doc: add document for stream package

README.md

@@ -711,12 +711,16 @@ import "github.com/duke-git/lancet/v2/mathutil"
     [[play](https://go.dev/play/p/akLWz0EqOSM)]
 -   **<big>AngleToRadian</big>** : converts angle value to radian value.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#AngleToRadian)]
+    [[play](https://go.dev/play/p/CIvlICqrHql)]
 -   **<big>RadianToAngle</big>** : converts radian value to angle value.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#RadianToAngle)]
+    [[play](https://go.dev/play/p/dQtmOTUOMgi)]
 -   **<big>PointDistance</big>** : get two points distance.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#PointDistance)]
+    [[play](https://go.dev/play/p/RrG4JIaziM8)]
 -   **<big>IsPrime</big>** : checks if number is prime number.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#IsPrime)]
+    [[play](https://go.dev/play/p/Rdd8UTHZJ7u)]
 
 ### 13. Netutil package contains functions to get net information and send http request.
 
@@ -1150,6 +1154,8 @@ import "github.com/duke-git/lancet/v2/strutil"
     [[play](https://go.dev/play/p/bj7_odx3vRf)]
 -   **<big>RemoveNonPrintable</big>** : remove non-printable characters from a string.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#RemoveNonPrintable)]
+    [[play](https://go.dev/play/p/og47F5x_jTZ)]
+
 
 ### 19. System package contain some functions about os, runtime, shell command.
 
@@ -1281,8 +1287,10 @@ import "github.com/duke-git/lancet/v2/validator"
     [[play](https://go.dev/play/p/E2nt3unlmzP)]
 -   **<big>IsASCII</big>** : checks if string is all ASCII char.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/validator.md#IsASCII)]
+    [[play](https://go.dev/play/p/hfQNPLX0jNa)]
 -   **<big>IsPrintable</big>** : checks if string is all printable chars.
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/validator.md#IsPrintable)]
+    [[play](https://go.dev/play/p/Pe1FE2gdtTP)]
 
 ### 21. xerror package implements helpers for errors.
 

README_zh-CN.md

@@ -710,12 +710,16 @@ import "github.com/duke-git/lancet/v2/mathutil"
     [[play](https://go.dev/play/p/akLWz0EqOSM)]
 -   **<big>AngleToRadian</big>** : 将角度值转为弧度值。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#AngleToRadian)]
+    [[play](https://go.dev/play/p/CIvlICqrHql)]
 -   **<big>RadianToAngle</big>** : 将弧度值转为角度值。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#RadianToAngle)]
+    [[play](https://go.dev/play/p/dQtmOTUOMgi)]
 -   **<big>PointDistance</big>** : 计算两个坐标点的距离。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#PointDistance)]
+    [[play](https://go.dev/play/p/RrG4JIaziM8)]
 -   **<big>IsPrime</big>** : 判断质数。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#IsPrime)]
+    [[play](https://go.dev/play/p/Rdd8UTHZJ7u)]
 
 ### 13. netutil 网络包支持获取 ip 地址，发送 http 请求。
 
@@ -1152,6 +1156,7 @@ import "github.com/duke-git/lancet/v2/strutil"
     [[play](https://go.dev/play/p/bj7_odx3vRf)]
 -   **<big>RemoveNonPrintable</big>** : 删除字符串中不可打印的字符。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#RemoveNonPrintable)]
+    [[play](https://go.dev/play/p/og47F5x_jTZ)]
 
 ### 19. system 包含 os, runtime, shell command 的相关函数。
 
@@ -1283,8 +1288,10 @@ import "github.com/duke-git/lancet/v2/validator"
     [[play](https://go.dev/play/p/E2nt3unlmzP)]
 -   **<big>IsASCII</big>** : 验证字符串全部为 ASCII 字符。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/validator_zh-CN.md#IsASCII)]
+    [[play](https://go.dev/play/p/hfQNPLX0jNa)]
 -   **<big>IsPrintable</big>** : 检查字符串是否全部为可打印字符。
     [[doc](https://github.com/duke-git/lancet/blob/main/docs/validator_zh-CN.md#IsPrintable)]
+    [[play](https://go.dev/play/p/Pe1FE2gdtTP)]
 
 ### 21. xerror 包实现一些错误处理函数
 

docs/fileutil.md

@@ -26,6 +26,7 @@ import (
 -   [CreateFile](#CreateFile)
 -   [CreateDir](#CreateDir)
 -   [CopyFile](#CopyFile)
+-   [CurrentPath](#CurrentPath)
 -   [FileMode](#FileMode)
 -   [MiMeType](#MiMeType)
 -   [IsExist](#IsExist)
@@ -151,6 +152,32 @@ func main() {
 }
 ```
 
+### <span id="CurrentPath">CurrentPath</span>
+
+<p>return current absolute path.</p>
+
+<b>Signature:</b>
+
+```go
+func CurrentPath() string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/fileutil"
+)
+
+func main() {
+    absPath := CurrentPath()
+    fmt.Println(absPath)
+}
+```
+
 ### <span id="FileMode">FileMode</span>
 
 <p>Return file mode infomation.</p>

docs/fileutil_zh-CN.md

@@ -26,6 +26,7 @@ import (
 -   [CreateFile](#CreateFile)
 -   [CreateDir](#CreateDir)
 -   [CopyFile](#CopyFile)
+-   [CurrentPath](#CurrentPath)
 -   [FileMode](#FileMode)
 -   [MiMeType](#MiMeType)
 -   [IsExist](#IsExist)
@@ -150,6 +151,32 @@ func main() {
 }
 ```
 
+### <span id="CurrentPath">CurrentPath</span>
+
+<p>返回当前位置的绝对路径。</p>
+
+<b>函数签名:</b>
+
+```go
+func CurrentPath() string
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/fileutil"
+)
+
+func main() {
+    absPath := CurrentPath()
+    fmt.Println(absPath)
+}
+```
+
 ### <span id="FileMode">FileMode</span>
 
