0,0 +1,93 @@
+package algorithm
+
+import "fmt"
+
+func ExampleBubbleSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	BubbleSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleCountSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	sortedNumber := CountSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	fmt.Println(sortedNumber)
+	// Output:
+	// [2 1 5 3 6 4]
+	// [1 2 3 4 5 6]
+}
+
+func ExampleHeapSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	HeapSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleMergeSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	MergeSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleInsertionSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	InsertionSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleSelectionSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	SelectionSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleShellSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	ShellSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleQuickSort() {
+	numbers := []int{2, 1, 5, 3, 6, 4}
+	comparator := &intComparator{}
+
+	QuickSort(numbers, comparator)
+
+	fmt.Println(numbers)
+	// Output:
+	// [1 2 3 4 5 6]
+}

algorithm/sort_test.go

@@ -66,6 +66,7 @@ func TestBubbleSortForStructSlice(t *testing.T) {
 
 func TestBubbleSortForIntSlice(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestBubbleSortForIntSlice")
+
 	numbers := []int{2, 1, 5, 3, 6, 4}
 	comparator := &intComparator{}
 	BubbleSort(numbers, comparator)

concurrency/channel.go

@@ -11,17 +11,18 @@ import (
 
 // Channel is a logic object which can generate or manipulate go channel
 // all methods of Channel are in the book tilted《Concurrency in Go》
-type Channel struct {
+type Channel[T any] struct {
 }
 
 // NewChannel return a Channel instance
-func NewChannel() *Channel {
+func NewChannel[T any]() *Channel[T] {
-	return &Channel{}
+	return &Channel[T]{}
 }
 
-// Generate a data of type any chan, put param `values` into the chan
+// Generate creates channel, then put values into the channel.
-func (c *Channel) Generate(ctx context.Context, values ...any) <-chan any {
+// Play:
-	dataStream := make(chan any)
+func (c *Channel[T]) Generate(ctx context.Context, values ...T) <-chan T {
+	dataStream := make(chan T)
 
 	go func() {
 		defer close(dataStream)
@@ -38,9 +39,10 @@ func (c *Channel) Generate(ctx context.Context, values ...any) <-chan any {
 	return dataStream
 }
 
-// Repeat return a data of type any chan, put param `values` into the chan repeatly until cancel the context.
+// Repeat create channel, put values into the channel repeatly until cancel the context.
-func (c *Channel) Repeat(ctx context.Context, values ...any) <-chan any {
+// Play:
-	dataStream := make(chan any)
+func (c *Channel[T]) Repeat(ctx context.Context, values ...T) <-chan T {
+	dataStream := make(chan T)
 
 	go func() {
 		defer close(dataStream)
@@ -57,10 +59,11 @@ func (c *Channel) Repeat(ctx context.Context, values ...any) <-chan any {
 	return dataStream
 }
 
-// RepeatFn return a chan, excutes fn repeatly, and put the result into retruned chan
+// RepeatFn create a channel, excutes fn repeatly, and put the result into the channel
-// until close the `done` channel
+// until close context.
-func (c *Channel) RepeatFn(ctx context.Context, fn func() any) <-chan any {
+// Play:
-	dataStream := make(chan any)
+func (c *Channel[T]) RepeatFn(ctx context.Context, fn func() T) <-chan T {
+	dataStream := make(chan T)
 
 	go func() {
 		defer close(dataStream)
@@ -75,9 +78,10 @@ func (c *Channel) RepeatFn(ctx context.Context, fn func() any) <-chan any {
 	return dataStream
 }
 
-// Take return a chan whose values are tahken from another chan
+// Take create a channel whose values are taken from another channel with limit number.
-func (c *Channel) Take(ctx context.Context, valueStream <-chan any, number int) <-chan any {
+// Play:
-	takeStream := make(chan any)
+func (c *Channel[T]) Take(ctx context.Context, valueStream <-chan T, number int) <-chan T {
+	takeStream := make(chan T)
 
 	go func() {
 		defer close(takeStream)
@@ -94,16 +98,17 @@ func (c *Channel) Take(ctx context.Context, valueStream <-chan any, number int)
 	return takeStream
 }
 
-// FanIn merge multiple channels into one channel
+// FanIn merge multiple channels into one channel.
-func (c *Channel) FanIn(ctx context.Context, channels ...<-chan any) <-chan any {
+// Play:
-	out := make(chan any)
+func (c *Channel[T]) FanIn(ctx context.Context, channels ...<-chan T) <-chan T {
+	out := make(chan T)
 
 	go func() {
 		var wg sync.WaitGroup
 		wg.Add(len(channels))
 
 		for _, c := range channels {
-			go func(c <-chan any) {
+			go func(c <-chan T) {
 				defer wg.Done()
 				for v := range c {
 					select {
@@ -121,10 +126,11 @@ func (c *Channel) FanIn(ctx context.Context, channels ...<-chan any) <-chan any
 	return out
 }
 
-// Tee split one chanel into two channels
+// Tee split one chanel into two channels, until cancel the context.
-func (c *Channel) Tee(ctx context.Context, in <-chan any) (<-chan any, <-chan any) {
+// Play:
-	out1 := make(chan any)
+func (c *Channel[T]) Tee(ctx context.Context, in <-chan T) (<-chan T, <-chan T) {
-	out2 := make(chan any)
+	out1 := make(chan T)
+	out2 := make(chan T)
 
 	go func() {
 		defer close(out1)
@@ -147,18 +153,19 @@ func (c *Channel) Tee(ctx context.Context, in <-chan any) (<-chan any, <-chan an
 	return out1, out2
 }
 
-// Bridge link multiply channels into one channel
+// Bridge link multiply channels into one channel.
-func (c *Channel) Bridge(ctx context.Context, chanStream <-chan <-chan any) <-chan any {
+// Play:
-	valStream := make(chan any)
+func (c *Channel[T]) Bridge(ctx context.Context, chanStream <-chan <-chan T) <-chan T {
+	valStream := make(chan T)
 
 	go func() {
 		defer close(valStream)
 
 		for {
-			var stream <-chan any
+			var stream <-chan T
 			select {
 			case maybeStream, ok := <-chanStream:
-				if ok == false {
+				if !ok {
 					return
 				}
 				stream = maybeStream
@@ -178,8 +185,9 @@ func (c *Channel) Bridge(ctx context.Context, chanStream <-chan <-chan any) <-ch
 	return valStream
 }
 
-// Or read one or more channels into one channel, will close when any readin channel is closed
+// Or read one or more channels into one channel, will close when any readin channel is closed.
-func (c *Channel) Or(channels ...<-chan any) <-chan any {
+// Play:
+func (c *Channel[T]) Or(channels ...<-chan T) <-chan T {
 	switch len(channels) {
 	case 0:
 		return nil
@@ -187,7 +195,7 @@ func (c *Channel) Or(channels ...<-chan any) <-chan any {
 		return channels[0]
 	}
 
-	orDone := make(chan any)
+	orDone := make(chan T)
 
 	go func() {
 		defer close(orDone)
@@ -199,17 +207,12 @@ func (c *Channel) Or(channels ...<-chan any) <-chan any {
 			case <-channels[1]:
 			}
 		default:
-			m := len(channels) / 2
 			select {
-			case <-c.Or(channels[:m]...):
+			case <-channels[0]:
-			case <-c.Or(channels[m:]...):
+			case <-channels[1]:
+			case <-channels[2]:
+			case <-c.Or(append(channels[3:], orDone)...):
 			}
-			// select {
-			// case <-channels[0]:
-			// case <-channels[1]:
-			// case <-channels[2]:
-			// case <-c.Or(append(channels[3:], orDone)...):
-			// }
 		}
 	}()
 
@@ -217,8 +220,9 @@ func (c *Channel) Or(channels ...<-chan any) <-chan any {
 }
 
 // OrDone read a channel into another channel, will close until cancel context.
-func (c *Channel) OrDone(ctx context.Context, channel <-chan any) <-chan any {
+// Play:
-	valStream := make(chan any)
+func (c *Channel[T]) OrDone(ctx context.Context, channel <-chan T) <-chan T {
+	valStream := make(chan T)
 
 	go func() {
 		defer close(valStream)

concurrency/channel_example_test.go

@@ -0,0 +1,196 @@
+package concurrency
+
+import (
+	"context"
+	"fmt"
+	"time"
+)
+
+func ExampleChannel_Generate() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	intStream := c.Generate(ctx, 1, 2, 3)
+
+	fmt.Println(<-intStream)
+	fmt.Println(<-intStream)
+	fmt.Println(<-intStream)
+
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+
+func ExampleChannel_Repeat() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 4)
+
+	for v := range intStream {
+		fmt.Println(v)
+	}
+	// Output:
+	// 1
+	// 2
+	// 1
+	// 2
+}
+
+func ExampleChannel_RepeatFn() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	fn := func() string {
+		return "hello"
+	}
+
+	c := NewChannel[string]()
+	intStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
+
+	for v := range intStream {
+		fmt.Println(v)
+	}
+	// Output:
+	// hello
+	// hello
+	// hello
+}
+
+func ExampleChannel_Take() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	numbers := make(chan int, 5)
+	numbers <- 1
+	numbers <- 2
+	numbers <- 3
+	numbers <- 4
+	numbers <- 5
+	defer close(numbers)
+
+	c := NewChannel[int]()
+	intStream := c.Take(ctx, numbers, 3)
+
+	for v := range intStream {
+		fmt.Println(v)
+	}
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+
+func ExampleChannel_FanIn() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	channels := make([]<-chan int, 2)
+
+	for i := 0; i < 2; i++ {
+		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 2)
+	}
+
+	chs := c.FanIn(ctx, channels...)
+
+	for v := range chs {
+		fmt.Println(v) //1 1 0 0 or 0 0 1 1
+	}
+
+}
+
+func ExampleChannel_Or() {
+	sig := func(after time.Duration) <-chan any {
+		c := make(chan any)
+		go func() {
+			defer close(c)
+			time.Sleep(after)
+		}()
+		return c
+	}
+
+	start := time.Now()
+
+	c := NewChannel[any]()
+	<-c.Or(
+		sig(1*time.Second),
+		sig(2*time.Second),
+		sig(3*time.Second),
+	)
+
+	if time.Since(start).Seconds() < 2 {
+		fmt.Println("ok")
+	}
+	// Output:
+	// ok
+}
+
+func ExampleChannel_OrDone() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	intStream := c.Take(ctx, c.Repeat(ctx, 1), 3)
+
+	for v := range c.OrDone(ctx, intStream) {
+		fmt.Println(v)
+	}
+	// Output:
+	// 1
+	// 1
+	// 1
+}
+
+func ExampleChannel_Tee() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	intStream := c.Take(ctx, c.Repeat(ctx, 1), 2)
+
+	ch1, ch2 := c.Tee(ctx, intStream)
+
+	for v := range ch1 {
+		fmt.Println(v)
+		fmt.Println(<-ch2)
+	}
+	// Output:
+	// 1
+	// 1
+	// 1
+	// 1
+}
+
+func ExampleChannel_Bridge() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := NewChannel[int]()
+	genVals := func() <-chan <-chan int {
+		out := make(chan (<-chan int))
+		go func() {
+			defer close(out)
+			for i := 1; i <= 5; i++ {
+				stream := make(chan int, 1)
+				stream <- i
+				close(stream)
+				out <- stream
+			}
+		}()
+		return out
+	}
+
+	for v := range c.Bridge(ctx, genVals()) {
+		fmt.Println(v)
+	}
+	// Output:
+	// 1
+	// 2
+	// 3
+	// 4
+	// 5
+}

concurrency/channel_test.go

@@ -14,12 +14,9 @@ func TestGenerate(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
 	intStream := c.Generate(ctx, 1, 2, 3)
 
-	// for v := range intStream {
-	// 	t.Log(v) //1, 2, 3
-	// }
 	assert.Equal(1, <-intStream)
 	assert.Equal(2, <-intStream)
 	assert.Equal(3, <-intStream)
@@ -31,12 +28,9 @@ func TestRepeat(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
 	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 5)
 
-	// for v := range intStream {
-	// 	t.Log(v) //1, 2, 1, 2, 1
-	// }
 	assert.Equal(1, <-intStream)
 	assert.Equal(2, <-intStream)
 	assert.Equal(1, <-intStream)
@@ -50,17 +44,13 @@ func TestRepeatFn(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	fn := func() any {
+	fn := func() string {
 		s := "a"
 		return s
 	}
-	c := NewChannel()
+	c := NewChannel[string]()
 	dataStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
 
-	// for v := range dataStream {
-	// 	t.Log(v) //a, a, a
-	// }
-
 	assert.Equal("a", <-dataStream)
 	assert.Equal("a", <-dataStream)
 	assert.Equal("a", <-dataStream)
@@ -72,7 +62,7 @@ func TestTake(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	numbers := make(chan any, 5)
+	numbers := make(chan int, 5)
 	numbers <- 1
 	numbers <- 2
 	numbers <- 3
@@ -80,7 +70,7 @@ func TestTake(t *testing.T) {
 	numbers <- 5
 	defer close(numbers)
 
-	c := NewChannel()
+	c := NewChannel[int]()
 	intStream := c.Take(ctx, numbers, 3)
 
 	assert.Equal(1, <-intStream)
@@ -94,8 +84,8 @@ func TestFanIn(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
-	channels := make([]<-chan any, 3)
+	channels := make([]<-chan int, 3)
 
 	for i := 0; i < 3; i++ {
 		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 3)
@@ -124,7 +114,7 @@ func TestOr(t *testing.T) {
 
 	start := time.Now()
 
-	c := NewChannel()
+	c := NewChannel[any]()
 	<-c.Or(
 		sig(1*time.Second),
 		sig(2*time.Second),
@@ -133,9 +123,7 @@ func TestOr(t *testing.T) {
 		sig(5*time.Second),
 	)
 
-	t.Logf("done after %v", time.Since(start))
+	assert.Equal(true, time.Since(start).Seconds() < 2)
-
-	assert.Equal(1, 1)
 }
 
 func TestOrDone(t *testing.T) {
@@ -144,16 +132,12 @@ func TestOrDone(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
 	intStream := c.Take(ctx, c.Repeat(ctx, 1), 3)
 
-	var res any
 	for val := range c.OrDone(ctx, intStream) {
-		t.Logf("%v", val)
+		assert.Equal(1, val)
-		res = val
 	}
-
-	assert.Equal(1, res)
 }
 
 func TestTee(t *testing.T) {
@@ -162,15 +146,13 @@ func TestTee(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
 	inStream := c.Take(ctx, c.Repeat(ctx, 1), 4)
 
 	out1, out2 := c.Tee(ctx, inStream)
 	for val := range out1 {
 		val1 := val
 		val2 := <-out2
-		// t.Log("val1 is", val1)
-		// t.Log("val2 is", val2)
 		assert.Equal(1, val1)
 		assert.Equal(1, val2)
 	}
@@ -182,13 +164,13 @@ func TestBridge(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := NewChannel()
+	c := NewChannel[int]()
-	genVals := func() <-chan <-chan any {
+	genVals := func() <-chan <-chan int {
-		chanStream := make(chan (<-chan any))
+		chanStream := make(chan (<-chan int))
 		go func() {
 			defer close(chanStream)
 			for i := 0; i < 10; i++ {
-				stream := make(chan any, 1)
+				stream := make(chan int, 1)
 				stream <- i
 				close(stream)
 				chanStream <- stream

condition/condition.go

@@ -13,6 +13,7 @@ import "reflect"
 // If the type has an IsZero() bool method, the opposite value is returned.
 // Slices and maps are truthy if they have a length greater than zero.
 // All other types are truthy if they are not their zero value.
+// Play: https://go.dev/play/p/ETzeDJRSvhm
 func Bool[T any](value T) bool {
 	switch m := any(value).(type) {
 	case interface{ Bool() bool }:
@@ -34,40 +35,47 @@ func reflectValue(vp any) bool {
 }
 
 // And returns true if both a and b are truthy.
+// Play: https://go.dev/play/p/W1SSUmt6pvr
 func And[T, U any](a T, b U) bool {
 	return Bool(a) && Bool(b)
 }
 
-// Or returns false iff neither a nor b is truthy.
+// Or returns false if neither a nor b is truthy.
+// Play: https://go.dev/play/p/UlQTxHaeEkq
 func Or[T, U any](a T, b U) bool {
 	return Bool(a) || Bool(b)
 }
 
-// Xor returns true iff a or b but not both is truthy.
+// Xor returns true if a or b but not both is truthy.
+// Play: https://go.dev/play/p/gObZrW7ZbG8
 func Xor[T, U any](a T, b U) bool {
 	valA := Bool(a)
 	valB := Bool(b)
 	return (valA || valB) && valA != valB
 }
 
-// Nor returns true iff neither a nor b is truthy.
+// Nor returns true if neither a nor b is truthy.
+// Play: https://go.dev/play/p/g2j08F_zZky
 func Nor[T, U any](a T, b U) bool {
 	return !(Bool(a) || Bool(b))
 }
 
-// Xnor returns true iff both a and b or neither a nor b are truthy.
+// Xnor returns true if both a and b or neither a nor b are truthy.
+// Play: https://go.dev/play/p/OuDB9g51643
 func Xnor[T, U any](a T, b U) bool {
 	valA := Bool(a)
 	valB := Bool(b)
 	return (valA && valB) || (!valA && !valB)
 }
 
-// Nand returns false iff both a and b are truthy.
+// Nand returns false if both a and b are truthy.
+// Play: https://go.dev/play/p/vSRMLxLIbq8
 func Nand[T, U any](a T, b U) bool {
 	return !Bool(a) || !Bool(b)
 }
 
-// TernaryOperator checks the value of param `isTrue`, if true return ifValue else return elseValue
+// TernaryOperator checks the value of param `isTrue`, if true return ifValue else return elseValue.
+// Play: https://go.dev/play/p/ElllPZY0guT
 func TernaryOperator[T, U any](isTrue T, ifValue U, elseValue U) U {
 	if Bool(isTrue) {
 		return ifValue

condition/condition_example_test.go

@@ -0,0 +1,163 @@
+package condition
+
+import "fmt"
+
+func ExampleBool() {
+	// bool
+	result1 := Bool(false)
+	result2 := Bool(true)
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// integer
+	result3 := Bool(0)
+	result4 := Bool(1)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// string
+	result5 := Bool("")
+	result6 := Bool(" ")
+	fmt.Println(result5)
+	fmt.Println(result6)
+
+	// slice
+	var nums = []int{}
+	result7 := Bool(nums)
+	nums = append(nums, 1, 2)
+	result8 := Bool(nums)
+	fmt.Println(result7)
+	fmt.Println(result8)
+
+	// Output:
+	// false
+	// true
+	// false
+	// true
+	// false
+	// true
+	// false
+	// true
+}
+
+func ExampleAnd() {
+	result1 := And(0, 1)
+	result2 := And(0, "")
+	result3 := And(0, "0")
+	result4 := And(1, "0")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// false
+	// true
+}
+
+func ExampleOr() {
+	result1 := Or(0, "")
+	result2 := Or(0, 1)
+	result3 := Or(0, "0")
+	result4 := Or(1, "0")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// true
+	// true
+	// true
+}
+
+func ExampleXor() {
+	result1 := Xor(0, 0)
+	result2 := Xor(1, 1)
+	result3 := Xor(0, 1)
+	result4 := Xor(1, 0)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// true
+	// true
+}
+
+func ExampleNor() {
+	result1 := Nor(0, 0)
+	result2 := Nor(1, 1)
+	result3 := Nor(0, 1)
+	result4 := Nor(1, 0)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// false
+	// false
+	// false
+}
+
+func ExampleXnor() {
+	result1 := Xnor(0, 0)
+	result2 := Xnor(1, 1)
+	result3 := Xnor(0, 1)
+	result4 := Xnor(1, 0)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// true
+	// false
+	// false
+}
+
+func ExampleNand() {
+	result1 := Nand(0, 0)
+	result2 := Nand(1, 0)
+	result3 := Nand(0, 1)
+	result4 := Nand(1, 1)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// true
+	// true
+	// false
+}
+
+func ExampleTernaryOperator() {
+	conditionTrue := 2 > 1
+	result1 := TernaryOperator(conditionTrue, 0, 1)
+	fmt.Println(result1)
+
+	conditionFalse := 2 > 3
+	result2 := TernaryOperator(conditionFalse, 0, 1)
+	fmt.Println(result2)
+
+	// Output:
+	// 0
+	// 1
+}

convertor/convertor.go

@@ -17,12 +17,14 @@ import (
 	"strings"
 )
 
-// ToBool convert string to a boolean
+// ToBool convert string to boolean.
+// Play: https://go.dev/play/p/ARht2WnGdIN
 func ToBool(s string) (bool, error) {
 	return strconv.ParseBool(s)
 }
 
-// ToBytes convert interface to bytes
+// ToBytes convert value to byte slice.
+// Play: https://go.dev/play/p/fAMXYFDvOvr
 func ToBytes(value any) ([]byte, error) {
 	v := reflect.ValueOf(value)
 
@@ -63,7 +65,8 @@ func ToBytes(value any) ([]byte, error) {
 	}
 }
 
-// ToChar convert string to char slice
+// ToChar convert string to char slice.
+// Play: https://go.dev/play/p/JJ1SvbFkVdM
 func ToChar(s string) []string {
 	c := make([]string, 0)
 	if len(s) == 0 {
@@ -75,7 +78,8 @@ func ToChar(s string) []string {
 	return c
 }
 
-// ToChannel convert a array of elements to a read-only channels
+// ToChannel convert a slice of elements to a read-only channel.
+// Play: https://go.dev/play/p/hOx_oYZbAnL
 func ToChannel[T any](array []T) <-chan T {
 	ch := make(chan T)
 
@@ -90,38 +94,59 @@ func ToChannel[T any](array []T) <-chan T {
 }
 
 // ToString convert value to string
+// for number, string, []byte, will convert to string
+// for other type (slice, map, array, struct) will call json.Marshal.
+// Play: https://go.dev/play/p/nF1zOOslpQq
 func ToString(value any) string {
-	result := ""
 	if value == nil {
-		return result
+		return ""
 	}
 