 <p>获取文件mode信息</p>

docs/slice.md

@@ -63,6 +63,8 @@ import (
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce](#Reduce)
+-   [ReduceBy](#ReduceBy)
+-   [ReduceRight](#ReduceRight)
 -   [Replace](#Replace)
 -   [ReplaceAll](#ReplaceAll)
 -   [Repeat](#Repeat)
@@ -1504,6 +1506,72 @@ func main() {
 }
 ```
 
+### <span id="ReduceBy">ReduceBy</span>
+
+<p>Produces a value from slice by accumulating the result of each element as passed through the reducer function.</p>
+
+<b>Signature:</b>
+
+```go
+func ReduceBy[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.ReduceBy([]int{1, 2, 3, 4}, 0, func(_ int, item int, agg int) int {
+        return agg + item
+    })
+
+    result2 := slice.ReduceBy([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+        return agg + fmt.Sprintf("%v", item)
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // 10
+    // 1234
+}
+```
+
+### <span id="ReduceRight">ReduceRight</span>
+
+<p>ReduceRight is like ReduceBy, but it iterates over elements of slice from right to left.</p>
+
+<b>Signature:</b>
+
+```go
+func ReduceRight[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result := slice.ReduceRight([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+        return agg + fmt.Sprintf("%v", item)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 4321
+}
+```
+
 ### <span id="Replace">Replace</span>
 
 <p>Returns a copy of the slice with the first n non-overlapping instances of old replaced by new.</p>

docs/slice_zh-CN.md

@@ -63,6 +63,8 @@ import (
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce](#Reduce)
+-   [ReduceBy](#ReduceBy)
+-   [ReduceRight](#ReduceRight)
 -   [Replace](#Replace)
 -   [ReplaceAll](#ReplaceAll)
 -   [Repeat](#Repeat)
@@ -1505,6 +1507,72 @@ func main() {
 }
 ```
 
+### <span id="ReduceBy">ReduceBy</span>
+
+<p>对切片中执行reduce操作。</p>
+
+<b>函数签名:</b>
+
+```go
+func ReduceBy[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.ReduceBy([]int{1, 2, 3, 4}, 0, func(_ int, item int, agg int) int {
+        return agg + item
+    })
+
+    result2 := slice.ReduceBy([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+        return agg + fmt.Sprintf("%v", item)
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // 10
+    // 1234
+}
+```
+
+### <span id="ReduceRight">ReduceRight</span>
+
+<p>类似ReduceBy操作，迭代切片元素顺序从右至左。</p>
+
+<b>函数签名:</b>
+
+```go
+func ReduceRight[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result := slice.ReduceRight([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+        return agg + fmt.Sprintf("%v", item)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 4321
+}
+```
+
 ### <span id="Replace">Replace</span>
 
 <p>返回切片的副本，其中前n个不重叠的old替换为new</p>

docs/stream.md

@@ -0,0 +1,907 @@
+# Stream
+
+Package stream implements a sequence of elements supporting sequential and operations. This package is an experiment to explore if stream in go can work as the way java does. it's feature is very limited.
+
+<div STYLE="page-break-after: always;"></div>
+
+## Source:
+
+-   [https://github.com/duke-git/lancet/blob/main/stream/stream.go](https://github.com/duke-git/lancet/blob/main/stream/stream.go)
+
+<div STYLE="page-break-after: always;"></div>
+
+## Usage:
+
+```go
+import (
+    "github.com/duke-git/lancet/v2/stream"
+)
+```
+
+<div STYLE="page-break-after: always;"></div>
+
+## Index
+
+-   [Of](#Of)
+-   [FromSlice](#FromSlice)
+-   [FromChannel](#FromChannel)
+-   [FromRange](#FromRange)
+-   [Generate](#Generate)
+-   [Concat](#Concat)
+-   [Distinct](#Distinct)
+-   [Filter](#Filter)
+-   [Map](#Map)
+-   [Peek](#Peek)
+-   [Skip](#Skip)
+-   [Limit](#Limit)
+-   [Reverse](#Reverse)
+-   [Range](#Range)
+-   [Sorted](#Sorted)
+-   [ForEach](#ForEach)
+-   [Reduce](#Reduce)
+-   [FindFirst](#FindFirst)
+-   [Max](#Max)
+-   [Min](#Min)
+-   [AllMatch](#AllMatch)
+-   [AnyMatch](#AnyMatch)
+-   [NoneMatch](#NoneMatch)
+-   [Count](#Count)
+-   [ToSlice](#ToSlice)
+
+<div STYLE="page-break-after: always;"></div>
+
+## Documentation
+
+### <span id="Of">Of</span>
+
+<p>Creates a stream whose elements are the specified values.</p>
+
+<b>Signature:</b>
+
+```go
+func Of[T any](elems ...T) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.Of(1, 2, 3)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromSlice">FromSlice</span>
+
+<p>Creates a stream from slice.</p>
+
+<b>Signature:</b>
+
+```go
+func FromSlice[T any](source []T) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.FromSlice([]int{1, 2, 3})
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromChannel">FromChannel</span>
+
+<p>Creates a stream from channel.</p>
+
+<b>Signature:</b>
+
+```go
+func FromChannel[T any](source <-chan T) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    ch := make(chan int)
+    go func() {
+        for i := 1; i < 4; i++ {
+            ch <- i
+        }
+        close(ch)
+    }()
+
+    s := stream.FromChannel(ch)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromRange">FromRange</span>
+
+<p>Creates a number stream from start to end. both start and end are included. [start, end]</p>
+
+<b>Signature:</b>
+
+```go
+func FromRange[T constraints.Integer | constraints.Float](start, end, step T) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.FromRange(1, 5, 1)
+
+    data := s.ToSlice()
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3 4 5]
+}
+```
+
+### <span id="Generate">Generate</span>
+
+<p>Creates a stream where each element is generated by the provided generater function.</p>
+
+<b>Signature:</b>
+
+```go
+func Generate[T any](generator func() func() (item T, ok bool)) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    n := 0
+    max := 4
+
+    generator := func() func() (int, bool) {
+        return func() (int, bool) {
+            n++
+            return n, n < max
+        }
+    }
+
+    s := stream.Generate(generator)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="Concat">Concat</span>
+
+<p>Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream.</p>
+
+<b>Signature:</b>
+
+```go
+func Concat[T any](a, b stream[T]) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s1 := stream.FromSlice([]int{1, 2, 3})
+    s2 := stream.FromSlice([]int{4, 5, 6})
+
+    s := Concat(s1, s2)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3 4 5 6]
+}
+```
+
+### <span id="Distinct">Distinct</span>
+
+<p>Creates returns a stream that removes the duplicated items. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Distinct() stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 2, 3, 3, 3})
+    distinct := original.Distinct()
+
+    data1 := original.ToSlice()
+    data2 := distinct.ToSlice()
+
+    fmt.Println(data1)
+    fmt.Println(data2)
+
+    // Output:
+    // [1 2 2 3 3 3]
+    // [1 2 3]
+}
+```
+
+### <span id="Filter">Filter</span>
+
+<p>Returns a stream consisting of the elements of this stream that match the given predicate. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Filter(predicate func(item T) bool) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4, 5})
+
+    isEven := func(n int) bool {
+        return n%2 == 0
+    }
+
+    even := original.Filter(isEven)
+
+    fmt.Println(even.ToSlice())
+
+    // Output:
+    // [2 4]
+}
+```
+
+### <span id="Map">Map</span>
+
+<p>Returns a stream consisting of the elements of this stream that apply the given function to elements of stream. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Map(mapper func(item T) T) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    addOne := func(n int) int {
+        return n + 1
+    }
+
+    increament := original.Map(addOne)
+
+    fmt.Println(increament.ToSlice())
+
+    // Output:
+    // [2 3 4]
+}
+```
+
+### <span id="Peek">Peek</span>
+
+<p>Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Peek(consumer func(item T)) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    data := []string{}
+    peekStream := original.Peek(func(n int) {
+        data = append(data, fmt.Sprint("value", n))
+    })
+
+    fmt.Println(original.ToSlice())
+    fmt.Println(peekStream.ToSlice())
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+    // [1 2 3]
+    // [value1 value2 value3]
+}
+```
+
+### <span id="Skip">Skip</span>
+
+<p>Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Skip(n int) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4})
+
+    s1 := original.Skip(-1)
+    s2 := original.Skip(0)
+    s3 := original.Skip(1)
+    s4 := original.Skip(5)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // [1 2 3 4]
+    // [1 2 3 4]
+    // [2 3 4]
+    // []
+}
+```
+
+### <span id="Limit">Limit</span>
+
+<p>Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Limit(maxSize int) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4})
+
+    s1 := original.Limit(-1)
+    s2 := original.Limit(0)
+    s3 := original.Limit(1)
+    s4 := original.Limit(5)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // []
+    // []
+    // [1]
+    // [1 2 3 4]
+}
+```
+
+### <span id="Reverse">Reverse</span>
+
+<p>Returns a stream whose elements are reverse order of given stream. <b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Reverse() stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    reverse := original.Reverse()
+
+    fmt.Println(reverse.ToSlice())
+
+    // Output:
+    // [3 2 1]
+}
+```
+
+### <span id="Range">Range</span>
+
+<p>Returns a stream whose elements are in the range from start(included) to end(excluded) original stream.<b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Range(start, end int) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    s1 := original.Range(0, 0)
+    s2 := original.Range(0, 1)
+    s3 := original.Range(0, 3)
+    s4 := original.Range(1, 2)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // []
+    // [1]
+    // [1 2 3]
+    // [2]
+}
+```
+
+### <span id="Sorted">Sorted</span>
+
+<p>Returns a stream consisting of the elements of this stream, sorted according to the provided less function.<b>Support chainable operation</b></p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Sorted(less func(a, b T) bool) stream[T]
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    sorted := original.Sorted(func(a, b int) bool { return a < b })
+
+    fmt.Println(original.ToSlice())
+    fmt.Println(sorted.ToSlice())
+
+    // Output:
+    // [4 2 1 3]
+    // [1 2 3 4]
+}
+```
+
+### <span id="ForEach">ForEach</span>
+
+<p>Performs an action for each element of this stream.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) ForEach(action func(item T))
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result := 0
+    original.ForEach(func(item int) {
+        result += item
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 6
+}
+```
+
+### <span id="Reduce">Reduce</span>
+
+<p>Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an Optional describing the reduced value, if any.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result := original.Reduce(0, func(a, b int) int {
+        return a + b
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 6
+}
+```
+
+### <span id="FindFirst">FindFirst</span>
+
+<p>Returns the first element of this stream and true, or zero value and false if the stream is empty.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) FindFirst() (T, bool)
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result, ok := original.FindFirst()
+
+    fmt.Println(result)
+    fmt.Println(ok)
+
+    // Output:
+    // 1
+    // true
+}
+```
+
+### <span id="Max">Max</span>
+
+<p>Returns the maximum element of this stream according to the provided less function. less fuction: a > b</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Max(less func(a, b T) bool) (T, bool)
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    max, ok := original.Max(func(a, b int) bool { return a > b })
+
+    fmt.Println(max)
+    fmt.Println(ok)
+
+    // Output:
+    // 4
+    // true
+}
+```
+
+### <span id="Min">Min</span>
+
+<p>Returns the minimum element of this stream according to the provided less function. less fuction: a < b</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Min(less func(a, b T) bool) (T, bool)
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    min, ok := original.Min(func(a, b int) bool { return a < b })
+
+    fmt.Println(min)
+    fmt.Println(ok)
+
+    // Output:
+    // 1
+    // true
+}
+```
+
+### <span id="AllMatch">AllMatch</span>
+
+<p>Returns whether all elements of this stream match the provided predicate.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) AllMatch(predicate func(item T) bool) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.AllMatch(func(item int) bool {
+        return item > 0
+    })
+
+    result2 := original.AllMatch(func(item int) bool {
+        return item > 1
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="AnyMatch">AnyMatch</span>
+
+<p>Returns whether any elements of this stream match the provided predicate.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) AnyMatch(predicate func(item T) bool) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.AnyMatch(func(item int) bool {
+        return item > 1
+    })
+
+    result2 := original.AnyMatch(func(item int) bool {
+        return item > 3
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="NoneMatch">NoneMatch</span>
+
+<p>Returns whether no elements of this stream match the provided predicate.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) NoneMatch(predicate func(item T) bool) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.NoneMatch(func(item int) bool {
+        return item > 3
+    })
+
+    result2 := original.NoneMatch(func(item int) bool {
+        return item > 1
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="Count">Count</span>
+
+<p>Returns the count of elements in the stream.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) Count() int
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s1 := stream.FromSlice([]int{1, 2, 3})
+    s2 := stream.FromSlice([]int{})
+
+    fmt.Println(s1.Count())
+    fmt.Println(s2.Count())
+
+    // Output:
+    // 3
+    // 0
+}
+```
+
+### <span id="ToSlice">ToSlice</span>
+
+<p>Returns the elements in the stream.</p>
+
+<b>Signature:</b>
+
+```go
+func (s stream[T]) ToSlice() []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.Of(1, 2, 3)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```