-	v := reflect.ValueOf(value)
+	switch val := value.(type) {
-
+	case float32:
-	switch value.(type) {
+		return strconv.FormatFloat(float64(val), 'f', -1, 32)
-	case float32, float64:
+	case float64:
-		result = strconv.FormatFloat(v.Float(), 'f', -1, 64)
+		return strconv.FormatFloat(val, 'f', -1, 64)
-		return result
+	case int:
-	case int, int8, int16, int32, int64:
+		return strconv.FormatInt(int64(val), 10)
-		result = strconv.FormatInt(v.Int(), 10)
+	case int8:
-		return result
+		return strconv.FormatInt(int64(val), 10)
-	case uint, uint8, uint16, uint32, uint64:
+	case int16:
-		result = strconv.FormatUint(v.Uint(), 10)
+		return strconv.FormatInt(int64(val), 10)
-		return result
+	case int32:
+		return strconv.FormatInt(int64(val), 10)
+	case int64:
+		return strconv.FormatInt(val, 10)
+	case uint:
+		return strconv.FormatUint(uint64(val), 10)
+	case uint8:
+		return strconv.FormatUint(uint64(val), 10)
+	case uint16:
+		return strconv.FormatUint(uint64(val), 10)
+	case uint32:
+		return strconv.FormatUint(uint64(val), 10)
+	case uint64:
+		return strconv.FormatUint(val, 10)
 	case string:
-		result = v.String()
+		return val
-		return result
 	case []byte:
-		result = string(v.Bytes())
+		return string(val)
-		return result
 	default:
-		newValue, _ := json.Marshal(value)
+		b, err := json.Marshal(val)
-		result = string(newValue)
+		if err != nil {
-		return result
+			return ""
+		}
+		return string(b)
+
+		// todo: maybe we should't supprt other type conversion
+		// v := reflect.ValueOf(value)
+		// log.Panicf("Unsupported data type: %s ", v.String())
+		// return ""
 	}
 }
 
-// ToJson convert value to a valid json string
+// ToJson convert value to a json string.
+// Play: https://go.dev/play/p/2rLIkMmXWvR
 func ToJson(value any) (string, error) {
 	result, err := json.Marshal(value)
 	if err != nil {
@@ -131,7 +156,8 @@ func ToJson(value any) (string, error) {
 	return string(result), nil
 }
 
-// ToFloat convert value to a float64, if input is not a float return 0.0 and error
+// ToFloat convert value to float64, if input is not a float return 0.0 and error.
+// Play: https://go.dev/play/p/4YTmPCibqHJ
 func ToFloat(value any) (float64, error) {
 	v := reflect.ValueOf(value)
 
@@ -158,12 +184,13 @@ func ToFloat(value any) (float64, error) {
 	}
 }
 
-// ToInt convert value to a int64, if input is not a numeric format return 0 and error
+// ToInt convert value to int64 value, if input is not numerical, return 0 and error.
+// Play: https://go.dev/play/p/9_h9vIt-QZ_b
 func ToInt(value any) (int64, error) {
 	v := reflect.ValueOf(value)
 
 	var result int64
-	err := fmt.Errorf("ToInt: invalid interface type %T", value)
+	err := fmt.Errorf("ToInt: invalid value type %T", value)
 	switch value.(type) {
 	case int, int8, int16, int32, int64:
 		result = v.Int()
@@ -185,12 +212,14 @@ func ToInt(value any) (int64, error) {
 	}
 }
 
-// ToPointer returns a pointer to this value
+// ToPointer returns a pointer to passed value.
+// Play: https://go.dev/play/p/ASf_etHNlw1
 func ToPointer[T any](value T) *T {
 	return &value
 }
 
-// ToMap convert a slice or an array of structs to a map based on iteratee function
+// ToMap convert a slice of structs to a map based on iteratee function.
+// Play: https://go.dev/play/p/tVFy7E-t24l
 func ToMap[T any, K comparable, V any](array []T, iteratee func(T) (K, V)) map[K]V {
 	result := make(map[K]V, len(array))
 	for _, item := range array {
@@ -202,7 +231,8 @@ func ToMap[T any, K comparable, V any](array []T, iteratee func(T) (K, V)) map[K
 }
 
 // StructToMap convert struct to map, only convert exported struct field
-// map key is specified same as struct field tag `json` value
+// map key is specified same as struct field tag `json` value.
+// Play: https://go.dev/play/p/KYGYJqNUBOI
 func StructToMap(value any) (map[string]any, error) {
 	v := reflect.ValueOf(value)
 	t := reflect.TypeOf(value)
@@ -231,7 +261,8 @@ func StructToMap(value any) (map[string]any, error) {
 	return result, nil
 }
 
-// MapToSlice convert a map to a slice based on iteratee function
+// MapToSlice convert map to slice based on iteratee function.
+// Play: https://go.dev/play/p/dmX4Ix5V6Wl
 func MapToSlice[T any, K comparable, V any](aMap map[K]V, iteratee func(K, V) T) []T {
 	result := make([]T, 0, len(aMap))
 
@@ -242,7 +273,8 @@ func MapToSlice[T any, K comparable, V any](aMap map[K]V, iteratee func(K, V) T)
 	return result
 }
 
-// ColorHexToRGB convert hex color to rgb color
+// ColorHexToRGB convert hex color to rgb color.
+// Play: https://go.dev/play/p/o7_ft-JCJBV
 func ColorHexToRGB(colorHex string) (red, green, blue int) {
 	colorHex = strings.TrimPrefix(colorHex, "#")
 	color64, err := strconv.ParseInt(colorHex, 16, 32)
@@ -253,7 +285,8 @@ func ColorHexToRGB(colorHex string) (red, green, blue int) {
 	return color >> 16, (color & 0x00FF00) >> 8, color & 0x0000FF
 }
 
-// ColorRGBToHex convert rgb color to hex color
+// ColorRGBToHex convert rgb color to hex color.
+// Play: https://go.dev/play/p/nzKS2Ro87J1
 func ColorRGBToHex(red, green, blue int) string {
 	r := strconv.FormatInt(int64(red), 16)
 	g := strconv.FormatInt(int64(green), 16)
@@ -272,7 +305,8 @@ func ColorRGBToHex(red, green, blue int) string {
 	return "#" + r + g + b
 }
 
-// EncodeByte encode data to byte
+// EncodeByte encode data to byte slice.
+// Play: https://go.dev/play/p/DVmM1G5JfuP
 func EncodeByte(data any) ([]byte, error) {
 	buffer := bytes.NewBuffer(nil)
 	encoder := gob.NewEncoder(buffer)
@@ -283,7 +317,8 @@ func EncodeByte(data any) ([]byte, error) {
 	return buffer.Bytes(), nil
 }
 
-// DecodeByte decode byte data to target object
+// DecodeByte decode byte slice data to target object.
+// Play: https://go.dev/play/p/zI6xsmuQRbn
 func DecodeByte(data []byte, target any) error {
 	buffer := bytes.NewBuffer(data)
 	decoder := gob.NewDecoder(buffer)

convertor/convertor_example_test.go

@@ -0,0 +1,254 @@
+package convertor
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func ExampleToBool() {
+	cases := []string{"1", "true", "True", "false", "False", "0", "123", "0.0", "abc"}
+
+	for i := 0; i < len(cases); i++ {
+		result, _ := ToBool(cases[i])
+		fmt.Println(result)
+	}
+
+	// Output:
+	// true
+	// true
+	// true
+	// false
+	// false
+	// false
+	// false
+	// false
+	// false
+}
+
+func ExampleToBytes() {
+	result1, _ := ToBytes(1)
+	result2, _ := ToBytes("abc")
+	result3, _ := ToBytes(true)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [0 0 0 0 0 0 0 1]
+	// [97 98 99]
+	// [116 114 117 101]
+}
+
+func ExampleToChar() {
+	result1 := ToChar("")
+	result2 := ToChar("abc")
+	result3 := ToChar("1 2#3")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// []
+	// [a b c]
+	// [1   2 # 3]
+}
+
+func ExampleToChannel() {
+	ch := ToChannel([]int{1, 2, 3})
+	result1 := <-ch
+	result2 := <-ch
+	result3 := <-ch
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+
+func ExampleToString() {
+	result1 := ToString("")
+	result2 := ToString(nil)
+	result3 := ToString(0)
+	result4 := ToString(1.23)
+	result5 := ToString(true)
+	result6 := ToString(false)
+	result7 := ToString([]int{1, 2, 3})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+	fmt.Println(result6)
+	fmt.Println(result7)
+
+	// Output:
+	//
+	//
+	// 0
+	// 1.23
+	// true
+	// false
+	// [1,2,3]
+}
+
+func ExampleToJson() {
+
+	aMap := map[string]int{"a": 1, "b": 2, "c": 3}
+	result1, err := ToJson(aMap)
+	if err != nil {
+		fmt.Printf("%v", err)
+	}
+	fmt.Println(result1)
+
+	// Output:
+	// {"a":1,"b":2,"c":3}
+}
+
+func ExampleToFloat() {
+	result1, _ := ToFloat("")
+	result2, _ := ToFloat("abc")
+	result3, _ := ToFloat("-1")
+	result4, _ := ToFloat("-.11")
+	result5, _ := ToFloat("1.23e3")
+	result6, _ := ToFloat(true)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+	fmt.Println(result6)
+
+	// Output:
+	// 0
+	// 0
+	// -1
+	// -0.11
+	// 1230
+	// 0
+}
+
+func ExampleToInt() {
+	result1, _ := ToInt("123")
+	result2, _ := ToInt("-123")
+	result3, _ := ToInt(float64(12.3))
+	result4, _ := ToInt("abc")
+	result5, _ := ToInt(true)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+
+	// Output:
+	// 123
+	// -123
+	// 12
+	// 0
+	// 0
+}
+
+func ExampleToPointer() {
+	result := ToPointer(123)
+	fmt.Println(*result)
+
+	// Output:
+	// 123
+}
+
+func ExampleToMap() {
+	type Message struct {
+		name string
+		code int
+	}
+	messages := []Message{
+		{name: "Hello", code: 100},
+		{name: "Hi", code: 101},
+	}
+	result := ToMap(messages, func(msg Message) (int, string) {
+		return msg.code, msg.name
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[100:Hello 101:Hi]
+}
+
+func ExampleStructToMap() {
+	type People struct {
+		Name string `json:"name"`
+		age  int
+	}
+	p := People{
+		"test",
+		100,
+	}
+	pm, _ := StructToMap(p)
+
+	fmt.Println(pm)
+
+	// Output:
+	// map[name:test]
+}
+
+func ExampleMapToSlice() {
+	aMap := map[string]int{"a": 1, "b": 2, "c": 3}
+	result := MapToSlice(aMap, func(key string, value int) string {
+		return key + ":" + strconv.Itoa(value)
+	})
+
+	fmt.Println(result) //[]string{"a:1", "c:3", "b:2"} (random order)
+}
+
+func ExampleColorHexToRGB() {
+	colorHex := "#003366"
+	r, g, b := ColorHexToRGB(colorHex)
+
+	fmt.Println(r, g, b)
+
+	// Output:
+	// 0 51 102
+}
+
+func ExampleColorRGBToHex() {
+	r := 0
+	g := 51
+	b := 102
+	colorHex := ColorRGBToHex(r, g, b)
+
+	fmt.Println(colorHex)
+
+	// Output:
+	// #003366
+}
+
+func ExampleEncodeByte() {
+	byteData, _ := EncodeByte("abc")
+	fmt.Println(byteData)
+
+	// Output:
+	// [6 12 0 3 97 98 99]
+}
+
+func ExampleDecodeByte() {
+	var obj string
+	byteData := []byte{6, 12, 0, 3, 97, 98, 99}
+	err := DecodeByte(byteData, &obj)
+	if err != nil {
+		return
+	}
+
+	fmt.Println(obj)
+
+	// Output:
+	// abc
+}

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, <-ch)
-	assert.Equal(1, val1)
+	assert.Equal(2, <-ch)
-
+	assert.Equal(3, <-ch)
-	val2, _ := <-ch
-	assert.Equal(2, val2)
-
-	val3, _ := <-ch
-	assert.Equal(3, val3)
 
 	_, ok := <-ch
 	assert.Equal(false, ok)
@@ -137,9 +132,10 @@ func TestToString(t *testing.T) {
 		"", "",
 		"0", "1", "-1",
 		"123", "123", "123", "123", "123", "123", "123",
-		"12.3", "12.300000190734863",
+		"12.3", "12.3",
 		"true", "false",
-		"[1,2,3]", "{\"a\":1,\"b\":2,\"c\":3}", "{\"Name\":\"TestStruct\"}", "hello"}
+		"[1,2,3]", "{\"a\":1,\"b\":2,\"c\":3}", "{\"Name\":\"TestStruct\"}", "hello",
+	}
 
 	for i := 0; i < len(cases); i++ {
 		actual := ToString(cases[i])
@@ -253,6 +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/aes.go

@@ -17,15 +17,19 @@ import (
 // AesEcbEncrypt encrypt data with key use AES ECB algorithm
 // len(key) should be 16, 24 or 32
 func AesEcbEncrypt(data, key []byte) []byte {
-	cipher, _ := aes.NewCipher(generateAesKey(key))
 	length := (len(data) + aes.BlockSize) / aes.BlockSize
 	plain := make([]byte, length*aes.BlockSize)
+
 	copy(plain, data)
+
 	pad := byte(len(plain) - len(data))
 	for i := len(data); i < len(plain); i++ {
 		plain[i] = pad
 	}
+
 	encrypted := make([]byte, len(plain))
+	cipher, _ := aes.NewCipher(generateAesKey(key))
+
 	for bs, be := 0, cipher.BlockSize(); bs <= len(data); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {
 		cipher.Encrypt(encrypted[bs:be], plain[bs:be])
 	}
@@ -108,27 +112,32 @@ func AesCfbEncrypt(data, key []byte) []byte {
 
 	encrypted := make([]byte, aes.BlockSize+len(data))
 	iv := encrypted[:aes.BlockSize]
+
 	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
 		panic(err)
 	}
 
 	stream := cipher.NewCFBEncrypter(block, iv)
 	stream.XORKeyStream(encrypted[aes.BlockSize:], data)
+
 	return encrypted
 }
 
 // AesCfbDecrypt decrypt data with key use AES CFB algorithm
 // len(encrypted) should be great than 16, len(key) should be 16, 24 or 32
 func AesCfbDecrypt(encrypted, key []byte) []byte {
-	block, _ := aes.NewCipher(key)
 	if len(encrypted) < aes.BlockSize {
 		panic("encrypted data is too short")
 	}
+
+	block, _ := aes.NewCipher(key)
 	iv := encrypted[:aes.BlockSize]
 	encrypted = encrypted[aes.BlockSize:]
 
 	stream := cipher.NewCFBDecrypter(block, iv)
+
 	stream.XORKeyStream(encrypted, encrypted)
+
 	return encrypted
 }
 
@@ -139,6 +148,7 @@ func AesOfbEncrypt(data, key []byte) []byte {
 	if err != nil {
 		panic(err)
 	}
+
 	data = pkcs7Padding(data, aes.BlockSize)
 	encrypted := make([]byte, aes.BlockSize+len(data))
 	iv := encrypted[:aes.BlockSize]
@@ -148,6 +158,7 @@ func AesOfbEncrypt(data, key []byte) []byte {
 
 	stream := cipher.NewOFB(block, iv)
 	stream.XORKeyStream(encrypted[aes.BlockSize:], data)
+
 	return encrypted
 }
 
@@ -170,5 +181,6 @@ func AesOfbDecrypt(data, key []byte) []byte {
 	mode.XORKeyStream(decrypted, data)
 
 	decrypted = pkcs7UnPadding(decrypted)
+
 	return decrypted
 }

cryptor/des.go

@@ -15,7 +15,6 @@ import (
 // DesEcbEncrypt encrypt data with key use DES ECB algorithm
 // len(key) should be 8
 func DesEcbEncrypt(data, key []byte) []byte {
-	cipher, _ := des.NewCipher(generateDesKey(key))
 	length := (len(data) + des.BlockSize) / des.BlockSize
 	plain := make([]byte, length*des.BlockSize)
 	copy(plain, data)
@@ -26,6 +25,8 @@ func DesEcbEncrypt(data, key []byte) []byte {
 	}
 
 	encrypted := make([]byte, len(plain))
+	cipher, _ := des.NewCipher(generateDesKey(key))
+
 	for bs, be := 0, cipher.BlockSize(); bs <= len(data); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {
 		cipher.Encrypt(encrypted[bs:be], plain[bs:be])
 	}
@@ -59,6 +60,7 @@ func DesCbcEncrypt(data, key []byte) []byte {
 
 	encrypted := make([]byte, des.BlockSize+len(data))
 	iv := encrypted[:des.BlockSize]
+
 	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
 		panic(err)
 	}

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/hashmap/hashmap.go

@@ -93,6 +93,46 @@ func (hm *HashMap) Contains(key any) bool {
 	return node != nil
 }
 
+// Iterate executes iteratee funcation for every key and value pair of hashmap (random order)
+func (hm *HashMap) Iterate(iteratee func(key, value any)) {
+	if hm.size > 0 {
+		for i := 0; i < len(hm.table); i++ {
+			item := hm.table[i]
+			if item != nil {
+				iteratee(item.key, item.value)
+			}
+		}
+	}
+}
+
+// Keys returns a slice of the hashmap's keys (random order)
+func (hm *HashMap) Keys() []any {
+	keys := make([]any, int(hm.size))
+	index := 0
+	if hm.size > 0 {
+		hm.Iterate(func(key, value any) {
+			keys[index] = key
+			index++
+		})
+	}
+
+	return keys
+}
+
+// Values returns a slice of the hashmap's keys (random order)
+func (hm *HashMap) Values() []any {
+	values := make([]any, int(hm.size))
+	index := 0
+	if hm.size > 0 {
+		hm.Iterate(func(key, value any) {
+			values[index] = value
+			index++
+		})
+	}
+
+	return values
+}
+
 func (hm *HashMap) resize() {
 	hm.capacity <<= 1
 

datastructure/hashmap/hashmap_test.go

@@ -52,3 +52,20 @@ func TestHashMap_Contains(t *testing.T) {
 	hm.Put("abc", 3)
 	assert.Equal(true, hm.Contains("abc"))
 }
+
+func TestHashMap_KeysValues(t *testing.T) {
+	assert := internal.NewAssert(t, "TestHashMap_KeysValues")
+
+	hm := NewHashMap()
+
+	hm.Put("a", 1)
+	hm.Put("b", 2)
+	hm.Put("c", 3)
+
+	keys := hm.Keys()
+	values := hm.Values()
+	t.Log(keys, values)
+
+	assert.Equal(3, len(values))
+	assert.Equal(3, len(keys))
+}

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
+		dl.Head = newNode
-		link.length++
+		dl.length++
 		return
 	}
 
-	newNode.Next = link.Head
+	newNode.Next = dl.Head
 	newNode.Pre = nil
 
-	link.Head.Pre = newNode
+	dl.Head.Pre = newNode
-	link.Head = newNode
+	dl.Head = newNode
 
-	link.length++
+	dl.length++
 }
 
 // InsertAtTail insert value into doubly linklist at tail index
-func (link *DoublyLink[T]) InsertAtTail(value T) {
+func (dl *DoublyLink[T]) InsertAtTail(value T) {
-	current := link.Head
+	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 {
+// param `index` should between [0, length], if index do not meet the conditions, do nothing
-	size := link.length
+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)
+		dl.InsertAtHead(value)
-		return nil
+		return
 	}
 
 	if index == size {
-		link.InsertAtTail(value)
+		dl.InsertAtTail(value)
-		return nil
+		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 {
+func (dl *DoublyLink[T]) DeleteAtHead() {
-	if link.Head == nil {
+	if dl.Head == nil {
-		return errors.New("doubly link list no exist")
+		return
 	}
-	current := link.Head
-	link.Head = current.Next
-	link.Head.Pre = nil
-	link.length--
 
-	return nil
+	current := dl.Head
+	dl.Head = current.Next
+	dl.Head.Pre = nil
+	dl.length--
 }
 
-// DeleteAtTail delete value in doubly linklist at tail index
+// DeleteAtTail delete value in doubly linklist at tail
-func (link *DoublyLink[T]) DeleteAtTail() error {
+func (dl *DoublyLink[T]) DeleteAtTail() {
-	if link.Head == nil {
+	if dl.Head == nil {
-		return errors.New("doubly link list no exist")
+		return
 	}
-	current := link.Head
+
+	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--
+	dl.length--
-	return nil
 }
 
 // DeleteAt delete value in doubly linklist at index
-func (link *DoublyLink[T]) DeleteAt(index int) error {
+// param `index` should be [0, len(DoublyLink)-1]
-	if link.Head == nil {
+func (dl *DoublyLink[T]) DeleteAt(index int) {
-		return errors.New("doubly link list no exist")
+	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 {
+	if index == dl.length-1 {
-		return link.DeleteAtTail()
+		dl.DeleteAtTail()
 	}
 
-	if index < 0 || index > link.length-1 {
+	if index < 0 || index > dl.length-1 {
-		return errors.New("param index should between 0 and link size -1.")
+		return
 	}
 
 	i := 0
 	for current != nil {
 		if i == index-1 {
 			current.Next = current.Next.Next
-			link.length--
+			dl.length--
-			return nil
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("delete error")
 }
 
 // Reverse the linked list
-func (link *DoublyLink[T]) Reverse() {
+func (dl *DoublyLink[T]) Reverse() {
-	current := link.Head
+	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] {
+func (dl *DoublyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
-	if link.Head == nil {
+	if dl.Head == nil {
 		return nil
 	}
-	if link.Head.Next == nil {
+	if dl.Head.Next == nil {
-		return link.Head
+		return dl.Head
 	}
-	fast := link.Head
+	fast := dl.Head
-	slow := link.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 {
+func (dl *DoublyLink[T]) Size() int {
-	return link.length
+	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() {
+func (dl *DoublyLink[T]) Print() {
-	current := link.Head
+	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
+// IsEmpty checks if dl is empty or not
-func (link *DoublyLink[T]) IsEmpty() bool {
+func (dl *DoublyLink[T]) IsEmpty() bool {
-	return link.length == 0
+	return dl.length == 0
 }
 
 // Clear all nodes in doubly linklist
-func (link *DoublyLink[T]) Clear() {
+func (dl *DoublyLink[T]) Clear() {
-	link.Head = nil
+	dl.Head = nil
-	link.length = 0
+	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)
+	link.InsertAt(1, 1) //do nothing
-	assert.IsNotNil(err)
 
 	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()
+	link.DeleteAtHead()
-	assert.IsNotNil(err)
 
 	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()
+	link.DeleteAtTail()
-	assert.IsNotNil(err)
 
 	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)
+	link.DeleteAt(0)
-	assert.IsNotNil(err)
 
 	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)
+	link.DeleteAt(0)
-	assert.IsNotNil(err)
-
-	err = link.DeleteAt(0)
-	assert.IsNil(err)
 	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
+	newNode.Next = sl.Head
-	link.Head = newNode
+	sl.Head = newNode
-	link.length++
+	sl.length++
 }
 