docs/stream_zh-CN.md

@@ -0,0 +1,907 @@
+# Strutil
+
+Stream 实现，该包仅验证简单 go stream 实现，功能有限。
+
+<div STYLE="page-break-after: always;"></div>
+
+## 源码:
+
+-   [https://github.com/duke-git/lancet/blob/main/stream/stream.go](https://github.com/duke-git/lancet/blob/main/stream/stream.go)
+
+<div STYLE="page-break-after: always;"></div>
+
+## 用法:
+
+```go
+import (
+    "github.com/duke-git/lancet/v2/stream"
+)
+```
+
+<div STYLE="page-break-after: always;"></div>
+
+## 目录
+
+-   [Of](#Of)
+-   [FromSlice](#FromSlice)
+-   [FromChannel](#FromChannel)
+-   [FromRange](#FromRange)
+-   [Generate](#Generate)
+-   [Concat](#Concat)
+-   [Distinct](#Distinct)
+-   [Filter](#Filter)
+-   [Map](#Map)
+-   [Peek](#Peek)
+-   [Skip](#Skip)
+-   [Limit](#Limit)
+-   [Reverse](#Reverse)
+-   [Range](#Range)
+-   [Sorted](#Sorted)
+-   [ForEach](#ForEach)
+-   [Reduce](#Reduce)
+-   [FindFirst](#FindFirst)
+-   [Max](#Max)
+-   [Min](#Min)
+-   [AllMatch](#AllMatch)
+-   [AnyMatch](#AnyMatch)
+-   [NoneMatch](#NoneMatch)
+-   [Count](#Count)
+-   [ToSlice](#ToSlice)
+
+<div STYLE="page-break-after: always;"></div>
+
+## 文档
+
+### <span id="Of">Of</span>
+
+<p>创建元素为指定值的stream。</p>
+
+<b>函数签名:</b>
+
+```go
+func Of[T any](elems ...T) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.Of(1, 2, 3)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromSlice">FromSlice</span>
+
+<p>从切片创建stream。</p>
+
+<b>函数签名:</b>
+
+```go
+func FromSlice[T any](source []T) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.FromSlice([]int{1, 2, 3})
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromChannel">FromChannel</span>
+
+<p>从通道创建stream。</p>
+
+<b>函数签名:</b>
+
+```go
+func FromChannel[T any](source <-chan T) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    ch := make(chan int)
+    go func() {
+        for i := 1; i < 4; i++ {
+            ch <- i
+        }
+        close(ch)
+    }()
+
+    s := stream.FromChannel(ch)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="FromRange">FromRange</span>
+
+<p>指定一个范围创建stream, 范围两端点值都包括在内。</p>
+
+<b>函数签名:</b>
+
+```go
+func FromRange[T constraints.Integer | constraints.Float](start, end, step T) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.FromRange(1, 5, 1)
+
+    data := s.ToSlice()
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3 4 5]
+}
+```
+
+### <span id="Generate">Generate</span>
+
+<p>创建一个stream，其中每个元素都由提供的生成器函数生成</p>
+
+<b>函数签名:</b>
+
+```go
+func Generate[T any](generator func() func() (item T, ok bool)) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    n := 0
+    max := 4
+
+    generator := func() func() (int, bool) {
+        return func() (int, bool) {
+            n++
+            return n, n < max
+        }
+    }
+
+    s := stream.Generate(generator)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```
+
+### <span id="Concat">Concat</span>
+
+<p>创建一个延迟连接stream，其元素是第一个stream的所有元素，后跟第二个stream的全部元素。</p>
+
+<b>函数签名:</b>
+
+```go
+func Concat[T any](a, b stream[T]) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s1 := stream.FromSlice([]int{1, 2, 3})
+    s2 := stream.FromSlice([]int{4, 5, 6})
+
+    s := Concat(s1, s2)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3 4 5 6]
+}
+```
+
+### <span id="Distinct">Distinct</span>
+
+<p>创建并返回一个stream，用于删除重复的项。 <b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Distinct() stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 2, 3, 3, 3})
+    distinct := original.Distinct()
+
+    data1 := original.ToSlice()
+    data2 := distinct.ToSlice()
+
+    fmt.Println(data1)
+    fmt.Println(data2)
+
+    // Output:
+    // [1 2 2 3 3 3]
+    // [1 2 3]
+}
+```
+
+### <span id="Filter">Filter</span>
+
+<p>返回一个通过判定函数的stream <b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Filter(predicate func(item T) bool) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4, 5})
+
+    isEven := func(n int) bool {
+        return n%2 == 0
+    }
+
+    even := original.Filter(isEven)
+
+    fmt.Println(even.ToSlice())
+
+    // Output:
+    // [2 4]
+}
+```
+
+### <span id="Map">Map</span>
+
+<p>返回一个stream，该stream由将给定函数应用于源stream元素的元素组成。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Map(mapper func(item T) T) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    addOne := func(n int) int {
+        return n + 1
+    }
+
+    increament := original.Map(addOne)
+
+    fmt.Println(increament.ToSlice())
+
+    // Output:
+    // [2 3 4]
+}
+```
+
+### <span id="Peek">Peek</span>
+
+<p>返回一个由源stream的元素组成的stream，并在从生成的stream中消耗元素时对每个元素执行所提供的操作。 <b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Peek(consumer func(item T)) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    data := []string{}
+    peekStream := original.Peek(func(n int) {
+        data = append(data, fmt.Sprint("value", n))
+    })
+
+    fmt.Println(original.ToSlice())
+    fmt.Println(peekStream.ToSlice())
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+    // [1 2 3]
+    // [value1 value2 value3]
+}
+```
+
+### <span id="Skip">Skip</span>
+
+<p>在丢弃stream的前n个元素后，返回由源stream的其余元素组成的stream。如果此stream包含的元素少于n个，则将返回一个空stream。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Skip(n int) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4})
+
+    s1 := original.Skip(-1)
+    s2 := original.Skip(0)
+    s3 := original.Skip(1)
+    s4 := original.Skip(5)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // [1 2 3 4]
+    // [1 2 3 4]
+    // [2 3 4]
+    // []
+}
+```
+
+### <span id="Limit">Limit</span>
+
+<p>返回由源stream的元素组成的stream，该stream被截断为长度不超过maxSize。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Limit(maxSize int) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3, 4})
+
+    s1 := original.Limit(-1)
+    s2 := original.Limit(0)
+    s3 := original.Limit(1)
+    s4 := original.Limit(5)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // []
+    // []
+    // [1]
+    // [1 2 3 4]
+}
+```
+
+### <span id="Reverse">Reverse</span>
+
+<p>返回元素与源stream的顺序相反的stream。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Reverse() stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    reverse := original.Reverse()
+
+    fmt.Println(reverse.ToSlice())
+
+    // Output:
+    // [3 2 1]
+}
+```
+
+### <span id="Range">Range</span>
+
+<p>返回一个stream，该stream的元素在从源stream的开始（包含）到结束（排除）的范围内。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Range(start, end int) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    s1 := original.Range(0, 0)
+    s2 := original.Range(0, 1)
+    s3 := original.Range(0, 3)
+    s4 := original.Range(1, 2)
+
+    fmt.Println(s1.ToSlice())
+    fmt.Println(s2.ToSlice())
+    fmt.Println(s3.ToSlice())
+    fmt.Println(s4.ToSlice())
+
+    // Output:
+    // []
+    // [1]
+    // [1 2 3]
+    // [2]
+}
+```
+
+### <span id="Sorted">Sorted</span>
+
+<p>返回一个stream，该stream由源stream的元素组成，并根据提供的less函数进行排序。<b>支持链式操作</b></p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Sorted(less func(a, b T) bool) stream[T]
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    sorted := original.Sorted(func(a, b int) bool { return a < b })
+
+    fmt.Println(original.ToSlice())
+    fmt.Println(sorted.ToSlice())
+
+    // Output:
+    // [4 2 1 3]
+    // [1 2 3 4]
+}
+```
+
+### <span id="ForEach">ForEach</span>
+
+<p>对stream的每个元素执行一个操作。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) ForEach(action func(item T))
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result := 0
+    original.ForEach(func(item int) {
+        result += item
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 6
+}
+```
+
+### <span id="Reduce">Reduce</span>
+
+<p>使用关联累加函数对stream的元素执行reduce操作，并reduce操作结果（如果有）。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result := original.Reduce(0, func(a, b int) int {
+        return a + b
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // 6
+}
+```
+
+### <span id="FindFirst">FindFirst</span>
+
+<p>返回此stream的第一个元素和true，如果stream为空，则返回零值和false。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) FindFirst() (T, bool)
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result, ok := original.FindFirst()
+
+    fmt.Println(result)
+    fmt.Println(ok)
+
+    // Output:
+    // 1
+    // true
+}
+```
+
+### <span id="Max">Max</span>
+
+<p>根据提供的less函数返回stream的最大元素。less 函数: a > b</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Max(less func(a, b T) bool) (T, bool)
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    max, ok := original.Max(func(a, b int) bool { return a > b })
+
+    fmt.Println(max)
+    fmt.Println(ok)
+
+    // Output:
+    // 4
+    // true
+}
+```
+
+### <span id="Min">Min</span>
+
+<p>根据提供的less函数返回stream的最小元素。less函数: a < b</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Min(less func(a, b T) bool) (T, bool)
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{4, 2, 1, 3})
+
+    min, ok := original.Min(func(a, b int) bool { return a < b })
+
+    fmt.Println(min)
+    fmt.Println(ok)
+
+    // Output:
+    // 1
+    // true
+}
+```
+
+### <span id="AllMatch">AllMatch</span>
+
+<p>判断stream的所有元素是否全部匹配指定判定函数。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) AllMatch(predicate func(item T) bool) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.AllMatch(func(item int) bool {
+        return item > 0
+    })
+
+    result2 := original.AllMatch(func(item int) bool {
+        return item > 1
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="AnyMatch">AnyMatch</span>
+
+<p>判断stream是否包含匹配指定判定函数的元素。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) AnyMatch(predicate func(item T) bool) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.AnyMatch(func(item int) bool {
+        return item > 1
+    })
+
+    result2 := original.AnyMatch(func(item int) bool {
+        return item > 3
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="NoneMatch">NoneMatch</span>
+
+<p>判断stream的元素是否全部不匹配指定的判定函数。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) NoneMatch(predicate func(item T) bool) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    original := stream.FromSlice([]int{1, 2, 3})
+
+    result1 := original.NoneMatch(func(item int) bool {
+        return item > 3
+    })
+
+    result2 := original.NoneMatch(func(item int) bool {
+        return item > 1
+    })
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="Count">Count</span>
+
+<p>返回stream中元素的数量。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) Count() int
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s1 := stream.FromSlice([]int{1, 2, 3})
+    s2 := stream.FromSlice([]int{})
+
+    fmt.Println(s1.Count())
+    fmt.Println(s2.Count())
+
+    // Output:
+    // 3
+    // 0
+}
+```
+
+### <span id="ToSlice">ToSlice</span>
+
+<p>返回stream中的元素切片。</p>
+
+<b>函数签名:</b>
+
+```go
+func (s stream[T]) ToSlice() []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/stream"
+)
+
+func main() {
+    s := stream.Of(1, 2, 3)
+
+    data := s.ToSlice()
+
+    fmt.Println(data)
+
+    // Output:
+    // [1 2 3]
+}
+```

fileutil/file.go

@@ -15,6 +15,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"runtime"
 	"strings"
 )
 