 // InsertAtTail insert value into singly linklist at tail index
-func (link *SinglyLink[T]) InsertAtTail(value T) {
+func (sl *SinglyLink[T]) InsertAtTail(value T) {
-	current := link.Head
+	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 {
+// param `index` should between [0, len(SinglyLink)], if index do not meet the conditions, do nothing
-	size := link.length
+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)
+		sl.InsertAtHead(value)
-		return nil
+		return
 	}
 
 	if index == size {
-		link.InsertAtTail(value)
+		sl.InsertAtTail(value)
-		return nil
+		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++
+			sl.length++
-
+			return
-			return nil
 		}
 		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 {
+func (sl *SinglyLink[T]) DeleteAtHead() {
-	if link.Head == nil {
+	if sl.Head == nil {
-		return errors.New("singly link list no exist")
+		return
 	}
-	current := link.Head
-	link.Head = current.Next
-	link.length--
 
-	return nil
+	current := sl.Head
+	sl.Head = current.Next
+	sl.length--
 }
 
-// DeleteAtTail delete value in singly linklist at tail index
+// DeleteAtTail delete value in singly linklist at tail
-func (link *SinglyLink[T]) DeleteAtTail() error {
+func (sl *SinglyLink[T]) DeleteAtTail() {
-	if link.Head == nil {
+	if sl.Head == nil {
-		return errors.New("singly link list no exist")
+		return
 	}
-	current := link.Head
+
+	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--
+	sl.length--
-	return nil
 }
 
 // DeleteAt delete value in singly linklist at index
-func (link *SinglyLink[T]) DeleteAt(index int) error {
+// param `index` should be [0, len(SinglyLink)-1]
-	if link.Head == nil {
+func (sl *SinglyLink[T]) DeleteAt(index int) {
-		return errors.New("singly link list no exist")
+	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 {
+	if index == sl.length-1 {
-		return link.DeleteAtTail()
+		sl.DeleteAtTail()
 	}
 
-	if index < 0 || index > link.length-1 {
+	if index < 0 || index > sl.length-1 {
-		return errors.New("param index should between 0 and link size -1.")
+		return
 	}
 
 	i := 0
 	for current != nil {
 		if i == index-1 {
 			current.Next = current.Next.Next
-			link.length--
+			sl.length--
-			return nil
+			return
 		}
 		i++
 		current = current.Next
 	}
-
-	return errors.New("delete error")
 }
 
 // DeleteValue delete value in singly linklist
-func (link *SinglyLink[T]) DeleteValue(value T) {
+func (sl *SinglyLink[T]) DeleteValue(value T) {
-	if link.Head == nil {
+	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] {
+func (sl *SinglyLink[T]) GetMiddleNode() *datastructure.LinkNode[T] {
-	if link.Head == nil {
+	if sl.Head == nil {
 		return nil
 	}
-	if link.Head.Next == nil {
+	if sl.Head.Next == nil {
-		return link.Head
+		return sl.Head
 	}
-	fast := link.Head
+	fast := sl.Head
-	slow := link.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 {
+func (sl *SinglyLink[T]) Size() int {
-	return link.length
+	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
+// IsEmpty checks if sl is empty or not
-func (link *SinglyLink[T]) IsEmpty() bool {
+func (sl *SinglyLink[T]) IsEmpty() bool {
-	return link.length == 0
+	return sl.length == 0
 }
 
 // Clear all the node in singly linklist
-func (link *SinglyLink[T]) Clear() {
+func (sl *SinglyLink[T]) Clear() {
-	link.Head = nil
+	sl.Head = nil
-	link.length = 0
+	sl.length = 0
 }
 
 // Print all nodes info of a linked list
-func (link *SinglyLink[T]) Print() {
+func (sl *SinglyLink[T]) Print() {
-	current := link.Head
+	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)
+	link.InsertAt(1, 1) //do nothing
-	assert.IsNotNil(err)
 
-	err = link.InsertAt(0, 1)
+	link.InsertAt(0, 1)
-	if err != nil {
+	link.InsertAt(1, 2)
-		t.FailNow()
+	link.InsertAt(2, 4)
-	}
+	link.InsertAt(2, 3)
-	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.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)
+	link.DeleteAt(0)
-	assert.IsNotNil(err)
-
-	err = link.DeleteAt(0)
-	assert.IsNil(err)
 	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)
+	err := queue.Enqueue(1)
-	queue.Enqueue(2)
+	assert.IsNil(err)
-	queue.Enqueue(3)
+
-	queue.Enqueue(4)
+	err = queue.Enqueue(2)
-	queue.Enqueue(5)
+	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()
+	err = queue.Enqueue(2)
-	queue.Dequeue()
+	assert.IsNil(err)
-	queue.Enqueue(6)
-	queue.Enqueue(7)
 
-	queue.Print()
+	err = queue.Enqueue(3)
+	assert.IsNil(err)
 
 	val := queue.Front()
-	assert.Equal(3, val)
+	assert.IsNil(err)
-	assert.Equal(5, queue.Size())
+	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)
+	err := queue.Enqueue(1)
-	queue.Enqueue(2)
+	assert.IsNil(err)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
 
-	queue.Print()
+	err = queue.Enqueue(2)
-	assert.Equal(5, queue.Back())
+	assert.IsNil(err)
 
-	queue.Dequeue()
+	assert.Equal(2, queue.Back())
-	queue.Dequeue()
-	queue.Enqueue(6)
-	queue.Enqueue(7)
 
-	queue.Print()
+	val, _ := queue.Dequeue()
-	assert.Equal(7, queue.Back())
+	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 := NewCircularQueue[int](3)
-	queue.Enqueue(1)
+	err := queue.Enqueue(1)
-	queue.Enqueue(2)
+	assert.IsNil(err)
-	queue.Enqueue(3)
-	queue.Enqueue(4)
-	queue.Enqueue(5)
 
-	queue.Print()
+	err = queue.Enqueue(2)
-	assert.Equal([]int{1, 2, 3, 4, 5}, queue.Data())
+	assert.IsNil(err)
-
-	queue.Dequeue()
-	queue.Dequeue()
-	queue.Enqueue(6)
-	queue.Enqueue(7)
-
-	queue.Print()
-	assert.Equal([]int{3, 4, 5, 6, 7}, queue.Data())
 
+	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++ {
+	err := pq.Enqueue(1)
-		pq.Enqueue(i)
+	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++ {
+	err := pq.Enqueue(1)
-		pq.Enqueue(i)
+	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(3, val)
-
-	assert.Equal([]int{9, 8, 6, 7, 3, 2, 5, 1, 4}, pq.Data())
-
-	assert.Equal(9, pq.Size())
 }

datastructure/set/set.go

@@ -4,22 +4,59 @@ package datastructure
 type Set[T comparable] map[T]struct{}
 
 // NewSet return a instance of set
-func NewSet[T comparable](values ...T) Set[T] {
+func NewSet[T comparable](items ...T) Set[T] {
 	set := make(Set[T])
-	set.Add(values...)
+	set.Add(items...)
 	return set
 }
 
-// Add value to set
+// NewSetFromSlice create a set from slice
-func (s Set[T]) Add(values ...T) {
+func NewSetFromSlice[T comparable](items []T) Set[T] {
-	for _, v := range values {
+	set := make(Set[T])
+	for _, item := range items {
+		set.Add(item)
+	}
+	return set
+}
+
+// Add items to set
+func (s Set[T]) Add(items ...T) {
+	for _, v := range items {
 		s[v] = struct{}{}
 	}
 }
 
-// Contain checks if set contains value or not
+// AddIfNotExist checks if item exists in the set,
-func (s Set[T]) Contain(value T) bool {
+// it adds the item to set and returns true if it does not exist in the set,
-	_, ok := s[value]
+// or else it does nothing and returns false.
+func (s Set[T]) AddIfNotExist(item T) bool {
+	if !s.Contain(item) {
+		if _, ok := s[item]; !ok {
+			s[item] = struct{}{}
+			return true
+		}
+	}
+	return false
+}
+
+// AddIfNotExistBy checks if item exists in the set and pass the `checker` function
+// it adds the item to set and returns true if it does not exists in the set and
+// function `checker` returns true, or else it does nothing and returns false.
+func (s Set[T]) AddIfNotExistBy(item T, checker func(element T) bool) bool {
+	if !s.Contain(item) {
+		if checker(item) {
+			if _, ok := s[item]; !ok {
+				s[item] = struct{}{}
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// Contain checks if set contains item or not
+func (s Set[T]) Contain(item T) bool {
+	_, ok := s[item]
 	return ok
 }
 
@@ -41,9 +78,9 @@ func (s Set[T]) Clone() Set[T] {
 	return set
 }
 
-// Delete value of set
+// Delete item of set
-func (s Set[T]) Delete(values ...T) {
+func (s Set[T]) Delete(items ...T) {
-	for _, v := range values {
+	for _, v := range items {
 		delete(s, v)
 	}
 }
@@ -58,7 +95,7 @@ func (s Set[T]) Equal(other Set[T]) bool {
 }
 
 // Iterate call function by every element of set
-func (s Set[T]) Iterate(fn func(value T)) {
+func (s Set[T]) Iterate(fn func(item T)) {
 	for v := range s {
 		fn(v)
 	}
@@ -76,13 +113,13 @@ func (s Set[T]) Size() int {
 
 // Values return all values of set
 func (s Set[T]) Values() []T {
-	values := make([]T, 0, 0)
+	result := make([]T, 0, len(s))
 
 	s.Iterate(func(value T) {
-		values = append(values, value)
+		result = append(result, value)
 	})
 
-	return values
+	return result
 }
 
 // Union creates a new set contain all element of set s and other

datastructure/set/set_test.go

@@ -6,6 +6,19 @@ import (
 	"github.com/duke-git/lancet/v2/internal"
 )
 
+func TestSet_NewSetFromSlice(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSet_NewSetFromSlice")
+
+	s1 := NewSetFromSlice([]int{1, 2, 2, 3})
+	assert.Equal(3, s1.Size())
+	assert.Equal(true, s1.Contain(1))
+	assert.Equal(true, s1.Contain(2))
+	assert.Equal(true, s1.Contain(3))
+
+	s2 := NewSetFromSlice([]int{})
+	assert.Equal(0, s2.Size())
+}
+
 func TestSet_Add(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSet_Add")
 
@@ -17,6 +30,38 @@ func TestSet_Add(t *testing.T) {
 	assert.Equal(true, set.Equal(expected))
 }
 
+func TestSet_AddIfNotExist(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSet_AddIfNotExist")
+
+	set := NewSet[int]()
+	set.Add(1, 2, 3)
+
+	assert.Equal(false, set.AddIfNotExist(1))
+	assert.Equal(true, set.AddIfNotExist(4))
+	assert.Equal(NewSet(1, 2, 3, 4), set)
+}
+
+func TestSet_AddIfNotExistBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSet_AddIfNotExistBy")
+
+	set := NewSet[int]()
+	set.Add(1, 2)
+
+	ok := set.AddIfNotExistBy(3, func(val int) bool {
+		return val%2 != 0
+	})
+
+	notOk := set.AddIfNotExistBy(4, func(val int) bool {
+		return val%2 != 0
+	})
+
+	assert.Equal(true, ok)
+	assert.Equal(false, notOk)
+
+	assert.Equal(true, set.Contain(3))
+	assert.Equal(false, set.Contain(4))
+}
+
 func TestSet_Contain(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSet_Contain")
 

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

datetime/datetime.go

@@ -4,24 +4,24 @@
 // Package datetime implements some functions to format date and time.
 // Note:
 // 1. `format` param in FormatTimeToStr function should be as flow:
-//"yyyy-mm-dd hh:mm:ss"
+// "yyyy-mm-dd hh:mm:ss"
-//"yyyy-mm-dd hh:mm"
+// "yyyy-mm-dd hh:mm"
-//"yyyy-mm-dd hh"
+// "yyyy-mm-dd hh"
-//"yyyy-mm-dd"
+// "yyyy-mm-dd"
-//"yyyy-mm"
+// "yyyy-mm"
-//"mm-dd"
+// "mm-dd"
-//"dd-mm-yy hh:mm:ss"
+// "dd-mm-yy hh:mm:ss"
-//"yyyy/mm/dd hh:mm:ss"
+// "yyyy/mm/dd hh:mm:ss"
-//"yyyy/mm/dd hh:mm"
+// "yyyy/mm/dd hh:mm"
-//"yyyy/mm/dd hh"
+// "yyyy/mm/dd hh"
-//"yyyy/mm/dd"
+// "yyyy/mm/dd"
-//"yyyy/mm"
+// "yyyy/mm"
-//"mm/dd"
+// "mm/dd"
-//"dd/mm/yy hh:mm:ss"
+// "dd/mm/yy hh:mm:ss"
-//"yyyy"
+// "yyyy"
-//"mm"
+// "mm"
-//"hh:mm:ss"
+// "hh:mm:ss"
-//"mm:ss"
+// "mm:ss"
 package datetime
 
 import (
@@ -147,16 +147,32 @@ func EndOfDay(t time.Time) time.Time {
 	return time.Date(y, m, d, 23, 59, 59, int(time.Second-time.Nanosecond), t.Location())
 }
 
-// BeginOfWeek return beginning week, week begin from Sunday
+// BeginOfWeek return beginning week, default week begin from Sunday
-func BeginOfWeek(t time.Time) time.Time {
+func BeginOfWeek(t time.Time, beginFrom ...time.Weekday) time.Time {
-	y, m, d := t.AddDate(0, 0, 0-int(BeginOfDay(t).Weekday())).Date()
+	var beginFromWeekday = time.Sunday
-	return time.Date(y, m, d, 0, 0, 0, 0, t.Location())
+	if len(beginFrom) > 0 {
+		beginFromWeekday = beginFrom[0]
+	}
+	y, m, d := t.AddDate(0, 0, int(beginFromWeekday-t.Weekday())).Date()
+	beginOfWeek := time.Date(y, m, d, 0, 0, 0, 0, t.Location())
+	if beginOfWeek.After(t) {
+		return beginOfWeek.AddDate(0, 0, -7)
+	}
+	return beginOfWeek
 }
 
-// EndOfWeek return end week time, week end with Saturday
+// EndOfWeek return end week time, default week end with Saturday
-func EndOfWeek(t time.Time) time.Time {
+func EndOfWeek(t time.Time, endWith ...time.Weekday) time.Time {
-	y, m, d := BeginOfWeek(t).AddDate(0, 0, 7).Add(-time.Nanosecond).Date()
+	var endWithWeekday = time.Saturday
-	return time.Date(y, m, d, 23, 59, 59, int(time.Second-time.Nanosecond), t.Location())
+	if len(endWith) > 0 {
+		endWithWeekday = endWith[0]
+	}
+	y, m, d := t.AddDate(0, 0, int(endWithWeekday-t.Weekday())).Date()
+	var endWithWeek = time.Date(y, m, d, 23, 59, 59, int(time.Second-time.Nanosecond), t.Location())
+	if endWithWeek.Before(t) {
+		endWithWeek = endWithWeek.AddDate(0, 0, 7)
+	}
+	return endWithWeek
 }
 
 // BeginOfMonth return beginning of month

docs/algorithm.md

@@ -21,6 +21,7 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## Index
+
 - [BubbleSort](#BubbleSort)
 - [InsertionSort](#InsertionSort)
 - [SelectionSort](#SelectionSort)
@@ -31,7 +32,6 @@ import (
 - [CountSort](#CountSort)
 - [BinarySearch](#BinarySearch)
 - [BinaryIterativeSearch](#BinaryIterativeSearch)
-
 - [LinearSearch](#LinearSearch)
 - [LRUCache](#LRUCache)
 
@@ -570,6 +570,8 @@ func main() {
 func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V]
 func (l *LRUCache[K, V]) Get(key K) (V, bool)
 func (l *LRUCache[K, V]) Put(key K, value V)
+func (l *LRUCache[K, V]) Delete(key K) bool
+func (l *LRUCache[K, V]) Len() int
 ```
 <b>Example:</b>
 
@@ -586,10 +588,14 @@ func main() {
 
     cache.Put(1, 1)
     cache.Put(2, 2)
+    cache.Put(3, 3)
 
-    _, ok := cache.Get(0) // ok -> false
+    fmt.Println(cache.Len()) // 3
 
-    v, ok := cache.Get(1) // v->1, ok->true
+    v, ok := cache.Get(1)
+    fmt.Println(v, ok) // 1 true
 
+    ok = cache.Delete(1)
+    fmt.Println(ok) // true
 }
 ```

docs/algorithm_zh-CN.md

@@ -29,7 +29,6 @@ import (
 - [QuickSort](#QuickSort)
 - [HeapSort](#HeapSort)
 - [MergeSort](#MergeSort)
-
 - [CountSort](#CountSort)
 - [BinarySearch](#BinarySearch)
 - [BinaryIterativeSearch](#BinaryIterativeSearch)
@@ -571,6 +570,8 @@ func main() {
 func NewLRUCache[K comparable, V any](capacity int) *LRUCache[K, V]
 func (l *LRUCache[K, V]) Get(key K) (V, bool)
 func (l *LRUCache[K, V]) Put(key K, value V)
+func (l *LRUCache[K, V]) Delete(key K) bool
+func (l *LRUCache[K, V]) Len() int
 ```
 <b>Example:</b>
 
@@ -587,10 +588,14 @@ func main() {
 
     cache.Put(1, 1)
     cache.Put(2, 2)
+    cache.Put(3, 3)
 
-    _, ok := cache.Get(0) // ok -> false
+    fmt.Println(cache.Len()) // 3
 
-    v, ok := cache.Get(1) // v->1, ok->true
+    v, ok := cache.Get(1)
+    fmt.Println(v, ok) // 1 true
 
+    ok = cache.Delete(1)
+    fmt.Println(ok) // true
 }
 ```

docs/concurrency.md

@@ -38,13 +38,13 @@ import (
 
 ## Channel
 ### <span id="NewChannel">NewChannel</span>
-<p>return a Channel pointer instance.</p>
+<p>Create a Channel pointer instance.</p>
 
 <b>Signature:</b>
 
 ```go
-type Channel struct {}
+type Channel[T any] struct
-func NewChannel() *Channel
+func NewChannel[T any]() *Channel[T]
 ```
 <b>Example:</b>
 
@@ -57,7 +57,7 @@ import (
 )
 
 func main() {
-    c := concurrency.NewChannel()
+    c := concurrency.NewChannel[int]()
 }
 ```
 
@@ -70,7 +70,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (c *Channel) Bridge(ctx context.Context, chanStream <-chan <-chan any) <-chan any
+func (c *Channel[T]) Bridge(ctx context.Context, chanStream <-chan <-chan T) <-chan T
 ```
 <b>Example:</b>
 
@@ -87,25 +87,30 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	genVals := func() <-chan <-chan any {
+	genVals := func() <-chan <-chan int {
-		chanStream := make(chan (<-chan any))
+		out := make(chan (<-chan int))
 		go func() {
-			defer close(chanStream)
+			defer close(out)
-			for i := 0; i < 10; i++ {
+			for i := 1; i <= 5; i++ {
-				stream := make(chan any, 1)
+				stream := make(chan int, 1)
 				stream <- i
 				close(stream)
-				chanStream <- stream
+				out <- stream
 			}
 		}()
-		return chanStream
+		return out
 	}
 
-	index := 0
+	for v := range c.Bridge(ctx, genVals()) {
-	for val := range c.Bridge(ctx, genVals()) {
+		fmt.Println(v)
-		fmt.Printf("%v ", val) //0 1 2 3 4 5 6 7 8 9
 	}
+	// Output:
+	// 1
+	// 2
+	// 3
+	// 4
+	// 5
 }
 ```
 
@@ -114,12 +119,12 @@ func main() {
 
 ### <span id="FanIn">FanIn</span>
 
-<p>merge multiple channels into one channel until cancel the context.</p>
+<p>Merge multiple channels into one channel until cancel the context.</p>
 
 <b>Signature:</b>
 
 ```go
-func (c *Channel) FanIn(ctx context.Context, channels ...<-chan any) <-chan any
+func (c *Channel[T]) FanIn(ctx context.Context, channels ...<-chan T) <-chan T
 ```
 <b>Example:</b>
 
@@ -136,17 +141,17 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	channels := make([]<-chan any, 3)
+	channels := make([]<-chan int, 2)
 
-	for i := 0; i < 3; i++ {
+	for i := 0; i < 2; i++ {
-		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 3)
+		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 2)
 	}
 
-	mergedChannel := c.FanIn(ctx, channels...)
+	chs := c.FanIn(ctx, channels...)
 
-	for val := range mergedChannel {
+	for v := range chs {
-		fmt.Println("\t%d\n", val) //1,2,1,0,0,1,0,2,2 (order not for sure)
+		fmt.Println(v) //1 1 0 0 or 0 0 1 1
 	}
 }
 ```
@@ -154,12 +159,12 @@ func main() {
 
 ### <span id="Repeat">Repeat</span>
 
-<p>Return a chan, put param `values` into the chan repeatly until cancel the context.</p>
+<p>Create channel, put values into the channel repeatly until cancel the context.</p>
 
 <b>Signature:</b>
 
 ```go
-func (c *Channel) Repeat(ctx context.Context, values ...any) <-chan any
+func (c *Channel[T]) Repeat(ctx context.Context, values ...T) <-chan T
 ```
 <b>Example:</b>
 
@@ -176,26 +181,30 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 5)
+	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 4)
 
 	for v := range intStream {
-	fmt.Println(v) //1, 2, 1, 2, 1
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 2
+	// 1
+	// 2
 }
 ```
 
 
 
+### <span id="Generate">Generate</span>
 
-### <span id="RepeatFn">RepeatFn</span>
+<p>Creates a channel, then put values into the channel.</p>
-
-<p>Return a chan, excutes fn repeatly, and put the result into retruned chan until cancel context.</p>
 
 <b>Signature:</b>
 
 ```go
-func (c *Channel) RepeatFn(ctx context.Context, fn func() any) <-chan any
+func (c *Channel[T]) Generate(ctx context.Context, values ...T) <-chan T
 ```
 <b>Example:</b>
 
@@ -212,16 +221,58 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	fn := func() any {
+	c := concurrency.NewChannel[int]()
-		s := "a"
+	intStream := c.Generate(ctx, 1, 2, 3)
-		return s
-	}
-	c := concurrency.NewChannel()
-	dataStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
 
-	for v := range dataStream {
+	fmt.Println(<-intStream)
-		fmt.Println(v) //a, a, a
+	fmt.Println(<-intStream)
+	fmt.Println(<-intStream)
+
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+```
+
+### <span id="RepeatFn">RepeatFn</span>
+
+<p>Create a channel, excutes fn repeatly, and put the result into the channel, until close context.</p>
+
+<b>Signature:</b>
+
+```go
+func (c *Channel[T]) RepeatFn(ctx context.Context, fn func() T) <-chan T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "github.com/duke-git/lancet/v2/concurrency"
+)
+
+func main() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	fn := func() string {
+		return "hello"
 	}
+
+	c := concurrency.NewChannel[string]()
+	intStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
+
+	for v := range intStream {
+		fmt.Println(v)
+	}
+	// Output:
+	// hello
+	// hello
+	// hello
 }
 ```
 
@@ -234,7 +285,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (c *Channel) Or(channels ...<-chan any) <-chan any
+func (c *Channel[T]) Or(channels ...<-chan T) <-chan T
 ```
 <b>Example:</b>
 
@@ -249,7 +300,7 @@ import (
 
 func main() {
 	sig := func(after time.Duration) <-chan any {
-		c := make(chan interface{})
+		c := make(chan any)
 		go func() {
 			defer close(c)
 			time.Sleep(after)
@@ -259,13 +310,11 @@ func main() {
 
 	start := time.Now()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[any]()
 	<-c.Or(
 		sig(1*time.Second),
 		sig(2*time.Second),
 		sig(3*time.Second),
-		sig(4*time.Second),
-		sig(5*time.Second),
 	)
 
 	fmt.Println("done after %v", time.Since(start)) //1.003s
@@ -282,7 +331,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (c *Channel) OrDone(ctx context.Context, channel <-chan any) <-chan any
+func (c *Channel[T]) OrDone(ctx context.Context, channel <-chan T) <-chan T
 ```
 <b>Example:</b>
 
@@ -299,12 +348,16 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
 	intStream := c.Take(ctx, c.Repeat(ctx, 1), 3)
 
-	for val := range c.OrDone(ctx, intStream) {
+	for v := range c.OrDone(ctx, intStream) {
-		fmt.Println(val)  //1
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 1
+	// 1
 }
 ```
 
@@ -313,12 +366,12 @@ func main() {
 
 ### <span id="Take">Take</span>
 
-<p>Return a chan whose values are tahken from another chan until cancel context.</p>
+<p>Create a channel whose values are taken from another channel with limit number.</p>
 
 <b>Signature:</b>
 
 ```go
-func (c *Channel) Take(ctx context.Context, valueStream <-chan any, number int) <-chan any
+func (c *Channel[T]) Take(ctx context.Context, valueStream <-chan T, number int) <-chan T
 ```
 <b>Example:</b>
 
@@ -335,7 +388,7 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	numbers := make(chan any, 5)
+	numbers := make(chan int, 5)
 	numbers <- 1
 	numbers <- 2
 	numbers <- 3
@@ -343,12 +396,16 @@ func main() {
 	numbers <- 5
 	defer close(numbers)
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
 	intStream := c.Take(ctx, numbers, 3)
 
-	for val := range intStream {
+	for v := range intStream {
-		fmt.Println(val) //1, 2, 3
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 2
+	// 3
 }
 ```
 
@@ -356,12 +413,12 @@ func main() {
 
 ### <span id="Tee">Tee</span>
 
-<p>Split one chanel into two channels until cancel context.</p>
+<p>Split one chanel into two channels, until cancel the context.</p>
 
 <b>Signature:</b>
 
 ```go
-func (c *Channel) Tee(ctx context.Context, in <-chan any) (<-chan any, <-chan any)
+func (c *Channel[T]) Tee(ctx context.Context, in <-chan T) (<-chan T, <-chan T)
 ```
 <b>Example:</b>
 
@@ -378,13 +435,19 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	inStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 4)
+	intStream := c.Take(ctx, c.Repeat(ctx, 1), 2)
 
-	out1, out2 := c.Tee(ctx, inStream)
+	ch1, ch2 := c.Tee(ctx, intStream)
-	for val := range out1 {
+
-		fmt.Println(val) //1
+	for v := range ch1 {
-		fmt.Println(<-out2) //1
+		fmt.Println(v)
+		fmt.Println(<-ch2)
 	}
+	// Output:
+	// 1
+	// 1
+	// 1
+	// 1
 }
 ```

docs/concurrency_zh-CN.md

@@ -38,13 +38,13 @@ import (
 
 ### Channel
 ### <span id="NewChannel">NewChannel</span>
-<p>返回一个 Channel 指针实例</p>
+<p>返回一个Channel指针实例</p>
 
 <b>函数签名:</b>
 
 ```go
-type Channel struct {}
+type Channel[T any] struct
-func NewChannel() *Channel
+func NewChannel[T any]() *Channel[T]
 ```
 <b>例子:</b>
 
@@ -57,7 +57,7 @@ import (
 )
 
 func main() {
-    c := concurrency.NewChannel()
+    c := concurrency.NewChannel[int]()
 }
 ```
 
@@ -65,12 +65,12 @@ func main() {
 
 ### <span id="Bridge">Bridge</span>
 
-<p>将多个通道链接到一个通道，直到取消上下文。</p>
+<p>将多个channel链接到一个channel，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) Bridge(ctx context.Context, chanStream <-chan <-chan any) <-chan any
+func (c *Channel[T]) Bridge(ctx context.Context, chanStream <-chan <-chan T) <-chan T
 ```
 <b>例子:</b>
 
@@ -84,28 +84,33 @@ import (
 )
 
 func main() {
-    ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	genVals := func() <-chan <-chan any {
+	genVals := func() <-chan <-chan int {
-		chanStream := make(chan (<-chan any))
+		out := make(chan (<-chan int))
 		go func() {
-			defer close(chanStream)
+			defer close(out)
-			for i := 0; i < 10; i++ {
+			for i := 1; i <= 5; i++ {
-				stream := make(chan any, 1)
+				stream := make(chan int, 1)
 				stream <- i
 				close(stream)
-				chanStream <- stream
+				out <- stream
 			}
 		}()
-		return chanStream
+		return out
 	}
 
-	index := 0
+	for v := range c.Bridge(ctx, genVals()) {
-	for val := range c.Bridge(ctx, genVals()) {
+		fmt.Println(v)
-		fmt.Printf("%v ", val) //0 1 2 3 4 5 6 7 8 9
 	}
+	// Output:
+	// 1
+	// 2
+	// 3
+	// 4
+	// 5
 }
 ```
 
@@ -114,12 +119,12 @@ func main() {
 
 ### <span id="FanIn">FanIn</span>
 
-<p>将多个通道合并为一个通道，直到取消上下文</p>
+<p>将多个channel合并为一个channel，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) FanIn(ctx context.Context, channels ...<-chan any) <-chan any
+func (c *Channel[T]) FanIn(ctx context.Context, channels ...<-chan T) <-chan T
 ```
 <b>例子:</b>
 
@@ -133,33 +138,33 @@ import (
 )
 
 func main() {
-    ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	channels := make([]<-chan any, 3)
+	channels := make([]<-chan int, 2)
 
-	for i := 0; i < 3; i++ {
+	for i := 0; i < 2; i++ {
-		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 3)
+		channels[i] = c.Take(ctx, c.Repeat(ctx, i), 2)
 	}
 
-	mergedChannel := c.FanIn(ctx, channels...)
+	chs := c.FanIn(ctx, channels...)
 
-	for val := range mergedChannel {
+	for v := range chs {
-		fmt.Println("\t%d\n", val) //1,2,1,0,0,1,0,2,2 (order not for sure)
+		fmt.Println(v) //1 1 0 0 or 0 0 1 1
 	}
 }
 ```
 
 
-### <span id="Repeat">Repeat</span>
+### <span id="Generate">Generate</span>
 
-<p>返回一个chan，将参数`values`重复放入chan，直到取消上下文。</p>
+<p>根据传入的值，生成channel.</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) Repeat(ctx context.Context, values ...any) <-chan any
+func (c *Channel[T]) Generate(ctx context.Context, values ...T) <-chan T
 ```
 <b>例子:</b>
 
@@ -173,15 +178,58 @@ import (
 )
 
 func main() {
-    ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 5)
+	intStream := c.Generate(ctx, 1, 2, 3)
+
+	fmt.Println(<-intStream)
+	fmt.Println(<-intStream)
+	fmt.Println(<-intStream)
+
+	// Output:
+	// 1
+	// 2
+	// 3
+}
+```
+
+### <span id="Repeat">Repeat</span>
+
+<p>返回一个channel，将参数`values`重复放入channel，直到取消上下文。</p>
+
+<b>函数签名:</b>
+
+```go
+func (c *Channel[T]) Repeat(ctx context.Context, values ...T) <-chan T
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "context"
+    "fmt"
+    "github.com/duke-git/lancet/v2/concurrency"
+)
+
+func main() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	c := concurrency.NewChannel[int]()
+	intStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 4)
 
 	for v := range intStream {
-		fmt.Println(v) //1, 2, 1, 2, 1
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 2
+	// 1
+	// 2
 }
 ```
 
@@ -190,12 +238,12 @@ func main() {
 
 ### <span id="RepeatFn">RepeatFn</span>
 
-<p>返回一个chan，重复执行函数fn，并将结果放入返回的chan，直到取消上下文。</p>
+<p>返回一个channel，重复执行函数fn，并将结果放入返回的channel，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) RepeatFn(ctx context.Context, fn func() any) <-chan any
+func (c *Channel[T]) RepeatFn(ctx context.Context, fn func() T) <-chan T
 ```
 <b>例子:</b>
 
@@ -209,19 +257,23 @@ import (
 )
 
 func main() {
-    ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	fn := func() any {
+	fn := func() string {
-		s := "a"
+		return "hello"
-		return s
 	}
-	c := concurrency.NewChannel()
-	dataStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
 
-	for v := range dataStream {
+	c := concurrency.NewChannel[string]()
-		fmt.Println(v) //a, a, a
+	intStream := c.Take(ctx, c.RepeatFn(ctx, fn), 3)
+
+	for v := range intStream {
+		fmt.Println(v)
 	}
+	// Output:
+	// hello
+	// hello
+	// hello
 }
 ```
 
@@ -229,12 +281,12 @@ func main() {
 
 ### <span id="Or">Or</span>
 
-<p>将一个或多个通道读取到一个通道中，当任何读取通道关闭时将结束读取。</p>
+<p>将一个或多个channel读取到一个channel中，当任何读取channel关闭时将结束读取。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) Or(channels ...<-chan any) <-chan any
+func (c *Channel[T]) Or(channels ...<-chan T) <-chan T
 ```
 <b>例子:</b>
 
@@ -249,7 +301,7 @@ import (
 
 func main() {
 	sig := func(after time.Duration) <-chan any {
-		c := make(chan interface{})
+		c := make(chan any)
 		go func() {
 			defer close(c)
 			time.Sleep(after)
@@ -259,13 +311,11 @@ func main() {
 
 	start := time.Now()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[any]()
 	<-c.Or(
 		sig(1*time.Second),
 		sig(2*time.Second),
 		sig(3*time.Second),
-		sig(4*time.Second),
-		sig(5*time.Second),
 	)
 
 	fmt.Println("done after %v", time.Since(start)) //1.003s
@@ -277,12 +327,12 @@ func main() {
 
 ### <span id="OrDone">OrDone</span>
 
-<p>将一个通道读入另一个通道，直到取消上下文。</p>
+<p>将一个channel读入另一个channel，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) OrDone(ctx context.Context, channel <-chan any) <-chan any
+func (c *Channel[T]) OrDone(ctx context.Context, channel <-chan T) <-chan T
 ```
 <b>例子:</b>
 
@@ -299,12 +349,16 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
 	intStream := c.Take(ctx, c.Repeat(ctx, 1), 3)
 
-	for val := range c.OrDone(ctx, intStream) {
+	for v := range c.OrDone(ctx, intStream) {
-		fmt.Println(val)  //1
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 1
+	// 1
 }
 ```
 
@@ -313,12 +367,12 @@ func main() {
 
 ### <span id="Take">Take</span>
 
-<p>返回一个chan，其值从另一个chan获取，直到取消上下文。</p>
+<p>返回一个channel，其值从另一个channel获取，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) Take(ctx context.Context, valueStream <-chan any, number int) <-chan any
+func (c *Channel[T]) Take(ctx context.Context, valueStream <-chan T, number int) <-chan T
 ```
 <b>例子:</b>
 
@@ -335,7 +389,7 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	numbers := make(chan any, 5)
+	numbers := make(chan int, 5)
 	numbers <- 1
 	numbers <- 2
 	numbers <- 3
@@ -343,12 +397,16 @@ func main() {
 	numbers <- 5
 	defer close(numbers)
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
 	intStream := c.Take(ctx, numbers, 3)
 
-	for val := range intStream {
+	for v := range intStream {
-		fmt.Println(val) //1, 2, 3
+		fmt.Println(v)
 	}
+	// Output:
+	// 1
+	// 2
+	// 3
 }
 ```
 
@@ -356,12 +414,12 @@ func main() {
 
 ### <span id="Tee">Tee</span>
 
-<p>将一个通道分成两个通道，直到取消上下文。</p>
+<p>将一个channel分成两个channel，直到取消上下文。</p>
 
 <b>函数签名:</b>
 
 ```go
-func (c *Channel) Tee(ctx context.Context, in <-chan any) (<-chan any, <-chan any)
+func (c *Channel[T]) Tee(ctx context.Context, in <-chan T) (<-chan T, <-chan T)
 ```
 <b>例子:</b>
 
@@ -378,13 +436,19 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	c := concurrency.NewChannel()
+	c := concurrency.NewChannel[int]()
-	inStream := c.Take(ctx, c.Repeat(ctx, 1, 2), 4)
+	intStream := c.Take(ctx, c.Repeat(ctx, 1), 2)
 
-	out1, out2 := c.Tee(ctx, inStream)
+	ch1, ch2 := c.Tee(ctx, intStream)
-	for val := range out1 {
+
-		fmt.Println(val) //1
+	for v := range ch1 {
-		fmt.Println(<-out2) //1
+		fmt.Println(v)
+		fmt.Println(<-ch2)
 	}
+	// Output:
+	// 1
+	// 1
+	// 1
+	// 1
 }
 ```

docs/condition.md

@@ -25,6 +25,7 @@ import (
 - [Or](#Or)
 - [Xor](#Generate)
 - [Nor](#Nor)
+- [Xnor](#Xnor)
 - [Nand](#Nand)
 - [TernaryOperator](#TernaryOperator)
 
@@ -120,7 +121,7 @@ func main() {
 
 
 ### <span id="Or">Or</span>
-<p>Returns false iff neither a nor b is truthy.</p>
+<p>Returns false if neither a nor b is truthy.</p>
 
 <b>Signature:</b>
 
@@ -148,7 +149,7 @@ func main() {
 
 
 ### <span id="Xor">Xor</span>
-<p>Returns true iff a or b but not both is truthy.</p>
+<p>Returns true if a or b but not both is truthy.</p>
 
 <b>Signature:</b>
 
@@ -176,7 +177,7 @@ func main() {
 
 
 ### <span id="Nor">Nor</span>
-<p>Returns true iff neither a nor b is truthy.</p>
+<p>Returns true if neither a nor b is truthy.</p>
 
 <b>Signature:</b>
 
@@ -197,14 +198,40 @@ func main() {
 	fmt.Println(condition.Nor(0, 0)) // true
 	fmt.Println(condition.Nor(0, 1)) // false
 	fmt.Println(condition.Nor(1, 0)) // false
-	fmt.Println(condition.Nor(1, 1)) // true
+	fmt.Println(condition.Nor(1, 1)) // false
 }
 ```
 
 
+### <span id="Xnor">Xnor</span>
+<p>Returns true if both a and b or neither a nor b are truthy.</p>
+
+<b>Signature:</b>
+
+```go
+func Xnor[T, U any](a T, b U) bool
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/condition"
+)
+
+func main() {
+	fmt.Println(condition.Xnor(0, 0)) // true
+	fmt.Println(condition.Xnor(0, 1)) // false
+	fmt.Println(condition.Xnor(1, 0)) // false
+	fmt.Println(condition.Xnor(1, 1)) // true
+}
+```
+
 
 ### <span id="Nand">Nand</span>
-<p>Returns false iff both a and b are truthy</p>
+<p>Returns false if both a and b are truthy</p>
 
 <b>Signature:</b>
 

docs/condition_zh-CN.md

@@ -25,6 +25,7 @@ import (
 - [Or](#Or)
 - [Xor](#Generate)
 - [Nor](#Nor)
+- [Xnor](#Xnor)
 - [Nand](#Nand)
 - [TernaryOperator](#TernaryOperator)
 
@@ -196,12 +197,38 @@ func main() {
 	fmt.Println(condition.Nor(0, 0)) // true
 	fmt.Println(condition.Nor(0, 1)) // false
 	fmt.Println(condition.Nor(1, 0)) // false
-	fmt.Println(condition.Nor(1, 1)) // true
+	fmt.Println(condition.Nor(1, 1)) // false
 }
 ```
 
 
 
+### <span id="Xnor">Xnor</span>
+<p>如果a和b都是真的或a和b均是假的，则返回true。</p>
+
+<b>函数签名:</b>
+
+```go
+func Xnor[T, U any](a T, b U) bool
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/condition"
+)
+
+func main() {
+	fmt.Println(condition.Xnor(0, 0)) // true
+	fmt.Println(condition.Xnor(0, 1)) // false
+	fmt.Println(condition.Xnor(1, 0)) // false
+	fmt.Println(condition.Xnor(1, 1)) // true
+}
+```
+
 ### <span id="Nand">Nand</span>
 <p>如果a和b都为真，返回false，否则返回true</p>
 

docs/convertor.md

@@ -25,7 +25,6 @@ import (
 - [ToBytes](#ToBytes)
 - [ToChar](#ToChar)
 - [ToChannel](#ToChannel)
-
 - [ToFloat](#ToFloat)
 - [ToInt](#ToInt)
 - [ToJson](#ToJson)
@@ -103,7 +102,7 @@ func main() {
 
 ### <span id="ToBool">ToBool</span>
 
-<p>Convert string to a boolean value. Use strconv.ParseBool</p>
+<p>Convert string to bool. Use strconv.ParseBool.</p>
 
 <b>Signature:</b>
 
@@ -139,7 +138,7 @@ func main() {
 
 ### <span id="ToBytes">ToBytes</span>
 
-<p>Convert interface to byte slice.</p>
+<p>Convert value to byte slice.</p>
 
 <b>Signature:</b>
 
@@ -201,7 +200,7 @@ func main() {
 
 ### <span id="ToChannel">ToChannel</span>
 
-<p>Convert a collection of elements to a read-only channels.</p>
+<p>Convert a collection of elements to a read-only channel.</p>
 
 <b>Signature:</b>
 
@@ -239,7 +238,7 @@ func main() {
 
 ### <span id="ToFloat">ToFloat</span>
 
-<p>Convert interface to a float64 value. If param is a invalid floatable, will return 0 and error. </p>
+<p>Convert value to a float64 value. If param is a invalid floatable, will return 0.0 and error. </p>
 
 <b>Signature:</b>
 
@@ -272,7 +271,7 @@ func main() {
 
 ### <span id="ToInt">ToInt</span>
 
-<p>Convert interface to a int64 value. If param is a invalid intable, will return 0 and error. </p>
+<p>Convert value to a int64 value. If param is a invalid intable, will return 0 and error. </p>
 
 <b>Signature:</b>
 
@@ -333,7 +332,7 @@ func main() {
 
 ### <span id="ToMap">ToMap</span>
 
-<p>Convert a slice or an array of structs to a map based on iteratee function. </p>
+<p>Convert a slice of structs to a map based on iteratee function. </p>
 