@@ -345,3 +346,15 @@ func MiMeType(file any) string {
 	}
 	return mediatype
 }
+
+// CurrentPath return current absolute path.
+// Play: todo
+func CurrentPath() string {
+	var absPath string
+	_, filename, _, ok := runtime.Caller(1)
+	if ok {
+		absPath = path.Dir(filename)
+	}
+
+	return absPath
+}

fileutil/file_test.go

@@ -241,3 +241,8 @@ func TestListFileNames(t *testing.T) {
 	expected := []string{"formatter.go", "formatter_example_test.go", "formatter_test.go"}
 	assert.Equal(expected, filesInPath)
 }
+
+func TestCurrentPath(t *testing.T) {
+	absPath := CurrentPath()
+	t.Log(absPath)
+}

formatter/formatter.go

@@ -6,10 +6,10 @@ package formatter
 
 import (
 	"fmt"
-	"reflect"
-	"strconv"
-	"strings"
 
+	"github.com/duke-git/lancet/v2/convertor"
+	"github.com/duke-git/lancet/v2/strutil"
+	"github.com/duke-git/lancet/v2/validator"
 	"golang.org/x/exp/constraints"
 )
 
@@ -18,54 +18,29 @@ import (
 // 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 validator.IsInt(value) {
-	if err != nil {
+		v, err := convertor.ToInt(value)
+		if err != nil {
+			return ""
+		}
+		return symbol + commaInt(v)
+	}
+
+	if validator.IsFloat(value) {
+		v, err := convertor.ToFloat(value)
+		if err != nil {
+			return ""
+		}
+		return symbol + commaFloat(v)
+	}
+
+	if strutil.IsString(value) {
+		v := fmt.Sprintf("%v", value)
+		if validator.IsNumberStr(v) {
+			return symbol + commaStr(v)
+		}
 		return ""
 	}
 
-	dotIndex := strings.Index(s, ".")
+	return ""
-	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_internal.go

@@ -0,0 +1,85 @@
+package formatter
+
+import (
+	"bytes"
+	"math"
+	"strconv"
+	"strings"
+)
+
+// see https://github.com/dustin/go-humanize/blob/master/comma.go
+func commaInt(v int64) string {
+	sign := ""
+
+	// Min int64 can't be negated to a usable value, so it has to be special cased.
+	if v == math.MinInt64 {
+		return "-9,223,372,036,854,775,808"
+	}
+
+	if v < 0 {
+		sign = "-"
+		v = 0 - v
+	}
+
+	parts := []string{"", "", "", "", "", "", ""}
+	j := len(parts) - 1
+
+	for v > 999 {
+		parts[j] = strconv.FormatInt(v%1000, 10)
+		switch len(parts[j]) {
+		case 2:
+			parts[j] = "0" + parts[j]
+		case 1:
+			parts[j] = "00" + parts[j]
+		}
+		v = v / 1000
+		j--
+	}
+	parts[j] = strconv.Itoa(int(v))
+	return sign + strings.Join(parts[j:], ",")
+}
+
+func commaFloat(v float64) string {
+	buf := &bytes.Buffer{}
+	if v < 0 {
+		buf.Write([]byte{'-'})
+		v = 0 - v
+	}
+
+	comma := []byte{','}
+
+	parts := strings.Split(strconv.FormatFloat(v, 'f', -1, 64), ".")
+	pos := 0
+	if len(parts[0])%3 != 0 {
+		pos += len(parts[0]) % 3
+		buf.WriteString(parts[0][:pos])
+		buf.Write(comma)
+	}
+	for ; pos < len(parts[0]); pos += 3 {
+		buf.WriteString(parts[0][pos : pos+3])
+		buf.Write(comma)
+	}
+	buf.Truncate(buf.Len() - 1)
+
+	if len(parts) > 1 {
+		buf.Write([]byte{'.'})
+		buf.WriteString(parts[1])
+	}
+	return buf.String()
+}
+
+func commaStr(s string) string {
+	dotIndex := strings.Index(s, ".")
+	if dotIndex != -1 {
+		return commaStrRecursive(s[:dotIndex]) + s[dotIndex:]
+	}
+
+	return commaStrRecursive(s)
+}
+
+func commaStrRecursive(s string) string {
+	if len(s) <= 3 {
+		return s
+	}
+	return commaStrRecursive(s[:len(s)-3]) + "," + commaStrRecursive(s[len(s)-3:])
+}

formatter/formatter_test.go

@@ -16,12 +16,13 @@ func TestComma(t *testing.T) {
 	assert.Equal("12,345", Comma("12345", ""))
 	assert.Equal("12,345.6789", Comma("12345.6789", ""))
 	assert.Equal("123,456,789,000", Comma("123456789000", ""))
+	assert.Equal("12,345,678.9", Comma("12345678.9", ""))
 
 	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("12,345,678.9", Comma(12345678.9, ""))
 	assert.Equal("123,456,789,000", Comma(123456789000, ""))
 }

mathutil/mathutil.go

@@ -218,21 +218,21 @@ func RangeWithStep[T constraints.Integer | constraints.Float](start, end, step T
 }
 
 // AngleToRadian converts angle value to radian value.
-// Play: todo
+// Play: https://go.dev/play/p/CIvlICqrHql
 func AngleToRadian(angle float64) float64 {
 	radian := angle * (math.Pi / 180)
 	return radian
 }
 
 // RadianToAngle converts radian value to angle value.
-// Play: todo
+// Play: https://go.dev/play/p/dQtmOTUOMgi
 func RadianToAngle(radian float64) float64 {
 	angle := radian * (180 / math.Pi)
 	return angle
 }
 