 <b>Signature:</b>
 
@@ -395,6 +394,32 @@ func main() {
 ```
 
 
+### <span id="ToString">ToString</span>
+
+<p>ToString convert value to string, for number, string, []byte, will convert to string. For other type (slice, map, array, struct) will call json.Marshal</p>
+
+<b>Signature:</b>
+
+```go
+func ToString(value any) string
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/convertor"
+)
+
+func main() {
+    fmt.Printf("%q", convertor.ToString(1)) //"1"
+    fmt.Printf("%q", convertor.ToString(1.1)) //"1.1"
+    fmt.Printf("%q", convertor.ToString([]int{1, 2, 3})) //"[1,2,3]"
+}
+```
+
 
 ### <span id="StructToMap">StructToMap</span>
 

docs/convertor_zh-CN.md

@@ -27,7 +27,6 @@ import (
 - [ToBytes](#ToBytes)
 - [ToChar](#ToChar)
 - [ToChannel](#ToChannel)
-
 - [ToFloat](#ToFloat)
 - [ToInt](#ToInt)
 - [ToJson](#ToJson)
@@ -401,7 +400,7 @@ func main() {
 
 ### <span id="ToString">ToString</span>
 
-<p>将interface转成字符串</p>
+<p>将值转换为字符串，对于数字、字符串、[]byte，将转换为字符串。 对于其他类型（切片、映射、数组、结构）将调用 json.Marshal</p>
 
 <b>函数签名:</b>
 
@@ -523,7 +522,7 @@ func main() {
 
 ### <span id="DecodeByte">DecodeByte</span>
 
-<p>解码字节切片到目标对象，目标对象需要传入一个指针实例子</p>
+<p>解码字节切片到目标对象，目标对象需要传入一个指针实例</p>
 
 <b>函数签名:</b>
 

docs/cryptor.md

@@ -47,7 +47,6 @@ import (
 - [HmacSha1](#HmacSha1)
 - [HmacSha256](#HmacSha256)
 - [HmacSha512](#HmacSha512)
-
 - [Md5String](#Md5String)
 - [Md5File](#Md5File)
 - [Sha1](#Sha1)

docs/cryptor_zh-CN.md

@@ -33,7 +33,6 @@ import (
 - [AesOfbDecrypt](#AesOfbDecrypt)
 - [Base64StdEncode](#Base64StdEncode)
 - [Base64StdDecode](#Base64StdDecode)
-
 - [DesEcbEncrypt](#DesEcbEncrypt)
 - [DesEcbDecrypt](#DesEcbDecrypt)
 - [DesCbcEncrypt](#DesCbcEncrypt)
@@ -43,7 +42,6 @@ import (
 - [DesCfbDecrypt](#DesCfbDecrypt)
 - [DesOfbEncrypt](#DesOfbEncrypt)
 - [DesOfbDecrypt](#DesOfbDecrypt)
-
 - [HmacMd5](#HmacMd5)
 - [HmacSha1](#HmacSha1)
 - [HmacSha256](#HmacSha256)

docs/datastructure/hashmap.md

@@ -29,6 +29,9 @@ import (
 - [Put](#Put)
 - [Delete](#Delete)
 - [Contains](#Contains)
+- [Iterate](#Iterate)
+- [Keys](#Keys)
+- [Values](#Values)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -207,3 +210,105 @@ func main() {
     fmt.Println(hm.Contains("b")) //false
 }
 ```
+
+
+
+### <span id="Iterate">Iterate</span>
+
+<p>Executes iteratee funcation for every key and value pair of hashmap.</p>
+
+<b>Signature:</b>
+
+```go
+func (hm *HashMap) Iterate(iteratee func(key, value any))
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    hm.Iterate(func(key, value any) {
+        fmt.Println(key)
+        fmt.Println(value)
+    })
+}
+```
+
+
+
+### <span id="Keys">Keys</span>
+
+<p>Return a slice of the hashmap's keys (random order).</p>
+
+<b>Signature:</b>
+
+```go
+func (hm *HashMap) Keys() []any
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    keys := hm.Keys()
+    fmt.Println(keys) //[]interface{"a", "b", "c"}
+}
+```
+
+
+### <span id="Values">Values</span>
+
+<p>Return a slice of the hashmap's values (random order).</p>
+
+<b>Signature:</b>
+
+```go
+func (hm *HashMap) Values() []any
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    values := hm.Values()
+    fmt.Println(values) //[]interface{2, 1, 3}
+}
+```
+
+

docs/datastructure/hashmap_zh-CN.md

@@ -24,11 +24,13 @@ import (
 
 - [NewHashMap](#NewHashMap)
 - [NewHashMapWithCapacity](#NewHashMapWithCapacity)
-
 - [Get](#Get)
 - [Put](#Put)
 - [Delete](#Delete)
 - [Contains](#Contains)
+- [Iterate](#Iterate)
+- [Keys](#Keys)
+- [Values](#Values)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -203,3 +205,104 @@ func main() {
     fmt.Println(hm.Contains("b")) //false
 }
 ```
+
+
+### <span id="Iterate">Iterate</span>
+
+<p>迭代hashmap，对每个key和value执行iteratee函数</p>
+
+<b>函数签名:</b>
+
+```go
+func (hm *HashMap) Iterate(iteratee func(key, value any))
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    hm.Iterate(func(key, value any) {
+        fmt.Println(key)
+        fmt.Println(value)
+    })
+}
+```
+
+
+
+### <span id="Keys">Keys</span>
+
+<p>返回hashmap所有key的切片 (随机顺序)</p>
+
+<b>函数签名:</b>
+
+```go
+func (hm *HashMap) Keys() []any
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    keys := hm.Keys()
+    fmt.Println(keys) //[]interface{"a", "b", "c"}
+}
+```
+
+
+### <span id="Values">Values</span>
+
+<p>返回hashmap所有值的切片 (随机顺序).</p>
+
+<b>函数签名:</b>
+
+```go
+func (hm *HashMap) Values() []any
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    hashmap "github.com/duke-git/lancet/v2/datastructure/hashmap"
+)
+
+func main() {
+    hm := heap.NewHashMap()
+    hm.Put("a", 1)
+    hm.Put("b", 2)
+    hm.Put("c", 3)
+
+    values := hm.Values()
+    fmt.Println(values) //[]interface{2, 1, 3}
+}
+```
+
+

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

@@ -132,12 +132,12 @@ func main() {
 
 
 ### <span id="SinglyLink_InsertAt">InsertAt</span>
-<p>将值插入到索引处的链表中，索引应大于或等于 0 且小于或等于链表节点数</p>
+<p>将值插入到索引处的链表中，索引应大于或等于0且小于或等于链表节点数</p>
 
 <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)
@@ -228,12 +230,12 @@ func main() {
 
 
 ### <span id="SinglyLink_DeleteAt">DeleteAt</span>
-<p>删除特定索引处的值，索引应大于或等于0且小于或等于链接节点数 - 1</p>
+<p>删除特定索引处的值，索引应大于或等于0且小于或等于链接节点数-1</p>
 
 <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}
 }
 ```
@@ -628,12 +627,12 @@ func main() {
 
 
 ### <span id="DoublyLink_InsertAt">InsertAt</span>
-<p>将值插入到索引处的链表中，索引应大于或等于 0 且小于或等于链表节点数</p>
+<p>将值插入到索引处的链表中，索引应大于或等于0且小于或等于链表节点数</p>
 
 <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)
@@ -724,12 +725,12 @@ func main() {
 
 
 ### <span id="DoublyLink_DeleteAt">DeleteAt</span>
-<p>删除特定索引处的值，索引应大于或等于0且小于或等于链接节点数 - 1</p>
+<p>删除特定索引处的值，索引应大于或等于0且小于或等于链接节点数-1</p>
 
 <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/datastructure/set.md

@@ -22,8 +22,11 @@ import (
 ## Index
 
 - [NewSet](#NewSet)
+- [NewSetFromSlice](#NewSetFromSlice)
 - [Values](#Values)
 - [Add](#Add)
+- [AddIfNotExist](#AddIfNotExist)
+- [AddIfNotExistBy](#AddIfNotExistBy)
 - [Delete](#Delete)
 - [Contain](#Contain)
 - [ContainAll](#ContainAll)
@@ -34,7 +37,6 @@ import (
 - [IsEmpty](#IsEmpty)
 - [Union](#Union)
 - [Intersection](#Intersection)
-
 - [SymmetricDifference](#SymmetricDifference)
 - [Minus](#Minus)
 
@@ -45,13 +47,13 @@ import (
 ## Documentation
 
 ### <span id="NewSet">NewSet</span>
-<p>Make a Set instance</p>
+<p>Create a set instance</p>
 
 <b>Signature:</b>
 
 ```go
 type Set[T comparable] map[T]bool
-func NewSet[T comparable](values ...T) Set[T]
+func NewSet[T comparable](items ...T) Set[T]
 ```
 <b>Example:</b>
 
@@ -70,6 +72,30 @@ func main() {
 ```
 
 
+### <span id="NewSetFromSlice">NewSetFromSlice</span>
+<p>Create a set from slice</p>
+
+<b>Signature:</b>
+
+```go
+func NewSetFromSlice[T comparable](items []T) Set[T]
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSetFromSlice([]int{1, 2, 2, 3})
+    fmt.Println(st.Values()) //1,2,3
+}
+```
+
 
 
 ### <span id="Values">Values</span>
@@ -100,12 +126,12 @@ func main() {
 
 
 ### <span id="Add">Add</span>
-<p>Add value to set</p>
+<p>Add items to set</p>
 
 <b>Signature:</b>
 
 ```go
-func (s Set[T]) Add(values ...T)
+func (s Set[T]) Add(items ...T)
 ```
 <b>Example:</b>
 
@@ -126,14 +152,83 @@ func main() {
 ```
 
 
-
+### <span id="AddIfNotExist">AddIfNotExist</span>
-### <span id="Delete">Delete</span>
+<p>AddIfNotExist checks if item exists in the set, it adds the item to set and returns true if it does not exist in the set, or else it does nothing and returns false.</p>
-<p>Delete value in set</p>
 
 <b>Signature:</b>
 
 ```go
-func (s Set[T]) Delete(values ...T)
+func (s Set[T]) AddIfNotExist(item T) bool
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSet[int]()
+    st.Add(1, 2, 3)
+
+    r1 := st.AddIfNotExist(1)
+	r2 := st.AddIfNotExist(4)
+
+    fmt.Println(r1) // false
+    fmt.Println(r2) // true
+    fmt.Println(st.Values()) // 1,2,3,4
+}
+```
+
+
+### <span id="AddIfNotExistBy">AddIfNotExistBy</span>
+<p>AddIfNotExistBy checks if item exists in the set and pass the `checker` function it adds the item to set and returns true if it does not exists in the set and function `checker` returns true, or else it does nothing and returns false.</p>
+
+<b>Signature:</b>
+
+```go
+func (s Set[T]) AddIfNotExistBy(item T, checker func(element T) bool) bool
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSet[int]()
+    st.Add(1, 2)
+
+	ok := st.AddIfNotExistBy(3, func(val int) bool {
+		return val%2 != 0
+	})
+    fmt.Println(ok) // true
+
+
+	notOk := st.AddIfNotExistBy(4, func(val int) bool {
+		return val%2 != 0
+	})
+    fmt.Println(notOk) // false
+    
+    fmt.Println(st.Values()) // 1, 2, 3
+}
+```
+
+
+### <span id="Delete">Delete</span>
+<p>Delete item in set</p>
+
+<b>Signature:</b>
+
+```go
+func (s Set[T]) Delete(items ...T)
 ```
 <b>Example:</b>
 
@@ -157,12 +252,12 @@ func main() {
 
 
 ### <span id="Contain">Contain</span>
-<p>Check if value is in set or not</p>
+<p>Check if item is in set or not</p>
 
 <b>Signature:</b>
 
 ```go
-func (s Set[T]) Contain(value T) bool
+func (s Set[T]) Contain(item T) bool
 ```
 <b>Example:</b>
 
@@ -309,7 +404,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func (s Set[T]) Iterate(fn func(value T))
+func (s Set[T]) Iterate(fn func(item T))
 ```
 <b>Example:</b>
 
@@ -324,8 +419,8 @@ import (
 func main() {
     set1 := set.NewSet(1, 2, 3)
     arr := []int{}
-    set.Iterate(func(value int) {
+    set.Iterate(func(item int) {
-        arr = append(arr, value)
+        arr = append(arr, item)
     })
 
     fmt.Println(arr) //1,2,3

docs/datastructure/set_zh-CN.md

@@ -22,8 +22,11 @@ import (
 ## 目录
 
 - [NewSet](#NewSet)
+- [NewSetFromSlice](#NewSetFromSlice)
 - [Values](#Values)
 - [Add](#Add)
+- [AddIfNotExist](#AddIfNotExist)
+- [AddIfNotExistBy](#AddIfNotExistBy)
 - [Delete](#Delete)
 - [Contain](#Contain)
 - [ContainAll](#ContainAll)
@@ -34,7 +37,6 @@ import (
 - [IsEmpty](#IsEmpty)
 - [Union](#Union)
 - [Intersection](#Intersection)
-
 - [SymmetricDifference](#SymmetricDifference)
 - [Minus](#Minus)
 
@@ -51,7 +53,7 @@ import (
 
 ```go
 type Set[T comparable] map[T]bool
-func NewSet[T comparable](values ...T) Set[T]
+func NewSet[T comparable](items ...T) Set[T]
 ```
 <b>例子:</b>
 
@@ -71,6 +73,31 @@ func main() {
 
 
 
+### <span id="NewSetFromSlice">NewSetFromSlice</span>
+<p>基于切片创建集合</p>
+
+<b>函数签名:</b>
+
+```go
+func NewSetFromSlice[T comparable](items []T) Set[T]
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSetFromSlice([]int{1, 2, 2, 3})
+    fmt.Println(st.Values()) //1,2,3
+}
+```
+
+
 
 ### <span id="Values">Values</span>
 <p>获取集合中所有元素的切片</p>
@@ -105,7 +132,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (s Set[T]) Add(values ...T)
+func (s Set[T]) Add(items ...T)
 ```
 <b>例子:</b>
 
@@ -126,6 +153,76 @@ func main() {
 ```
 
 
+### <span id="AddIfNotExist">AddIfNotExist</span>
+<p>如果集合中不存在元素，则添加该元素返回true, 如果集合中存在元素, 不做任何操作，返回false</p>
+
+<b>函数签名:</b>
+
+```go
+func (s Set[T]) AddIfNotExist(item T) bool
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSet[int]()
+    st.Add(1, 2, 3)
+
+    r1 := st.AddIfNotExist(1)
+	r2 := st.AddIfNotExist(4)
+
+    fmt.Println(r1) // false
+    fmt.Println(r2) // true
+    fmt.Println(st.Values()) // 1,2,3,4
+}
+```
+
+
+### <span id="AddIfNotExistBy">AddIfNotExistBy</span>
+<p>根据checker函数判断元素是否在集合中，如果集合中不存在元素且checker返回true，则添加该元素返回true, 否则不做任何操作，返回false</p>
+
+<b>函数签名:</b>
+
+```go
+func (s Set[T]) AddIfNotExistBy(item T, checker func(element T) bool) bool
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    set "github.com/duke-git/lancet/v2/datastructure/set"
+)
+
+func main() {
+    st := set.NewSet[int]()
+    st.Add(1, 2)
+
+	ok := st.AddIfNotExistBy(3, func(val int) bool {
+		return val%2 != 0
+	})
+    fmt.Println(ok) // true
+
+
+	notOk := st.AddIfNotExistBy(4, func(val int) bool {
+		return val%2 != 0
+	})
+    fmt.Println(notOk) // false
+    
+    fmt.Println(st.Values()) // 1, 2, 3
+}
+```
+
+
 
 ### <span id="Delete">Delete</span>
 <p>删除集合中元素</p>
@@ -133,7 +230,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (s Set[T]) Delete(values ...T)
+func (s Set[T]) Delete(items ...T)
 ```
 <b>例子:</b>
 
@@ -162,7 +259,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (s Set[T]) Contain(value T) bool
+func (s Set[T]) Contain(item T) bool
 ```
 <b>例子:</b>
 
@@ -309,7 +406,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func (s Set[T]) Iterate(fn func(value T))
+func (s Set[T]) Iterate(fn func(item T))
 ```
 <b>例子:</b>
 
@@ -324,8 +421,8 @@ import (
 func main() {
     set1 := set.NewSet(1, 2, 3)
     arr := []int{}
-    set.Iterate(func(value int) {
+    set.Iterate(func(item int) {
-        arr = append(arr, value)
+        arr = append(arr, item)
     })
 
     fmt.Println(arr) //1,2,3
@@ -420,9 +517,6 @@ func main() {
 ```
 
 
-
-
-
 ### <span id="SymmetricDifference">SymmetricDifference</span>
 <p>返回一个集合，其中元素在第一个集合或第二个集合中，且不同时存在于两个集合中</p>
 

docs/datastructure/tree.md

@@ -29,7 +29,6 @@ import (
 - [PreOrderTraverse](#BSTree_PreOrderTraverse)
 - [InOrderTraverse](#BSTree_InOrderTraverse)
 - [PostOrderTraverse](#BSTree_PostOrderTraverse)
-  
 - [LevelOrderTraverse](#BSTree_LevelOrderTraverse)
 - [Depth](#BSTree_Depth)
 - [HasSubTree](#BSTree_HasSubTree)

docs/datastructure/tree_zh-CN.md

@@ -29,7 +29,6 @@ import (
 - [PreOrderTraverse](#BSTree_PreOrderTraverse)
 - [InOrderTraverse](#BSTree_InOrderTraverse)
 - [PostOrderTraverse](#BSTree_PostOrderTraverse)
-  
 - [LevelOrderTraverse](#BSTree_LevelOrderTraverse)
 - [Depth](#BSTree_Depth)
 - [HasSubTree](#BSTree_HasSubTree)

docs/datetime.md

@@ -42,7 +42,6 @@ import (
 - [GetNightTimestamp](#GetNightTimestamp)
 - [FormatTimeToStr](#FormatTimeToStr)
 - [FormatStrToTime](#FormatStrToTime)
-
 - [NewUnixNow](#NewUnixNow)
 - [NewUnix](#NewUnix)
 - [NewFormat](#NewFormat)
@@ -251,7 +250,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func BeginOfWeek(t time.Time) time.Time
+func BeginOfWeek(t time.Time, beginFrom ...time.Weekday) time.Time
 ```
 <b>Example:</b>
 
@@ -414,7 +413,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func EndOfWeek(t time.Time) time.Time
+func EndOfWeek(t time.Time, endWith ...time.Weekday) time.Time
 ```
 <b>Example:</b>
 

docs/datetime_zh-CN.md

@@ -41,7 +41,6 @@ import (
 - [GetNightTimestamp](#GetNightTimestamp)
 - [FormatTimeToStr](#FormatTimeToStr)
 - [FormatStrToTime](#FormatStrToTime)
-
 - [NewUnixNow](#NewUnixNow)
 - [NewUnix](#NewUnix)
 - [NewFormat](#NewFormat)
@@ -243,12 +242,12 @@ func main() {
 
 
 ### <span id="BeginOfWeek">BeginOfWeek</span>
-<p>返回指定时间的星期开始时间</p>
+<p>返回指定时间的每周开始时间,默认开始时间星期日</p>
 
 <b>函数签名:</b>
 
 ```go
-func BeginOfWeek(t time.Time) time.Time
+func BeginOfWeek(t time.Time, beginFrom ...time.Weekday) time.Time
 ```
 <b>例子:</b>
 
@@ -406,12 +405,12 @@ func main() {
 
 
 ### <span id="EndOfWeek">EndOfWeek</span>
-<p>返回指定时间的星期结束时间</p>
+<p>返回指定时间的星期结束时间,默认结束时间星期六</p>
 
 <b>函数签名:</b>
 
 ```go
-func EndOfWeek(t time.Time) time.Time
+func EndOfWeek(t time.Time, endWith ...time.Weekday) time.Time
 ```
 <b>例子:</b>
 

docs/fileutil.md

@@ -28,7 +28,6 @@ import (
 - [IsExist](#IsExist)
 - [IsLink](#IsLink)
 - [IsDir](#IsDir)
-
 - [ListFileNames](#ListFileNames)
 - [RemoveFile](#RemoveFile)
 - [ReadFileToString](#ReadFileToString)

docs/fileutil_zh-CN.md

@@ -28,7 +28,6 @@ import (
 - [IsExist](#IsExist)
 - [IsLink](#IsLink)
 - [IsDir](#IsDir)
-
 - [ListFileNames](#ListFileNames)
 - [RemoveFile](#RemoveFile)
 - [ReadFileToString](#ReadFileToString)
@@ -120,7 +119,7 @@ func main() {
 
 
 ### <span id="CopyFile">CopyFile</span>
-<p>拷贝文件，会覆盖原有的拷贝文件</p>
+<p>拷贝文件，会覆盖原有的文件</p>
 
 <b>函数签名:</b>
 
@@ -262,7 +261,7 @@ func main() {
 
 
 ### <span id="IsDir">IsDir</span>
-<p>判断目录是否存在</p>
+<p>判断参数是否是目录</p>
 
 <b>函数签名:</b>
 

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.
+<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>
-Param should be number or numberic 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/function.md

@@ -22,10 +22,11 @@ import (
 ## Index
 - [After](#After)
 - [Before](#Before)
-- [Curry](#Curry)
+- [CurryFn](#CurryFn)
 - [Compose](#Compose)
 - [Debounced](#Debounced)
 - [Delay](#Delay)
+- [Pipeline](#Pipeline)
 - [Watcher](#Watcher)
 
 <div STYLE="page-break-after: always;"></div>
@@ -124,15 +125,15 @@ func main() {
 
 
 
-### <span id="Curry">Curry</span>
+### <span id="CurryFn">CurryFn</span>
 
-<p>Make a curry function.</p>
+<p>Make curry function.</p>
 
 <b>Signature:</b>
 
 ```go
-type Fn func(...any) any
+type CurryFn[T any] func(...T) T
-func (f Fn) Curry(i any) func(...any) any
+func (cf CurryFn[T]) New(val T) func(...T) T
 ```
 <b>Example:</b>
 
@@ -148,12 +149,15 @@ func main() {
     add := func(a, b int) int {
 		return a + b
 	}
-	var addCurry function.Fn = func(values ...any) any {
+
-		return add(values[0].(int), values[1].(int))
+	var addCurry CurryFn[int] = func(values ...int) int {
+		return add(values[0], values[1])
 	}
-	add1 := addCurry.Curry(1)
+	add1 := addCurry.New(1)
+
 	result := add1(2)
-    fmt.Println(result) //3
+
+	fmt.Println(result) //3
 }
 ```
 
@@ -166,7 +170,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func Compose(fnList ...func(...any) any) func(...any) any
+func Compose[T any](fnList ...func(...T) T) func(...T) T
 ```
 <b>Example:</b>
 
@@ -179,17 +183,17 @@ import (
 )
 
 func main() {
-    add1 := func(v ...any) any {
+   	toUpper := func(strs ...string) string {
-		return v[0].(int) + 1
+		return strings.ToUpper(strs[0])
 	}
-    add2 := func(v ...any) any {
+	toLower := func(strs ...string) string {
-		return v[0].(int) + 2
+		return strings.ToLower(strs[0])
 	}
+	transform := Compose(toUpper, toLower)
 
-    add3 := function.Compose(add1, add2)
+	result := transform("aBCde")
-	result := add3(1)
 
-    fmt.Println(result) //4
+	fmt.Println(result) //ABCDE
 }
 ```
 
@@ -258,9 +262,9 @@ import (
 
 func main() {
 	var print = func(s string) {
-		fmt.Println(count) //test delay
+		fmt.Println(count) //delay 2 seconds
 	}
-	function.Delay(2*time.Second, print, "test delay")
+	function.Delay(2*time.Second, print, "delay 2 seconds")
 }
 ```
 
@@ -300,6 +304,43 @@ func main() {
 ```
 
 
+### <span id="Pipeline">Pipeline</span>
+
+<p>Pipeline takes a list of functions and returns a function whose param will be passed into
+the functions one by one.</p>
+
+<b>Signature:</b>
+
+```go
+func Pipeline[T any](funcs ...func(T) T) func(T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/function"
+)
+
+func main() {
+    addOne := func(x int) int {
+		return x + 1
+	}
+	double := func(x int) int {
+		return 2 * x
+	}
+	square := func(x int) int {
+		return x * x
+	}
+
+	fn := Pipeline(addOne, double, square)
+
+	fmt.Println(fn(2)) //36
+}
+```
+
 
 ### <span id="Watcher">Watcher</span>
 
@@ -313,6 +354,7 @@ type Watcher struct {
 	stopTime  int64
 	excuting  bool
 }
+func NewWatcher() *Watcher
 func (w *Watcher) Start() //start the watcher
 func (w *Watcher) Stop() //stop the watcher
 func (w *Watcher) Reset() //reset the watcher
@@ -329,7 +371,8 @@ import (
 )
 
 func main() {
-    w := &function.Watcher{}
+   	w := function.NewWatcher()
+
 	w.Start()
 
 	longRunningTask()
@@ -339,14 +382,10 @@ func main() {
 	w.Stop()
 
 	eapsedTime := w.GetElapsedTime().Milliseconds()
+	
 	fmt.Println(eapsedTime)
 
 	w.Reset()
-
-	fmt.Println(w.excuting) //false
-
-	fmt.Println(w.startTime) //0
-	fmt.Println(w.stopTime) //0
 }
 
 func longRunningTask() {

docs/function_zh-CN.md

@@ -22,10 +22,11 @@ import (
 ## 目录
 - [After](#After)
 - [Before](#Before)
-- [Curry](#Curry)
+- [CurryFn](#CurryFn)
 - [Compose](#Compose)
 - [Debounced](#Debounced)
 - [Delay](#Delay)
+- [Pipeline](#Pipeline)
 - [Watcher](#Watcher)
 
 <div STYLE="page-break-after: always;"></div>
@@ -123,15 +124,15 @@ func main() {
 
 
 
-### <span id="Curry">Curry</span>
+### <span id="CurryFn">CurryFn</span>
 
-<p>创建一个柯里化的函数</p>
+<p>创建柯里化函数</p>
 
 <b>函数签名:</b>
 
 ```go
-type Fn func(...any) any
+type CurryFn[T any] func(...T) T
-func (f Fn) Curry(i any) func(...any) any
+func (cf CurryFn[T]) New(val T) func(...T) T
 ```
 <b>例子:</b>
 
@@ -147,11 +148,14 @@ func main() {
 	add := func(a, b int) int {
 		return a + b
 	}
-	var addCurry function.Fn = func(values ...any) any {
+
-		return add(values[0].(int), values[1].(int))
+	var addCurry CurryFn[int] = func(values ...int) int {
+		return add(values[0], values[1])
 	}
-	add1 := addCurry.Curry(1)
+	add1 := addCurry.New(1)
+
 	result := add1(2)
+
 	fmt.Println(result) //3
 }
 ```
@@ -160,12 +164,12 @@ func main() {
 
 ### <span id="Compose">Compose</span>
 
-<p>从右至左组合函数列表fnList， 返回组合后的函数</p>
+<p>从右至左组合函数列表fnList，返回组合后的函数</p>
 
 <b>函数签名:</b>
 
 ```go
-func Compose(fnList ...func(...any) any) func(...any) any
+func Compose[T any](fnList ...func(...T) T) func(...T) T
 ```
 <b>例子:</b>
 
@@ -178,17 +182,17 @@ import (
 )
 
 func main() {
-	add1 := func(v ...any) any {
+	toUpper := func(strs ...string) string {
-		return v[0].(int) + 1
+		return strings.ToUpper(strs[0])
 	}
-	add2 := func(v ...any) any {
+	toLower := func(strs ...string) string {
-		return v[0].(int) + 2
+		return strings.ToLower(strs[0])
 	}
+	transform := Compose(toUpper, toLower)
 
-	add3 := function.Compose(add1, add2)
+	result := transform("aBCde")
-	result := add3(1)
 
-	fmt.Println(result) //4
+	fmt.Println(result) //ABCDE
 }
 ```
 
@@ -196,7 +200,7 @@ func main() {
 
 ### <span id="Debounced">Debounced</span>
 
-<p>创建一个 debounced 函数，该函数延迟调用 fn 直到自上次调用 debounced 函数后等待持续时间过去。</p>
+<p>创建一个debounced函数，该函数延迟调用fn直到自上次调用debounced函数后等待持续时间过去。</p>
 
 <b>函数签名:</b>
 
@@ -300,9 +304,47 @@ func main() {
 
 
 
+### <span id="Pipeline">Pipeline</span>
+
+<p>执行函数pipeline.</p>
+
+<b>函数签名:</b>
+
+```go
+func Pipeline[T any](funcs ...func(T) T) func(T) T
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/function"
+)
+
+func main() {
+    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)
+
+	fmt.Println(fn(2)) //36
+}
+```
+
+
+
 ### <span id="Watcher">Watcher</span>
 
-<p>Watcher 用于记录代码执行时间。可以启动/停止/重置手表定时器。获取函数执行的时间。 </p>
+<p>Watcher用于记录代码执行时间。可以启动/停止/重置手表定时器。获取函数执行的时间。</p>
 
 <b>函数签名:</b>
 
@@ -312,6 +354,7 @@ type Watcher struct {
 	stopTime  int64
 	excuting  bool
 }
+func NewWatcher() *Watcher
 func (w *Watcher) Start() //start the watcher
 func (w *Watcher) Stop() //stop the watcher
 func (w *Watcher) Reset() //reset the watcher
@@ -328,7 +371,8 @@ import (
 )
 
 func main() {
-    w := &function.Watcher{}
+    w := function.NewWatcher()
+
 	w.Start()
 
 	longRunningTask()
@@ -338,14 +382,11 @@ func main() {
 	w.Stop()
 
 	eapsedTime := w.GetElapsedTime().Milliseconds()
+	
 	fmt.Println(eapsedTime)
 
 	w.Reset()
 
-	fmt.Println(w.excuting) //false
-
-	fmt.Println(w.startTime) //0
-	fmt.Println(w.stopTime) //0
 }
 
 func longRunningTask() {

docs/mathutil.md

@@ -28,7 +28,6 @@ import (
 - [MaxBy](#MaxBy)
 - [Min](#Min)
 - [MinBy](#MaxBy)
-
 - [Percent](#Percent)
 - [RoundToFloat](#RoundToFloat)
 - [RoundToString](#RoundToString)
@@ -46,7 +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>
 
@@ -158,7 +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>
 
@@ -219,12 +218,12 @@ func main() {
 
 
 ### <span id="Min">Min</span>
-<p>Return min value of numbers.</p>
+<p>Return the minimum value of numbers.</p>
 
 <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>
 
@@ -303,8 +302,8 @@ import (
 )
 
 func main() {
-	fmt.Println(mathutil.Percent(1, 2, 2)) //1
+	fmt.Println(mathutil.Percent(1, 2, 2)) //0.5
-	fmt.Println(mathutil.Percent(0.1, 0.3, 2)) //33.33
+	fmt.Println(mathutil.Percent(0.1, 0.3, 2)) //0.33
 }
 ```
 

docs/mathutil_zh-CN.md

@@ -28,7 +28,6 @@ import (
 - [MaxBy](#MaxBy)
 - [Min](#Min)
 - [MinBy](#MaxBy)
-  
 - [Percent](#Percent)
 - [RoundToFloat](#RoundToFloat)
 - [RoundToString](#RoundToString)
@@ -45,7 +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>
 
@@ -155,7 +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>
 
@@ -221,7 +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>
 
@@ -300,8 +299,8 @@ import (
 )
 
 func main() {
-	fmt.Println(mathutil.Percent(1, 2, 2)) //1
+	fmt.Println(mathutil.Percent(1, 2, 2)) //0.5
-	fmt.Println(mathutil.Percent(0.1, 0.3, 2)) //33.33
+	fmt.Println(mathutil.Percent(0.1, 0.3, 2)) //0.33
 }
 ```
 

docs/netutil.md

@@ -25,7 +25,6 @@ import (
 ## Index
 - [ConvertMapToQueryString](#ConvertMapToQueryString)
 - [EncodeUrl](#EncodeUrl)
-  
 - [GetInternalIp](#GetInternalIp)
 - [GetIps](#GetIps)
 - [GetMacAddrs](#GetMacAddrs)
@@ -38,7 +37,6 @@ import (
 - [SendRequest](#SendRequest)
 - [DecodeResponse](#DecodeResponse)
 - [StructToUrlValues](#StructToUrlValues)
-
 - [HttpGet<sup>Deprecated</sup>](#HttpGet)
 - [HttpDelete<sup>Deprecated</sup>](#HttpDelete)
 - [HttpPost<sup>Deprecated</sup>](#HttpPost)

docs/netutil_zh-CN.md

@@ -30,7 +30,6 @@ import (
 - [GetMacAddrs](#GetMacAddrs)
 - [GetPublicIpInfo](#GetPublicIpInfo)
 - [GetRequestPublicIp](#GetRequestPublicIp)
-
 - [IsPublicIP](#IsPublicIP)
 - [IsInternalIP](#IsInternalIP)
 - [HttpRequest](#HttpRequest)
@@ -38,13 +37,11 @@ import (
 - [SendRequest](#SendRequest)
 - [DecodeResponse](#DecodeResponse)
 - [StructToUrlValues](#StructToUrlValues)
-
 - [HttpGet<sup>Deprecated</sup>](#HttpGet)
 - [HttpDelete<sup>Deprecated</sup>](#HttpDelete)
 - [HttpPost<sup>Deprecated</sup>](#HttpPost)
 - [HttpPut<sup>Deprecated</sup>](#HttpPut)
 - [HttpPatch<sup>Deprecated</sup>](#HttpPatch)
-
 - [ParseHttpResponse](#ParseHttpResponse)
 
 <div STYLE="page-break-after: always;"></div>

docs/random.md

@@ -1,16 +1,17 @@
 # Random
+
 Package random implements some basic functions to generate random int and string.
 
 <div STYLE="page-break-after: always;"></div>
 
 ## Source:
 
-- [https://github.com/duke-git/lancet/blob/main/random/random.go](https://github.com/duke-git/lancet/blob/main/random/random.go)
+-   [https://github.com/duke-git/lancet/blob/main/random/random.go](https://github.com/duke-git/lancet/blob/main/random/random.go)
-
 
 <div STYLE="page-break-after: always;"></div>
 
 ## Usage:
+
 ```go
 import (
     "github.com/duke-git/lancet/v2/random"
@@ -20,17 +21,22 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## Index
-- [RandBytes](#RandBytes)
+
-- [RandInt](#RandInt)
+-   [RandBytes](#RandBytes)
-- [RandString](#RandString)
+-   [RandInt](#RandInt)
-- [UUIdV4](#UUIdV4)
+-   [RandString](#RandString)
+-   [RandUpper](#RandUpper)
+-   [RandLower](#RandLower)
+-   [RandNumeral](#RandNumeral)
+-   [RandNumeralOrLetter](#RandNumeralOrLetter)
+-   [UUIdV4](#UUIdV4)
 
 <div STYLE="page-break-after: always;"></div>
 
 ## Documentation
 
-
 ### <span id="RandBytes">RandBytes</span>
+
 <p>Generate random byte slice.</p>
 
 <b>Signature:</b>
@@ -38,6 +44,7 @@ import (
 ```go
 func RandBytes(length int) []byte
 ```
+
 <b>Example:</b>
 
 ```go
@@ -54,8 +61,8 @@ func main() {
 }
 ```
 
-
 ### <span id="RandInt">RandInt</span>
+
 <p>Generate random int between min and max, may contain min, not max.</p>
 
 <b>Signature:</b>
@@ -63,6 +70,7 @@ func main() {
 ```go
 func RandInt(min, max int) int
 ```
+
 <b>Example:</b>
 
 ```go
@@ -79,16 +87,16 @@ func main() {
 }
 ```
 
+### <span id="RandString">RandString</span>
 
-
+<p>Generate random given length string. only contains letter (a-zA-Z)</p>
-### <span id="RandString">RandInt</span>
-<p>Generate random given length string.</p>
 
 <b>Signature:</b>
 
 ```go
 func RandString(length int) string
 ```
+
 <b>Example:</b>
 
 ```go
@@ -101,14 +109,116 @@ import (
 
 func main() {
 	randStr := random.RandString(6)
-	fmt.Println(randStr)
+	fmt.Println(randStr) //pGWsze
 }
 ```
 
+### <span id="RandUpper">RandUpper</span>
 
+<p>Generate a random upper case string</p>
 
+<b>Signature:</b>
+
+```go
+func RandUpper(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandString(6)
+	fmt.Println(randStr) //PACWGF
+}
+```
+
+### <span id="RandLower">RandLower</span>
+
+<p>Generate a random lower case string</p>
+
+<b>Signature:</b>
+
+```go
+func RandLower(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandLower(6)
+	fmt.Println(randStr) //siqbew
+}
+```
+
+### <span id="RandNumeral">RandNumeral</span>
+
+<p>Generate a random numeral string</p>
+
+<b>Signature:</b>
+
+```go
+func RandNumeral(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandNumeral(6)
+	fmt.Println(randStr) //035172
+}
+```
+
+### <span id="RandNumeralOrLetter">RandNumeralOrLetter</span>
+
+<p>generate a random numeral or letter string</p>
+
+<b>Signature:</b>
+
+```go
+func RandNumeralOrLetter(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandNumeralOrLetter(6)
+	fmt.Println(randStr) //0aW7cQ
+}
+```
 
 ### <span id="UUIdV4">UUIdV4</span>
+
 <p>Generate a random UUID of version 4 according to RFC 4122.</p>
 
 <b>Signature:</b>
@@ -116,6 +226,7 @@ func main() {
 ```go
 func UUIdV4() (string, error)
 ```
+
 <b>Example:</b>
 
 ```go
@@ -134,5 +245,3 @@ func main() {
 	fmt.Println(uuid)
 }
 ```
-
-

docs/random_zh-CN.md

@@ -1,16 +1,17 @@
 # Random
-random随机数生成器包，可以生成随机[]bytes, int, string。
+
+random 随机数生成器包，可以生成随机[]bytes, int, string。
 
 <div STYLE="page-break-after: always;"></div>
 
 ## 源码:
 
-- [https://github.com/duke-git/lancet/blob/main/random/random.go](https://github.com/duke-git/lancet/blob/main/random/random.go)
+-   [https://github.com/duke-git/lancet/blob/main/random/random.go](https://github.com/duke-git/lancet/blob/main/random/random.go)
-
 
 <div STYLE="page-break-after: always;"></div>
 
 ## 用法:
+
 ```go
 import (
     "github.com/duke-git/lancet/v2/random"
@@ -20,18 +21,22 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## 目录
-- [RandBytes](#RandBytes)
-- [RandInt](#RandInt)
-- [RandString](#RandString)
-- [UUIdV4](#UUIdV4)
 
+-   [RandBytes](#RandBytes)
+-   [RandInt](#RandInt)
+-   [RandString](#RandString)
+-   [RandUpper](#RandUpper)
+-   [RandLower](#RandLower)
+-   [RandNumeral](#RandNumeral)
+-   [RandNumeralOrLetter](#RandNumeralOrLetter)
+-   [UUIdV4](#UUIdV4)
 
 <div STYLE="page-break-after: always;"></div>
 
 ## 文档
 
-
 ### <span id="RandBytes">RandBytes</span>
+
 <p>生成随机字节切片</p>
 
 <b>函数签名:</b>
@@ -39,6 +44,7 @@ import (
 ```go
 func RandBytes(length int) []byte
 ```
+
 <b>例子:</b>
 
 ```go
@@ -55,8 +61,8 @@ func main() {
 }
 ```
 
-
 ### <span id="RandInt">RandInt</span>
+
 <p>生成随机int, 范围[min, max)</p>
 
 <b>函数签名:</b>
@@ -64,6 +70,7 @@ func main() {
 ```go
 func RandInt(min, max int) int
 ```
+
 <b>例子:</b>
 
 ```go
@@ -80,16 +87,16 @@ func main() {
 }
 ```
 
+### <span id="RandString">RandString</span>
 
-
+<p>生成给定长度的随机字符串，只包含字母(a-zA-Z)</p>
-### <span id="RandString">RandInt</span>
-<p>生成随机给定长度的随机字符串</p>
 
 <b>函数签名:</b>
 
 ```go
 func RandString(length int) string
 ```
+
 <b>例子:</b>
 
 ```go
@@ -102,13 +109,116 @@ import (
 
 func main() {
 	randStr := random.RandString(6)
-	fmt.Println(randStr)
+	fmt.Println(randStr) //pGWsze
 }
 ```
 
+### <span id="RandUpper">RandUpper</span>
 
+<p>生成给定长度的随机大写字母字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandUpper(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandString(6)
+	fmt.Println(randStr) //PACWGF
+}
+```
+
+### <span id="RandLower">RandLower</span>
+
+<p>生成给定长度的随机小写字母字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandLower(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandLower(6)
+	fmt.Println(randStr) //siqbew
+}
+```
+
+### <span id="RandNumeral">RandNumeral</span>
+
+<p>生成给定长度的随机数字字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandNumeral(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandNumeral(6)
+	fmt.Println(randStr) //035172
+}
+```
+
+### <span id="RandNumeralOrLetter">RandNumeralOrLetter</span>
+
+<p>生成给定长度的随机字符串（数字+字母)</p>
+
+<b>函数签名:</b>
+
+```go
+func RandNumeralOrLetter(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+	randStr := random.RandNumeralOrLetter(6)
+	fmt.Println(randStr) //0aW7cQ
+}
+```
 
 ### <span id="UUIdV4">UUIdV4</span>
+
 <p>生成UUID v4字符串</p>
 
 <b>函数签名:</b>
@@ -116,6 +226,7 @@ func main() {
 ```go
 func UUIdV4() (string, error)
 ```
+
 <b>例子:</b>
 
 ```go
@@ -134,5 +245,3 @@ func main() {
 	fmt.Println(uuid)
 }
 ```
-
-

docs/strutil.md

@@ -28,15 +28,17 @@ import (
 - [Capitalize](#Capitalize)
 - [IsString](#IsString)
 - [KebabCase](#KebabCase)
+- [UpperKebabCase](#UpperKebabCase)
 - [LowerFirst](#LowerFirst)
 - [UpperFirst](#UpperFirst)
 - [PadEnd](#PadEnd)
 - [PadStart](#PadStart)
 - [Reverse](#Reverse)
 - [SnakeCase](#SnakeCase)
+- [UpperSnakeCase](#UpperSnakeCase)
 - [SplitEx](#SplitEx)
+- [Substring](#Substring)
 - [Wrap](#Wrap)
-  
 - [Unwrap](#Unwrap)
   
 
@@ -46,7 +48,7 @@ import (
 
 
 ### <span id="After">After</span>
-<p>Creates substring in source string after position when char first appear.</p>
+<p>Returns the substring after the first occurrence of a specified string in the source string.</p>
 
 <b>Signature:</b>
 
@@ -76,7 +78,7 @@ func main() {
 
 
 ### <span id="AfterLast">AfterLast</span>
-<p>Creates substring in source string after position when char last appear.</p>
+<p>Returns the substring after the last occurrence of a specified string in the source string.</p>
 
 <b>Signature:</b>
 
@@ -107,7 +109,7 @@ func main() {
 
 
 ### <span id="Before">Before</span>
-<p>Creates substring in source string before position when char first appear.</p>
+<p>Returns the substring of the source string up to the first occurrence of the specified string.</p>
 
 <b>Signature:</b>
 
@@ -138,7 +140,7 @@ func main() {
 
 
 ### <span id="BeforeLast">BeforeLast</span>
-<p>Creates substring in source string before position when char first appear.</p>
+<p>Returns the substring of the source string up to the last occurrence of the specified string.</p>
 
 <b>Signature:</b>
 
@@ -166,10 +168,8 @@ func main() {
 ```
 
 
-
-
 ### <span id="CamelCase">CamelCase</span>
-<p>Covert string to camelCase string.</p>
+<p>Coverts string to camelCase string, non letters and numbers will be ignored.</p>
 
 <b>Signature:</b>
 
@@ -196,6 +196,75 @@ func main() {
 
 	s4 := strutil.CamelCase("foo bar")
 	fmt.Println(s4) //fooBar
+
+	s4 := strutil.CamelCase("Foo-#1😄$_%^&*(1bar")
+	fmt.Println(s4) //foo11Bar
+
+}
+```
+
+
+### <span id="KebabCase">KebabCase</span>
+<p>KebabCase covert string to kebab-case, non letters and numbers will be ignored.</p>
+
+<b>Signature:</b>
+
+```go
+func KebabCase(s string) string
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	s1 := strutil.KebabCase("Foo Bar-")
+	fmt.Println(s1) //foo-bar
+
+	s2 := strutil.KebabCase("foo_Bar")
+	fmt.Println(s2) //foo-bar
+
+	s3 := strutil.KebabCase("fooBar")
+	fmt.Println(s3) //foo-bar
+
+	s4 := strutil.KebabCase("__FOO_BAR__")
+	fmt.Println(s4) //foo-bar
+}
+```
+
+
+
+### <span id="UpperKebabCase">UpperKebabCase</span>
+<p>UpperKebabCase covert string to upper KEBAB-CASE, non letters and numbers will be ignored.</p>
+
+<b>Signature:</b>
+
+```go
+func KebabCase(s string) string
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	s1 := strutil.UpperKebabCase("Foo Bar-")
+	fmt.Println(s1) //FOO-BAR
+
+	s2 := strutil.UpperKebabCase("foo_Bar")
+	fmt.Println(s2) //FOO-BAR
+
+	s3 := strutil.UpperKebabCase("fooBar")
+	fmt.Println(s3) //FOO-BAR
+
+	s4 := strutil.UpperKebabCase("__FOO_BAR__")
+	fmt.Println(s4) //FOO-BAR
 }
 ```
 
@@ -458,7 +527,7 @@ func main() {
 
 
 ### <span id="SnakeCase">SnakeCase</span>
-<p>Covert string to snake_case.</p>
+<p>Coverts string to snake_case, non letters and numbers will be ignored.</p>
 
 <b>Signature:</b>
 
@@ -484,14 +553,47 @@ func main() {
 	fmt.Println(s3) //foo_bar
 
 	s4 := strutil.SnakeCase("__FOO_BAR__")
-	fmt.Println(s4) //f_o_o_b_a_r
+	fmt.Println(s4) //foo_bar
 