 // PointDistance get two points distance.
-// Play: todo
+// Play: https://go.dev/play/p/RrG4JIaziM8
 func PointDistance(x1, y1, x2, y2 float64) float64 {
 	a := x1 - x2
 	b := y1 - y2
@@ -242,7 +242,7 @@ func PointDistance(x1, y1, x2, y2 float64) float64 {
 }
 
 // IsPrimes checks if number is prime number.
-// Play: todo
+// Play: https://go.dev/play/p/Rdd8UTHZJ7u
 func IsPrime(n int) bool {
 	if n < 2 {
 		return false

slice/slice.go

@@ -492,6 +492,30 @@ func Reduce[T any](slice []T, iteratee func(index int, item1, item2 T) T, initia
 	return result
 }
 
+// ReduceBy produces a value from slice by accumulating the result of each element as passed through the reducer function.
+// Play: todo
+func ReduceBy[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U {
+	accumulator := initial
+
+	for i, v := range slice {
+		accumulator = reducer(i, v, accumulator)
+	}
+
+	return accumulator
+}
+
+// ReduceRight is like ReduceBy, but it iterates over elements of slice from right to left.
+// Play: todo
+func ReduceRight[T any, U any](slice []T, initial U, reducer func(index int, item T, agg U) U) U {
+	accumulator := initial
+
+	for i := len(slice) - 1; i >= 0; i-- {
+		accumulator = reducer(i, slice[i], accumulator)
+	}
+
+	return accumulator
+}
+
 // Replace returns a copy of the slice with the first n non-overlapping instances of old replaced by new.
 // Play: https://go.dev/play/p/P5mZp7IhOFo
 func Replace[T comparable](slice []T, old T, new T, n int) []T {

slice/slice_example_test.go

@@ -460,6 +460,34 @@ func ExampleReduce() {
 	// 6
 }
 
+func ExampleReduceBy() {
+	result1 := ReduceBy([]int{1, 2, 3, 4}, 0, func(_ int, item int, agg int) int {
+		return agg + item
+	})
+
+	result2 := ReduceBy([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+		return agg + fmt.Sprintf("%v", item)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// 10
+	// 1234
+}
+
+func ExampleReduceRight() {
+	result := ReduceRight([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+		return agg + fmt.Sprintf("%v", item)
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// 4321
+}
+
 func ExampleReplace() {
 	strs := []string{"a", "b", "c", "a"}
 

slice/slice_test.go

@@ -405,6 +405,32 @@ func TestReduce(t *testing.T) {
 	}
 }
 
+func TestReduceBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestReduceBy")
+
+	result1 := ReduceBy([]int{1, 2, 3, 4}, 0, func(_ int, item int, agg int) int {
+		return agg + item
+	})
+
+	result2 := ReduceBy([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+		return agg + fmt.Sprintf("%v", item)
+	})
+
+	assert.Equal(10, result1)
+	assert.Equal("1234", result2)
+
+}
+
+func TestReduceRight(t *testing.T) {
+	assert := internal.NewAssert(t, "ReduceRight")
+
+	result := ReduceRight([]int{1, 2, 3, 4}, "", func(_ int, item int, agg string) string {
+		return agg + fmt.Sprintf("%v", item)
+	})
+
+	assert.Equal("4321", result)
+}
+
 func TestIntSlice(t *testing.T) {
 	var nums []any
 	nums = append(nums, 1, 2, 3)

stream/stream.go

@@ -1,9 +1,8 @@
 // Copyright 2023 dudaodong@gmail.com. All rights resulterved.
 // Use of this source code is governed by MIT license
 
-// Package stream implements a sequence of elements supporting sequential and parallel aggregate operations.
+// Package stream implements a sequence of elements supporting sequential and operations.
-// this package is an experiment to explore if stream in go can work as the way java does. it's complete, but not
+// this package is an experiment to explore if stream in go can work as the way java does. it's function is very limited.
-// powerful like other libs
 package stream
 
 import (
@@ -52,13 +51,14 @@ type stream[T any] struct {
 	source []T
 }
 
-// Of creates a stream stream whose elements are the specified values.
+// Of creates a stream whose elements are the specified values.
+// Play: https://go.dev/play/p/jI6_iZZuVFE
 func Of[T any](elems ...T) stream[T] {
 	return FromSlice(elems)
 }
 
 // Generate stream where each element is generated by the provided generater function
-// generater function: func() func() (item T, ok bool) {}
+// Play: https://go.dev/play/p/rkOWL1yA3j9
 func Generate[T any](generator func() func() (item T, ok bool)) stream[T] {
 	source := make([]T, 0)
 
@@ -75,11 +75,13 @@ func Generate[T any](generator func() func() (item T, ok bool)) stream[T] {
 }
 
 // FromSlice creates stream from slice.
+// Play: https://go.dev/play/p/wywTO0XZtI4
 func FromSlice[T any](source []T) stream[T] {
 	return stream[T]{source: source}
 }
 
 // FromChannel creates stream from channel.
+// Play: https://go.dev/play/p/9TZYugGMhXZ
 func FromChannel[T any](source <-chan T) stream[T] {
 	s := make([]T, 0)
 
@@ -91,6 +93,7 @@ func FromChannel[T any](source <-chan T) stream[T] {
 }
 
 // FromRange creates a number stream from start to end. both start and end are included. [start, end]
+// Play: https://go.dev/play/p/9Ex1-zcg-B-
 func FromRange[T constraints.Integer | constraints.Float](start, end, step T) stream[T] {
 	if end < start {
 		panic("stream.FromRange: param start should be before param end")
@@ -109,6 +112,7 @@ func FromRange[T constraints.Integer | constraints.Float](start, end, step T) st
 }
 
 // Concat creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream.
+// Play: https://go.dev/play/p/HM4OlYk_OUC
 func Concat[T any](a, b stream[T]) stream[T] {
 	source := make([]T, 0)
 