-	s5 := strutil.SnakeCase("aBbc-s$@a&%_B.B^C")
+	s5 := strutil.SnakeCase("Foo-#1😄$_%^&*(1bar")
-	fmt.Println(s5) //a_bbc_s_a_b_b_c
+	fmt.Println(s5) //foo_1_1_bar
 }
 ```
 
 
+### <span id="UpperSnakeCase">UpperSnakeCase</span>
+<p>Coverts string to upper KEBAB-CASE, non letters and numbers will be ignored.</p>
+
+<b>Signature:</b>
+
+```go
+func SnakeCase(s string) string
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	s1 := strutil.UpperSnakeCase("Foo Bar-")
+	fmt.Println(s1) //FOO_BAR
+
+	s2 := strutil.UpperSnakeCase("foo_Bar")
+	fmt.Println(s2) //FOO_BAR
+
+	s3 := strutil.UpperSnakeCase("fooBar")
+	fmt.Println(s3) //FOO_BAR
+
+	s4 := strutil.UpperSnakeCase("__FOO_BAR__")
+	fmt.Println(s4) //FOO_BAR
+
+	s5 := strutil.UpperSnakeCase("Foo-#1😄$_%^&*(1bar")
+	fmt.Println(s5) //FOO_1_1_BAR
+}
+```
 
 
 ### <span id="SplitEx">SplitEx</span>
@@ -530,9 +632,45 @@ func main() {
 
 
 
+### <span id="Substring">Substring</span>
+<p>Returns a substring of the specified length starting at the specified offset position.</p>
+
+<b>Signature:</b>
+
+```go
+func Substring(s string, offset int, length uint) string
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	result1 := strutil.Substring("abcde", 1, 3)
+	fmt.Println(result1) //bcd
+
+	result2 := strutil.Substring("abcde", 1, 5)
+	fmt.Println(result2) //bcde
+
+	result3 := strutil.Substring("abcde", -1, 3)
+	fmt.Println(result3) //e
+
+	result4 := strutil.Substring("abcde", -2, 2)
+	fmt.Println(result4) //de
+
+	result5 := strutil.Substring("abcde", -2, 3)
+	fmt.Println(result5) //de
+
+	result6 := strutil.Substring("你好，欢迎你", 0, 2)
+	fmt.Println(result6) //你好
+}
+```
 
 ### <span id="Wrap">Wrap</span>
-<p>Wrap a string with another string.</p>
+<p>Wrap a string with given string.</p>
 
 <b>Signature:</b>
 
@@ -569,7 +707,7 @@ func main() {
 
 
 ### <span id="Wrap">Wrap</span>
-<p>Unwrap a given string from anther string. will change str value.</p>
+<p>Unwrap a given string from anther string. will change source string.</p>
 
 <b>Signature:</b>
 

docs/strutil_zh-CN.md

@@ -28,15 +28,17 @@ import (
 - [Capitalize](#Capitalize)
 - [IsString](#IsString)
 - [KebabCase](#KebabCase)
+- [UpperKebabCase](#UpperKebabCase)
 - [LowerFirst](#LowerFirst)
 - [UpperFirst](#UpperFirst)
 - [PadEnd](#PadEnd)
 - [PadStart](#PadStart)
 - [Reverse](#Reverse)
 - [SnakeCase](#SnakeCase)
+- [UpperSnakeCase](#UpperSnakeCase)
 - [SplitEx](#SplitEx)
+- [Substring](#Substring)
 - [Wrap](#Wrap)
-  
 - [Unwrap](#Unwrap)
   
 
@@ -47,7 +49,7 @@ import (
 
 
 ### <span id="After">After</span>
-<p>截取源字符串中char首次出现时的位置之后的子字符串</p>
+<p>返回源字符串中特定字符串首次出现时的位置之后的子字符串</p>
 
 <b>函数签名:</b>
 
@@ -77,7 +79,7 @@ func main() {
 
 
 ### <span id="AfterLast">AfterLast</span>
-<p>截取源字符串中char最后一次出现时的位置之后的子字符串</p>
+<p>返回源字符串中指定字符串最后一次出现时的位置之后的子字符串</p>
 
 <b>函数签名:</b>
 
@@ -108,7 +110,7 @@ func main() {
 
 
 ### <span id="Before">Before</span>
-<p>截取源字符串中char首次出现时的位置之前的子字符串</p>
+<p>返回源字符串中指定字符串第一次出现时的位置之前的子字符串</p>
 
 <b>函数签名:</b>
 
@@ -139,7 +141,7 @@ func main() {
 
 
 ### <span id="BeforeLast">BeforeLast</span>
-<p>截取源字符串中char最后一次出现时的位置之前的子字符串</p>
+<p>返回源字符串中指定字符串最后一次出现时的位置之前的子字符串</p>
 
 <b>函数签名:</b>
 
@@ -170,7 +172,7 @@ func main() {
 
 
 ### <span id="CamelCase">CamelCase</span>
-<p>将字符串转换为驼峰式字符串</p>
+<p>将字符串转换为驼峰式字符串, 非字母和数字会被忽略</p>
 
 <b>函数签名:</b>
 
@@ -197,6 +199,9 @@ func main() {
 
 	s4 := strutil.CamelCase("foo bar")
 	fmt.Println(s4) //fooBar
+
+	s4 := strutil.CamelCase("Foo-#1😄$_%^&*(1bar")
+	fmt.Println(s4) //foo11Bar
 }
 ```
 
@@ -234,7 +239,7 @@ func main() {
 
 
 ### <span id="IsString">IsString</span>
-<p>检查值的数据类型是否为字符串</p>
+<p>判断传入参数的数据类型是否为字符串</p>
 
 <b>函数签名:</b>
 
@@ -262,7 +267,7 @@ func main() {
 
 
 ### <span id="KebabCase">KebabCase</span>
-<p>将字符串转换为kebab-case</p>
+<p>将字符串转换为kebab-case, 非字母和数字会被忽略</p>
 
 <b>函数签名:</b>
 
@@ -288,7 +293,40 @@ func main() {
 	fmt.Println(s3) //foo-bar
 
 	s4 := strutil.KebabCase("__FOO_BAR__")
-	fmt.Println(s4) //f-o-o-b-a-r
+	fmt.Println(s4) //foo-bar
+}
+```
+
+
+
+### <span id="UpperKebabCase">UpperKebabCase</span>
+<p>将字符串转换为大写KEBAB-CASE, 非字母和数字会被忽略</p>
+
+<b>函数签名:</b>
+
+```go
+func KebabCase(s string) string
+```
+<b>例子:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	s1 := strutil.UpperKebabCase("Foo Bar-")
+	fmt.Println(s1) //FOO-BAR
+
+	s2 := strutil.UpperKebabCase("foo_Bar")
+	fmt.Println(s2) //FOO-BAR
+
+	s3 := strutil.UpperKebabCase("fooBar")
+	fmt.Println(s3) //FOO-BAR
+
+	s4 := strutil.UpperKebabCase("__FOO_BAR__")
+	fmt.Println(s4) //FOO-BAR
 }
 ```
 
@@ -330,7 +368,7 @@ func main() {
 
 
 ### <span id="UpperFirst">UpperFirst</span>
-<p>将字符串的第一个字符转换为大写</p>
+<p>将字符串的第一个字符转换为大写形式</p>
 
 <b>函数签名:</b>
 
@@ -459,7 +497,7 @@ func main() {
 
 
 ### <span id="SnakeCase">SnakeCase</span>
-<p>将字符串转换为snake_case形式</p>
+<p>将字符串转换为snake_case形式, 非字母和数字会被忽略</p>
 
 <b>函数签名:</b>
 
@@ -485,10 +523,45 @@ func main() {
 	fmt.Println(s3) //foo_bar
 
 	s4 := strutil.SnakeCase("__FOO_BAR__")
-	fmt.Println(s4) //f_o_o_b_a_r
+	fmt.Println(s4) //foo_bar
 
-	s5 := strutil.SnakeCase("aBbc-s$@a&%_B.B^C")
+	s5 := strutil.SnakeCase("Foo-#1😄$_%^&*(1bar")
-	fmt.Println(s5) //a_bbc_s_a_b_b_c
+	fmt.Println(s5) //foo_1_1_bar
+}
+```
+
+
+### <span id="UpperSnakeCase">UpperSnakeCase</span>
+<p>将字符串转换为大写SNAKE_CASE形式, 非字母和数字会被忽略</p>
+
+<b>函数签名:</b>
+
+```go
+func SnakeCase(s string) string
+```
+<b>例子:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	s1 := strutil.UpperSnakeCase("Foo Bar-")
+	fmt.Println(s1) //FOO_BAR
+
+	s2 := strutil.UpperSnakeCase("foo_Bar")
+	fmt.Println(s2) //FOO_BAR
+
+	s3 := strutil.UpperSnakeCase("fooBar")
+	fmt.Println(s3) //FOO_BAR
+
+	s4 := strutil.UpperSnakeCase("__FOO_BAR__")
+	fmt.Println(s4) //FOO_BAR
+
+	s5 := strutil.UpperSnakeCase("Foo-#1😄$_%^&*(1bar")
+	fmt.Println(s5) //FOO_1_1_BAR
 }
 ```
 
@@ -528,6 +601,42 @@ func main() {
 }
 ```
 
+### <span id="Substring">Substring</span>
+<p>根据指定的位置和长度截取子字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func Substring(s string, offset int, length uint) string
+```
+<b>例子:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+	result1 := strutil.Substring("abcde", 1, 3)
+	fmt.Println(result1) //bcd
+
+	result2 := strutil.Substring("abcde", 1, 5)
+	fmt.Println(result2) //bcde
+
+	result3 := strutil.Substring("abcde", -1, 3)
+	fmt.Println(result3) //e
+
+	result4 := strutil.Substring("abcde", -2, 2)
+	fmt.Println(result4) //de
+
+	result5 := strutil.Substring("abcde", -2, 3)
+	fmt.Println(result5) //de
+
+	result6 := strutil.Substring("你好，欢迎你", 0, 2)
+	fmt.Println(result6) //你好
+}
+```
 
 
 ### <span id="Wrap">Wrap</span>

docs/system.md

@@ -102,7 +102,7 @@ import (
 )
 
 func main() {
-	isOsMac := system.IsMac
+	isOsMac := system.IsMac()
 	fmt.Println(isOsMac)
 }
 ```
@@ -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")
+	// linux or mac
-	fmt.Println(out)
+	stdout, stderr, err := system.ExecCommand("ls")
-	fmt.Println(errout)
+	fmt.Println("std out: ", stdout)
-	fmt.Println(err)
+	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

@@ -26,7 +26,6 @@ import (
 - [GetOsEnv](#GetOsEnv)
 - [SetOsEnv](#SetOsEnv)
 - [RemoveOsEnv](#RemoveOsEnv)
-
 - [CompareOsEnv](#CompareOsEnv)
 - [ExecCommand](#ExecCommand)
 - [GetOsBits](#GetOsBits)
@@ -103,7 +102,7 @@ import (
 )
 
 func main() {
-	isOsMac := system.IsMac
+	isOsMac := system.IsMac()
 	fmt.Println(isOsMac)
 }
 ```
@@ -212,7 +211,7 @@ 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 +227,24 @@ import (
 )
 
 func main() {
-	out, errout, err := system.ExecCommand("ls")
+	// linux or mac
-	fmt.Println(out)
+	stdout, stderr, err := system.ExecCommand("ls")
-	fmt.Println(errout)
+	fmt.Println("std out: ", stdout)
-	fmt.Println(err)
+	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

@@ -34,7 +34,6 @@ import (
 - [IsCreditCard](#IsCreditCard)
 - [IsDns](#IsDns)
 - [IsEmail](#IsEmail)
-  
 - [IsEmptyString](#IsEmptyString)
 - [IsFloatStr](#IsFloatStr)
 - [IsNumberStr](#IsNumberStr)
@@ -48,6 +47,7 @@ import (
 - [IsUrl](#IsUrl)
 - [IsWeakPassword](#IsWeakPassword)
 - [IsZeroValue](#IsZeroValue)
+- [IsGBK](#IsGBK)
   
 
 <div STYLE="page-break-after: always;"></div>
@@ -822,7 +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

@@ -34,7 +34,6 @@ import (
 - [IsCreditCard](#IsCreditCard)
 - [IsDns](#IsDns)
 - [IsEmail](#IsEmail)
-  
 - [IsEmptyString](#IsEmptyString)
 - [IsFloatStr](#IsFloatStr)
 - [IsNumberStr](#IsNumberStr)
@@ -48,6 +47,7 @@ import (
 - [IsUrl](#IsUrl)
 - [IsWeakPassword](#IsWeakPassword)
 - [IsZeroValue](#IsZeroValue)
+- [IsGBK](#IsGBK)
   
 
 <div STYLE="page-break-after: always;"></div>
@@ -459,8 +459,6 @@ func main() {
 
 
 
-
-
 ### <span id="IsEmptyString">IsEmptyString</span>
 <p>验证字符串是否是空字符串</p>
 
@@ -488,7 +486,6 @@ func main() {
 
 
 
-
 ### <span id="IsFloatStr">IsFloatStr</span>
 <p>验证字符串是否是可以转换为浮点数</p>
 
@@ -574,8 +571,6 @@ func main() {
 ```
 
 
-
-
 ### <span id="IsRegexMatch">IsRegexMatch</span>
 <p>验证字符串是否可以匹配正则表达式</p>
 
@@ -601,7 +596,6 @@ func main() {
 
 
 
-
 ### <span id="IsIntStr">IsIntStr</span>
 <p>验证字符串是否是可以转换为整数</p>
 
@@ -821,3 +815,31 @@ 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

@@ -8,9 +8,9 @@ import (
 	"archive/zip"
 	"bufio"
 	"errors"
+	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"net/http"
 	"os"
 	"path"
@@ -18,7 +18,8 @@ import (
 	"strings"
 )
 
-// IsExist checks if a file or directory exists
+// IsExist checks if a file or directory exists.
+// Play: https://go.dev/play/p/nKKXt8ZQbmh
 func IsExist(path string) bool {
 	_, err := os.Stat(path)
 	if err == nil {
@@ -30,7 +31,8 @@ func IsExist(path string) bool {
 	return false
 }
 
-// CreateFile create a file in path
+// CreateFile create a file in path.
+// Play: https://go.dev/play/p/lDt8PEsTNKI
 func CreateFile(path string) bool {
 	file, err := os.Create(path)
 	if err != nil {
@@ -41,12 +43,14 @@ func CreateFile(path string) bool {
 	return true
 }
 
-// CreateDir create directory in absolute path. param `absPath` like /a/, /a/b/
+// CreateDir create directory in absolute path. param `absPath` like /a/, /a/b/.
+// Play: https://go.dev/play/p/qUuCe1OGQnM
 func CreateDir(absPath string) error {
 	return os.MkdirAll(path.Dir(absPath), os.ModePerm)
 }
 
-// IsDir checks if the path is directory or not
+// IsDir checks if the path is directory or not.
+// Play: https://go.dev/play/p/WkVwEKqtOWk
 func IsDir(path string) bool {
 	file, err := os.Stat(path)
 	if err != nil {
@@ -55,12 +59,14 @@ func IsDir(path string) bool {
 	return file.IsDir()
 }
 
-// RemoveFile remove the path file
+// RemoveFile remove the path file.
+// Play: https://go.dev/play/p/P2y0XW8a1SH
 func RemoveFile(path string) error {
 	return os.Remove(path)
 }
 
-// CopyFile copy src file to dest file
+// CopyFile copy src file to dest file.
+// Play: https://go.dev/play/p/Jg9AMJMLrJi
 func CopyFile(srcFilePath string, dstFilePath string) error {
 	srcFile, err := os.Open(srcFilePath)
 	if err != nil {
@@ -77,17 +83,21 @@ 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
+		}
 	}
 }
 
-//ClearFile write empty string to path file
+// ClearFile write empty string to path file.
+// Play: https://go.dev/play/p/NRZ0ZT-G94H
 func ClearFile(path string) error {
 	f, err := os.OpenFile(path, os.O_WRONLY|os.O_TRUNC, 0777)
 	if err != nil {
@@ -99,16 +109,18 @@ func ClearFile(path string) error {
 	return err
 }
 
-//ReadFileToString return string of file content
+// ReadFileToString return string of file content.
+// Play: https://go.dev/play/p/cmfwp_5SQTp
 func ReadFileToString(path string) (string, error) {
-	bytes, err := ioutil.ReadFile(path)
+	bytes, err := os.ReadFile(path)
 	if err != nil {
 		return "", err
 	}
 	return string(bytes), nil
 }
 
-// ReadFileByLine read file line by line
+// ReadFileByLine read file line by line.
+// Play: https://go.dev/play/p/svJP_7ZrBrD
 func ReadFileByLine(path string) ([]string, error) {
 	f, err := os.Open(path)
 	if err != nil {
@@ -134,13 +146,14 @@ func ReadFileByLine(path string) ([]string, error) {
 	return result, nil
 }
 
-// ListFileNames return all file names in the path
+// ListFileNames return all file names in the path.
+// Play: https://go.dev/play/p/Tjd7Y07rejl
 func ListFileNames(path string) ([]string, error) {
 	if !IsExist(path) {
 		return []string{}, nil
 	}
 
-	fs, err := ioutil.ReadDir(path)
+	fs, err := os.ReadDir(path)
 	if err != nil {
 		return []string{}, err
 	}
@@ -160,7 +173,8 @@ func ListFileNames(path string) ([]string, error) {
 	return result, nil
 }
 
-// Zip create zip file, fpath could be a single file or a directory
+// Zip create zip file, fpath could be a single file or a directory.
+// Play: https://go.dev/play/p/j-3sWBp8ik_P
 func Zip(fpath string, destPath string) error {
 	zipFile, err := os.Create(destPath)
 	if err != nil {
@@ -171,7 +185,7 @@ 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
 		}
@@ -208,11 +222,17 @@ func Zip(fpath string, destPath string) error {
 		return nil
 	})
 
+	if err != nil {
+		return err
+	}
+
 	return nil
 }
 
-// UnZip unzip the file and save it to destPath
+// UnZip unzip the file and save it to destPath.
+// Play: https://go.dev/play/p/g0w34kS7B8m
 func UnZip(zipFile string, destPath string) error {
+
 	zipReader, err := zip.OpenReader(zipFile)
 	if err != nil {
 		return err
@@ -220,11 +240,20 @@ func UnZip(zipFile string, destPath string) error {
 	defer zipReader.Close()
 
 	for _, f := range zipReader.File {
-		path := filepath.Join(destPath, f.Name)
+		//issue#62: fix ZipSlip bug
+		path, err := safeFilepathJoin(destPath, f.Name)
+		if err != nil {
+			return err
+		}
+
 		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
 			}
 
@@ -249,7 +278,19 @@ func UnZip(zipFile string, destPath string) error {
 	return nil
 }
 
-// IsLink checks if a file is symbol link or not
+func safeFilepathJoin(path1, path2 string) (string, error) {
+	relPath, err := filepath.Rel(".", path2)
+	if err != nil || strings.HasPrefix(relPath, "..") {
+		return "", fmt.Errorf("(zipslip) filepath is unsafe %q: %v", path2, err)
+	}
+	if path1 == "" {
+		path1 = "."
+	}
+	return filepath.Join(path1, filepath.Join("/", relPath)), nil
+}
+
+// IsLink checks if a file is symbol link or not.
+// Play: https://go.dev/play/p/TL-b-Kzvf44
 func IsLink(path string) bool {
 	fi, err := os.Lstat(path)
 	if err != nil {
@@ -258,7 +299,8 @@ func IsLink(path string) bool {
 	return fi.Mode()&os.ModeSymlink != 0
 }
 
-// FileMode return file's mode and permission
+// FileMode return file's mode and permission.
+// Play: https://go.dev/play/p/2l2hI42fA3p
 func FileMode(path string) (fs.FileMode, error) {
 	fi, err := os.Lstat(path)
 	if err != nil {
@@ -268,7 +310,8 @@ func FileMode(path string) (fs.FileMode, error) {
 }
 
 // MiMeType return file mime type
-// param `file` should be string(file path) or *os.File
+// param `file` should be string(file path) or *os.File.
+// Play: https://go.dev/play/p/bd5sevSUZNu
 func MiMeType(file any) string {
 	var mediatype string
 

fileutil/file_example_test.go

@@ -0,0 +1,225 @@
+package fileutil
+
+import (
+	"fmt"
+	"os"
+)
+
+func ExampleIsExist() {
+
+	result1 := IsExist("./")
+	result2 := IsExist("./xxx.go")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleCreateFile() {
+	fname := "./test.txt"
+
+	result1 := IsExist(fname)
+
+	CreateFile(fname)
+
+	result2 := IsExist(fname)
+
+	os.Remove(fname)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// false
+	// true
+}
+
+func ExampleCreateDir() {
+	pwd, _ := os.Getwd()
+	dirPath := pwd + "/test_xxx/"
+
+	result1 := IsExist(dirPath)
+
+	err := CreateDir(dirPath)
+	if err != nil {
+		return
+	}
+
+	result2 := IsExist(dirPath)
+
+	os.Remove(dirPath)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// false
+	// true
+}
+
+func ExampleIsDir() {
+
+	result1 := IsDir("./")
+	result2 := IsDir("./xxx.go")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleRemoveFile() {
+	srcFile := "./text.txt"
+	CreateFile(srcFile)
+
+	copyFile := "./text_copy.txt"
+	err := CopyFile(srcFile, copyFile)
+	if err != nil {
+		return
+	}
+	file, err := os.Open(copyFile)
+	if err != nil {
+		return
+	}
+	result1 := IsExist(copyFile)
+	result2 := file.Name()
+
+	os.Remove(srcFile)
+	os.Remove(copyFile)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// ./text_copy.txt
+}
+
+func ExampleReadFileToString() {
+	fname := "./test.txt"
+	CreateFile(fname)
+
+	f, _ := os.OpenFile(fname, os.O_WRONLY|os.O_TRUNC, 0777)
+	defer f.Close()
+
+	_, err := f.WriteString("hello world")
+	if err != nil {
+		return
+	}
+
+	content, _ := ReadFileToString(fname)
+
+	os.Remove(fname)
+
+	fmt.Println(content)
+
+	// Output:
+	// hello world
+}
+
+func ExampleClearFile() {
+	fname := "./test.txt"
+	CreateFile(fname)
+
+	f, _ := os.OpenFile(fname, os.O_WRONLY|os.O_TRUNC, 0777)
+	defer f.Close()
+
+	_, err := f.WriteString("hello world")
+	if err != nil {
+		return
+	}
+
+	content1, _ := ReadFileToString(fname)
+
+	err = ClearFile(fname)
+	if err != nil {
+		return
+	}
+	content2, _ := ReadFileToString(fname)
+
+	os.Remove(fname)
+
+	fmt.Println(content1)
+	fmt.Println(content2)
+
+	// Output:
+	// hello world
+	//
+}
+
+func ExampleReadFileByLine() {
+	fname := "./test.txt"
+	CreateFile(fname)
+
+	f, _ := os.OpenFile(fname, os.O_WRONLY|os.O_TRUNC, 0777)
+	defer f.Close()
+
+	_, err := f.WriteString("hello\nworld")
+	if err != nil {
+		return
+	}
+
+	content, _ := ReadFileByLine(fname)
+
+	os.Remove(fname)
+
+	fmt.Println(content)
+
+	// Output:
+	// [hello world]
+}
+
+func ExampleListFileNames() {
+	fileList, _ := ListFileNames("./")
+	fmt.Println(fileList)
+
+	// Output:
+	// [file.go file_example_test.go file_test.go]
+}
+
+func ExampleZip() {
+	srcFile := "./test.txt"
+	CreateFile(srcFile)
+
+	zipFile := "./test.zip"
+	err := Zip(srcFile, zipFile)
+	if err != nil {
+		return
+	}
+
+	result := IsExist(zipFile)
+
+	os.Remove(srcFile)
+	os.Remove(zipFile)
+
+	fmt.Println(result)
+
+	// Output:
+	// true
+}
+
+func ExampleUnZip() {
+	fname := "./test.txt"
+	file, _ := os.Create(fname)
+
+	_, err := file.WriteString("hello\nworld")
+	if err != nil {
+		return
+	}
+
+	f, _ := os.Open(fname)
+	defer f.Close()
+
+	mimeType := MiMeType(f)
+	fmt.Println(mimeType)
+
+	os.Remove(fname)
+
+	// Output:
+	// application/octet-stream
+}

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 +4,68 @@
 // Package formatter implements some functions to format string, struct.
 package formatter
 
-import "strings"
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+	"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"
+// Play: https://go.dev/play/p/eRD5k2vzUVX
+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)
 }
+
+func commaString(s string) string {
+	if len(s) <= 3 {
+		return s
+	}
+	return commaString(s[:len(s)-3]) + "," + commaString(s[len(s)-3:])
+}
+
+func numberToString(value any) (string, error) {
+	switch reflect.TypeOf(value).Kind() {
+	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 "", err
+				}
+				return sv, nil
+			} else {
+				_, err := strconv.ParseInt(sv, 10, 64)
+				if err != nil {
+					return "", nil
+				}
+				return sv, nil
+			}
+		}
+	default:
+		return "", nil
+	}
+}

formatter/formatter_example_test.go

@@ -0,0 +1,18 @@
+package formatter
+
+import "fmt"
+
+func ExampleComma() {
+	result1 := Comma("123", "")
+	result2 := Comma("12345", "$")
+	result3 := Comma(1234567, "￥")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// 123
+	// $12,345
+	// ￥1,234,567
+}

formatter/formatter_internal.go

@@ -1,40 +0,0 @@
-package formatter
-
-import (
-	"fmt"
-	"reflect"
-	"strconv"
-	"strings"
-)
-
-func commaString(s string) string {
-	if len(s) <= 3 {
-		return s
-	}
-	return commaString(s[:len(s)-3]) + "," + commaString(s[len(s)-3:])
-}
-
-func numString(value any) string {
-	switch reflect.TypeOf(value).Kind() {
-	case reflect.Int, reflect.Int64, reflect.Float32, reflect.Float64:
-		return fmt.Sprintf("%v", value)
-	case reflect.String:
-		{
-			sv := fmt.Sprintf("%v", value)
-			if strings.Contains(sv, ".") {
-				_, err := strconv.ParseFloat(sv, 64)
-				if err == nil {
-					return sv
-				}
-			} else {
-				_, err := strconv.ParseInt(sv, 10, 64)
-				if err == nil {
-					return sv
-				}
-			}
-		}
-	default:
-		return ""
-	}
-	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

@@ -5,11 +5,13 @@
 package function
 
 import (
+	"fmt"
 	"reflect"
 	"time"
 )
 
-// After creates a function that invokes func once it's called n or more times
+// After creates a function that invokes func once it's called n or more times.
+// Play: https://go.dev/play/p/8mQhkFmsgqs
 func After(n int, fn any) func(args ...any) []reflect.Value {
 	// Catch programming error while constructing the closure
 	mustBeFunction(fn)
@@ -23,7 +25,8 @@ func After(n int, fn any) func(args ...any) []reflect.Value {
 	}
 }
 
-// Before creates a function that invokes func once it's called less than n times
+// Before creates a function that invokes func once it's called less than n times.
+// Play: https://go.dev/play/p/0HqUDIFZ3IL
 func Before(n int, fn any) func(args ...any) []reflect.Value {
 	// Catch programming error while constructing the closure
 	mustBeFunction(fn)
@@ -40,41 +43,48 @@ func Before(n int, fn any) func(args ...any) []reflect.Value {
 	}
 }
 
-// Fn is for curry function which is func(...any) any
+// CurryFn is for make curry function
-type Fn func(...any) any
+type CurryFn[T any] func(...T) T
 
-// Curry make a curry function
+// New make a curry function for specific value.
-func (f Fn) Curry(i any) func(...any) any {
+// Play: Todo
-	return func(values ...any) any {
+func (cf CurryFn[T]) New(val T) func(...T) T {
-		v := append([]any{i}, values...)
+	return func(vals ...T) T {
-		return f(v...)
+		args := append([]T{val}, vals...)
+		return cf(args...)
 	}
 }
 
-// Compose compose the functions from right to left
+// Compose compose the functions from right to left.
-func Compose(fnList ...func(...any) any) func(...any) any {
+// Play: Todo
-	return func(s ...any) any {
+func Compose[T any](fnList ...func(...T) T) func(...T) T {
-		f := fnList[0]
+	return func(args ...T) T {
-		restFn := fnList[1:]
+		firstFn := fnList[0]
+		restFns := fnList[1:]
 
 		if len(fnList) == 1 {
-			return f(s...)
+			return firstFn(args...)
 		}
 
-		return f(Compose(restFn...)(s...))
+		fn := Compose(restFns...)
+		arg := fn(args...)
+
+		return firstFn(arg)
 	}
 }
 
-// Delay make the function execution after delayed time
+// Delay make the function execution after delayed time.
+// Play: https://go.dev/play/p/Ivtc2ZE-Tye
 func Delay(delay time.Duration, fn any, args ...any) {
 	// Catch programming error while constructing the closure
 	mustBeFunction(fn)
 
 	time.Sleep(delay)
-	invokeFunc(fn, args...)
+	unsafeInvokeFunc(fn, args...)
 }
 
 // Debounced creates a debounced function that delays invoking fn until after wait duration have elapsed since the last time the debounced function was invoked.
+// Play: https://go.dev/play/p/absuEGB_GN7
 func Debounced(fn func(), duration time.Duration) func() {
 	// Catch programming error while constructing the closure
 	mustBeFunction(fn)
@@ -84,17 +94,16 @@ func Debounced(fn func(), duration time.Duration) func() {
 
 	go func() {
 		for {
-			select {
+			<-timer.C
-			case <-timer.C:
+			go fn()
-				go fn()
-			}
 		}
 	}()
 
 	return func() { timer.Reset(duration) }
 }
 
-// Schedule invoke function every duration time, util close the returned bool chan
+// Schedule invoke function every duration time, util close the returned bool channel.
+// Play: https://go.dev/play/p/hbON-Xeyn5N
 func Schedule(d time.Duration, fn any, args ...any) chan bool {
 	// Catch programming error while constructing the closure
 	mustBeFunction(fn)
@@ -113,3 +122,40 @@ 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.
+// Play: https://go.dev/play/p/mPdUVvj6HD6
+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
+	}
+}
+
+func unsafeInvokeFunc(fn any, args ...any) []reflect.Value {
+	fv := reflect.ValueOf(fn)
+	params := make([]reflect.Value, len(args))
+	for i, item := range args {
+		params[i] = reflect.ValueOf(item)
+	}
+	return fv.Call(params)
+}
+
+func functionValue(function any) reflect.Value {
+	v := reflect.ValueOf(function)
+	if v.Kind() != reflect.Func {
+		panic(fmt.Sprintf("Invalid function type, value of type %T", function))
+	}
+	return v
+}
+
+func mustBeFunction(function any) {
+	v := reflect.ValueOf(function)
+	if v.Kind() != reflect.Func {
+		panic(fmt.Sprintf("Invalid function type, value of type %T", function))
+	}
+}

function/function_example_test.go

@@ -0,0 +1,147 @@
+package function
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+func ExampleAfter() {
+	fn := After(2, func() {
+		fmt.Println("test")
+	})
+
+	fn()
+	fn()
+
+	// Output:
+	// test
+}
+
+func ExampleBefore() {
+	fn := Before(2, func() {
+		fmt.Println("test")
+	})
+
+	fn()
+	fn()
+	fn()
+	fn()
+
+	// Output:
+	// test
+	// test
+}
+
+func ExampleCurryFn_New() {
+	add := func(a, b int) int {
+		return a + b
+	}
+
+	var addCurry CurryFn[int] = func(values ...int) int {
+		return add(values[0], values[1])
+	}
+	add1 := addCurry.New(1)
+
+	result := add1(2)
+
+	fmt.Println(result)
+
+	// Output:
+	// 3
+}
+
+func ExampleCompose() {
+	toUpper := func(strs ...string) string {
+		return strings.ToUpper(strs[0])
+	}
+	toLower := func(strs ...string) string {
+		return strings.ToLower(strs[0])
+	}
+	transform := Compose(toUpper, toLower)
+
+	result := transform("aBCde")
+
+	fmt.Println(result)
+
+	// Output:
+	// ABCDE
+}
+
+func ExampleDelay() {
+	var print = func(s string) {
+		fmt.Println(s)
+	}
+
+	Delay(2*time.Second, print, "hello")
+
+	// Output:
+	// hello
+}
+
+func ExampleDebounced() {
+	count := 0
+	add := func() {
+		count++
+	}
+
+	debouncedAdd := Debounced(add, 50*time.Microsecond)
+
+	debouncedAdd()
+	debouncedAdd()
+	debouncedAdd()
+	debouncedAdd()
+
+	time.Sleep(100 * time.Millisecond)
+
+	fmt.Println(count)
+
+	debouncedAdd()
+
+	time.Sleep(100 * time.Millisecond)
+
+	fmt.Println(count)
+
+	// Output:
+	// 1
+	// 2
+}
+
+func ExampleSchedule() {
+	var result []string
+
+	appendFn := func(s string) {
+		result = append(result, s)
+	}
+
+	stop := Schedule(1*time.Second, appendFn, "*")
+
+	time.Sleep(3 * time.Second)
+	close(stop)
+
+	fmt.Println(result)
+
+	// Output:
+	// [* * *]
+}
+
+func ExamplePipeline() {
+	addOne := func(x int) int {
+		return x + 1
+	}
+	double := func(x int) int {
+		return 2 * x
+	}
+	square := func(x int) int {
+		return x * x
+	}
+
+	fn := Pipeline(addOne, double, square)
+
+	result := fn(2)
+
+	fmt.Println(result)
+
+	// Output:
+	// 36
+}

function/function_internal.go

@@ -1,39 +0,0 @@
-package function
-
-import (
-	"fmt"
-	"reflect"
-)
-
-func invokeFunc(fn any, args ...any) []reflect.Value {
-	fv := functionValue(fn)
-	params := make([]reflect.Value, len(args))
-	for i, item := range args {
-		params[i] = reflect.ValueOf(item)
-	}
-	return fv.Call(params)
-}
-
-func unsafeInvokeFunc(fn any, args ...any) []reflect.Value {
-	fv := reflect.ValueOf(fn)
-	params := make([]reflect.Value, len(args))
-	for i, item := range args {
-		params[i] = reflect.ValueOf(item)
-	}
-	return fv.Call(params)
-}
-
-func functionValue(function any) reflect.Value {
-	v := reflect.ValueOf(function)
-	if v.Kind() != reflect.Func {
-		panic(fmt.Sprintf("Invalid function type, value of type %T", function))
-	}
-	return v
-}
-
-func mustBeFunction(function any) {
-	v := reflect.ValueOf(function)
-	if v.Kind() != reflect.Func {
-		panic(fmt.Sprintf("Invalid function type, value of type %T", function))
-	}
-}

function/function_test.go

@@ -62,24 +62,26 @@ func TestCurry(t *testing.T) {
 	add := func(a, b int) int {
 		return a + b
 	}
-	var addCurry Fn = func(values ...any) any {
+	var addCurry CurryFn[int] = func(values ...int) int {
-		return add(values[0].(int), values[1].(int))
+		return add(values[0], values[1])
 	}
-	add1 := addCurry.Curry(1)
+	add1 := addCurry.New(1)
+
 	assert.Equal(3, add1(2))
 }
 
 func TestCompose(t *testing.T) {
 	assert := internal.NewAssert(t, "TestCompose")
 
-	toUpper := func(a ...any) any {
+	toUpper := func(strs ...string) string {
-		return strings.ToUpper(a[0].(string))
+		return strings.ToUpper(strs[0])
 	}
-	toLower := func(a ...any) any {
+	toLower := func(strs ...string) string {
-		return strings.ToLower(a[0].(string))
+		return strings.ToLower(strs[0])
 	}
 
 	expected := toUpper(toLower("aBCde"))
+
 	cf := Compose(toUpper, toLower)
 	res := cf("aBCde")
 
@@ -134,3 +136,21 @@ 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.go

@@ -3,12 +3,18 @@ package function
 import "time"
 
 // Watcher is used for record code excution time
+// Play: Todo
 type Watcher struct {
 	startTime int64
 	stopTime  int64
 	excuting  bool
 }
 
+// Start the watch timer.
+func NewWatcher() *Watcher {
+	return &Watcher{}
+}
+
 // Start the watch timer.
 func (w *Watcher) Start() {
 	w.startTime = time.Now().UnixNano()

function/watcher_example_test.go

@@ -0,0 +1,22 @@
+package function
+
+import "fmt"
+
+func ExampleWatcher() {
+	w := NewWatcher()
+
+	w.Start()
+
+	longRunningTask()
+
+	w.Stop()
+
+	// eapsedTime := w.GetElapsedTime().Milliseconds()
+
+	fmt.Println("foo")
+
+	w.Reset()
+
+	// Output:
+	// foo
+}

function/watcher_test.go

@@ -9,7 +9,7 @@ import (
 func TestWatcher(t *testing.T) {
 	assert := internal.NewAssert(t, "TestWatcher")
 
-	w := &Watcher{}
+	w := NewWatcher()
 	w.Start()
 
 	longRunningTask()
@@ -29,9 +29,10 @@ func TestWatcher(t *testing.T) {
 	assert.Equal(int64(0), w.stopTime)
 }
 
-func longRunningTask() {
+func longRunningTask() []int64 {
-	var slice []int64
+	var data []int64
 	for i := 0; i < 10000000; i++ {
-		slice = append(slice, int64(i))
+		data = append(data, int64(i))
 	}
+	return data
 }

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

@@ -0,0 +1,207 @@
+// Copyright 2022 dudaodong@gmail.com. All rights resulterved.
+// Use of this source code is governed by MIT license
+
+// Package iterator provides a way to iterate over values stored in containers.
+// note:
+// 1. Full feature iterator is complicated, this package is just a experiment to explore how iterators could work in Go.
+// 2. The functionality of this package is very simple and limited, may not meet the actual dev needs.
+// 3. It is currently under development, unstable, and will not be completed for some time in the future.
+// So, based on above factors, you may not use it in production. but, anyone is welcome to improve it.
+// 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 (
+	"context"
+
+	"golang.org/x/exp/constraints"
+)
+
+// Iterator supports iterating over a sequence of values of type `E`.
+type Iterator[T any] interface {
+	// Next checks if there is a next value in the iteration or not
+	HasNext() bool
+	// Next returns the next value in the iteration if there is one,
+	// and reports whether the returned value is valid.
+	// Once Next returns ok==false, the iteration is over,
+	// and all subsequent calls will return ok==false.
+	Next() (item T, ok bool)
+}
+
+// StopIterator is an  interface for stopping Iterator.
+type StopIterator[T any] interface {
+	Iterator[T]
+
+	// Stop indicates that the iterator will no longer be used.
+	// After a call to Stop, future calls to Next may panic.
+	// Stop may be called multiple times;
+	// all calls after the first will have no effect.
+	Stop()
+}
+
+// DeleteIter is an Iter that implements a Delete method.
+type DeleteIterator[T any] interface {
+	Iterator[T]
+
+	// Delete deletes the current iterator element;
+	// that is, the one returned by the last call to Next.
+	// Delete should panic if called before Next or after
+	// Next returns false.
+	Delete()
+}
+
+// SetIterator is an Iter that implements a Set method.
+type SetIterator[T any] interface {
+	Iterator[T]
+
+	// Set replaces the current iterator element with v.
+	// Set should panic if called before Next or after
+	// Next returns false.
+	Set(v T)
+}
+
+// PrevIterator is an iterator with a Prev method.
+type PrevIterator[T any] interface {
+	Iterator[T]
+
+	// Prev moves the iterator to the previous position.
+	// After calling Prev, Next will return the value at
+	// that position in the container. For example, after
+	//   it.Next() returning (v, true)
+	//   it.Prev()
+	// another call to it.Next will again return (v, true).
+	// Calling Prev before calling Next may panic.
+	// Calling Prev after Next returns false will move
+	// to the last element, or, if there are no elements,
+	// to the iterator's initial state.
+	Prev()
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Functions that create an Iterator from some other type.                                       //
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+// FromSlice returns an iterator over a slice of data.
+func FromSlice[T any](slice []T) Iterator[T] {
+	return &sliceIterator[T]{slice: slice, index: -1}
+}
+
+func ToSlice[T any](iter Iterator[T]) []T {
+	result := []T{}
+	for item, ok := iter.Next(); ok; item, ok = iter.Next() {
+		result = append(result, item)
+	}
+	return result
+}
+
+type sliceIterator[T any] struct {
+	slice []T
+	index int
+}
+
+func (iter *sliceIterator[T]) HasNext() bool {
+	return iter.index < len(iter.slice)-1
+}
+
+func (iter *sliceIterator[T]) Next() (T, bool) {
+	iter.index++
+
+	ok := iter.index >= 0 && iter.index < len(iter.slice)
+
+	var item T
+	if ok {
+		item = iter.slice[iter.index]
+	}
+
+	return item, ok
+}
+
+// Prev implements PrevIterator.
+func (iter *sliceIterator[T]) Prev() {
+	if iter.index == -1 {
+		panic("Next function should be called Prev")
+	}
+	if iter.HasNext() {
+		iter.index--
+	} else {
+		iter.index = len(iter.slice) - 1
+	}
+}
+
+// Set implements SetIterator.
+func (iter *sliceIterator[T]) Set(value T) {
+	if iter.index == -1 {
+		panic("Next function should be called Set")
+	}
+	if iter.index >= len(iter.slice) || len(iter.slice) == 0 {
+		panic("No element in current iterator")
+	}
+	iter.slice[iter.index] = value
+}
+
+// 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 constraints.Integer | constraints.Float](start, end, step T) Iterator[T] {
+	if end < start {
+		panic("RangeIterator: start should be before end")
+	} else if step <= 0 {
+		panic("RangeIterator: step should be positive")
+	}
+
+	return &rangeIterator[T]{start: start, end: end, step: step}
+}
+
+type rangeIterator[T constraints.Integer | constraints.Float] struct {
+	start, end, step T
+}
+
+func (iter *rangeIterator[T]) HasNext() bool {
+	return iter.start < iter.end
+}
+
+func (iter *rangeIterator[T]) Next() (T, bool) {
+	if iter.start >= iter.end {
+		var zero T
+		return zero, false
+	}
+	num := iter.start
+	iter.start += iter.step
+	return num, true
+}
+
+// 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 FromChannel[T any](channel <-chan T) Iterator[T] {
+	return &channelIterator[T]{channel: channel}
+}
+
+type channelIterator[T any] struct {
+	channel <-chan T
+}
+
+func (iter *channelIterator[T]) Next() (T, bool) {
+	item, ok := <-iter.channel
+	return item, ok
+}
+
+func (iter *channelIterator[T]) HasNext() bool {
+	return len(iter.channel) == 0
+}
+
+// ToChannel create a new goroutine to pull items from the channel iterator to the returned channel.
+func ToChannel[T any](ctx context.Context, iter Iterator[T], buffer int) <-chan T {
+	result := make(chan T, buffer)
+
+	go func() {
+		defer close(result)
+
+		for item, ok := iter.Next(); ok; item, ok = iter.Next() {
+			select {
+			case result <- item:
+			case <-ctx.Done():
+				return
+			}
+		}
+	}()
+
+	return result
+}

iterator/iterator_test.go

@@ -0,0 +1,103 @@
+// Copyright 2022 dudaodong@gmail.com. All rights resulterved.
+// Use of this source code is governed by MIT license
+
+// Package iterator implements some feature of C++ STL iterators
+package iterator
+
+import (
+	"context"
+	"testing"
+
+	"github.com/duke-git/lancet/v2/internal"
+)
+
+func TestSliceIterator(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSliceIterator")
+
+	// HashNext
+	t.Run("slice iterator HasNext: ", func(t *testing.T) {
+		iter1 := FromSlice([]int{1, 2, 3, 4})
+		for {
+			item, _ := iter1.Next()
+
+			if item == 4 {
+				assert.Equal(false, iter1.HasNext())
+				break
+			} else {
+				assert.Equal(true, iter1.HasNext())
+			}
+		}
+
+		iter2 := FromSlice([]int{})
+		assert.Equal(false, iter2.HasNext())
+	})
+
+	//Next
+	t.Run("slice iterator Next: ", func(t *testing.T) {
+		iter1 := FromSlice([]int{1, 2, 3, 4})
+		for i := 0; i < 4; i++ {
+			item, ok := iter1.Next()
+			if !ok {
+				break
+			}
+			assert.Equal(i+1, item)
+		}
+
+		iter2 := FromSlice([]int{})
+		_, ok := iter2.Next()
+		assert.Equal(false, ok)
+	})
+
+	t.Run("slice iterator ToSlice: ", func(t *testing.T) {
+		iter := FromSlice([]int{1, 2, 3, 4})
+		item, _ := iter.Next()
+		assert.Equal(1, item)
+
+		data := ToSlice(iter)
+		assert.Equal([]int{2, 3, 4}, data)
+	})
+
+}
+
+func TestRangeIterator(t *testing.T) {
+	assert := internal.NewAssert(t, "TestRangeIterator")
+
+	t.Run("range iterator: ", func(t *testing.T) {
+		iter := FromRange(1, 4, 1)
+
+		item, ok := iter.Next()
+		assert.Equal(1, item)
+		assert.Equal(true, ok)
+
+		item, ok = iter.Next()
+		assert.Equal(2, item)
+		assert.Equal(true, ok)
+
+		item, ok = iter.Next()
+		assert.Equal(3, item)
+		assert.Equal(true, ok)
+
+		_, ok = iter.Next()
+		assert.Equal(false, ok)
+		assert.Equal(false, iter.HasNext())
+	})
+
+}
+
+func TestChannelIterator(t *testing.T) {
+	assert := internal.NewAssert(t, "TestRangeIterator")
+
+	iter := FromSlice([]int{1, 2, 3, 4})
+
+	ctx, cancel := context.WithCancel(context.Background())
+	iter = FromChannel(ToChannel(ctx, iter, 0))
+	item, ok := iter.Next()
+	assert.Equal(1, item)
+	assert.Equal(true, ok)
+	assert.Equal(true, iter.HasNext())
+
+	cancel()
+
+	_, ok = iter.Next()
+	assert.Equal(false, ok)
+}