@@ -119,6 +123,7 @@ func Concat[T any](a, b stream[T]) stream[T] {
 }
 
 // Distinct returns a stream that removes the duplicated items.
+// Play: https://go.dev/play/p/eGkOSrm64cB
 func (s stream[T]) Distinct() stream[T] {
 	source := make([]T, 0)
 
@@ -147,6 +152,7 @@ func hashKey(data any) string {
 }
 
 // Filter returns a stream consisting of the elements of this stream that match the given predicate.
+// Play: https://go.dev/play/p/MFlSANo-buc
 func (s stream[T]) Filter(predicate func(item T) bool) stream[T] {
 	source := make([]T, 0)
 
@@ -160,6 +166,7 @@ func (s stream[T]) Filter(predicate func(item T) bool) stream[T] {
 }
 
 // Map returns a stream consisting of the elements of this stream that apply the given function to elements of stream.
+// Play: https://go.dev/play/p/OtNQUImdYko
 func (s stream[T]) Map(mapper func(item T) T) stream[T] {
 	source := make([]T, s.Count())
 
@@ -171,6 +178,7 @@ func (s stream[T]) Map(mapper func(item T) T) stream[T] {
 }
 
 // Peek returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.
+// Play: https://go.dev/play/p/u1VNzHs6cb2
 func (s stream[T]) Peek(consumer func(item T)) stream[T] {
 	for _, v := range s.source {
 		consumer(v)
@@ -181,6 +189,7 @@ func (s stream[T]) Peek(consumer func(item T)) stream[T] {
 
 // Skip returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream.
 // If this stream contains fewer than n elements then an empty stream will be returned.
+// Play: https://go.dev/play/p/fNdHbqjahum
 func (s stream[T]) Skip(n int) stream[T] {
 	if n <= 0 {
 		return s
@@ -201,6 +210,7 @@ func (s stream[T]) Skip(n int) stream[T] {
 }
 
 // Limit returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length.
+// Play: https://go.dev/play/p/qsO4aniDcGf
 func (s stream[T]) Limit(maxSize int) stream[T] {
 	if s.source == nil {
 		return s
@@ -220,6 +230,7 @@ func (s stream[T]) Limit(maxSize int) stream[T] {
 }
 
 // AllMatch returns whether all elements of this stream match the provided predicate.
+// Play: https://go.dev/play/p/V5TBpVRs-Cx
 func (s stream[T]) AllMatch(predicate func(item T) bool) bool {
 	for _, v := range s.source {
 		if !predicate(v) {
@@ -231,6 +242,7 @@ func (s stream[T]) AllMatch(predicate func(item T) bool) bool {
 }
 
 // AnyMatch returns whether any elements of this stream match the provided predicate.
+// Play: https://go.dev/play/p/PTCnWn4OxSn
 func (s stream[T]) AnyMatch(predicate func(item T) bool) bool {
 	for _, v := range s.source {
 		if predicate(v) {
@@ -242,11 +254,13 @@ func (s stream[T]) AnyMatch(predicate func(item T) bool) bool {
 }
 
 // NoneMatch returns whether no elements of this stream match the provided predicate.
+// Play: https://go.dev/play/p/iWS64pL1oo3
 func (s stream[T]) NoneMatch(predicate func(item T) bool) bool {
 	return !s.AnyMatch(predicate)
 }
 
 // ForEach performs an action for each element of this stream.
+// Play: https://go.dev/play/p/Dsm0fPqcidk
 func (s stream[T]) ForEach(action func(item T)) {
 	for _, v := range s.source {
 		action(v)
@@ -254,20 +268,23 @@ func (s stream[T]) ForEach(action func(item T)) {
 }
 
 // Reduce performs a reduction on the elements of this stream, using an associative accumulation function, and returns an Optional describing the reduced value, if any.
-func (s stream[T]) Reduce(init T, accumulator func(a, b T) T) T {
+// Play: https://go.dev/play/p/6uzZjq_DJLU
+func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T {
 	for _, v := range s.source {
-		init = accumulator(init, v)
+		initial = accumulator(initial, v)
 	}
 
-	return init
+	return initial
 }
 
 // Count returns the count of elements in the stream.
+// Play: https://go.dev/play/p/r3koY6y_Xo-
 func (s stream[T]) Count() int {
 	return len(s.source)
 }
 
 // FindFirst returns the first element of this stream and true, or zero value and false if the stream is empty.
+// Play: https://go.dev/play/p/9xEf0-6C1e3
 func (s stream[T]) FindFirst() (T, bool) {
 	var result T
 
@@ -279,6 +296,7 @@ func (s stream[T]) FindFirst() (T, bool) {
 }
 
 // Reverse returns a stream whose elements are reverse order of given stream.
+// Play: https://go.dev/play/p/A8_zkJnLHm4
 func (s stream[T]) Reverse() stream[T] {
 	l := len(s.source)
 	source := make([]T, l)
@@ -290,6 +308,7 @@ func (s stream[T]) Reverse() stream[T] {
 }
 
 // Range returns a stream whose elements are in the range from start(included) to end(excluded) original stream.
+// Play: https://go.dev/play/p/indZY5V2f4j
 func (s stream[T]) Range(start, end int) stream[T] {
 	if start < 0 {
 		start = 0
@@ -315,6 +334,7 @@ func (s stream[T]) Range(start, end int) stream[T] {
 }
 
 // Sorted returns a stream consisting of the elements of this stream, sorted according to the provided less function.
+// Play: https://go.dev/play/p/XXtng5uonFj
 func (s stream[T]) Sorted(less func(a, b T) bool) stream[T] {
 	source := []T{}
 	source = append(source, s.source...)
@@ -326,6 +346,7 @@ func (s stream[T]) Sorted(less func(a, b T) bool) stream[T] {
 
 // Max returns the maximum element of this stream according to the provided less function.
 // less: a > b
+// Play: https://go.dev/play/p/fm-1KOPtGzn
 func (s stream[T]) Max(less func(a, b T) bool) (T, bool) {
 	var max T
 
@@ -343,6 +364,7 @@ func (s stream[T]) Max(less func(a, b T) bool) (T, bool) {
 
 // Min returns the minimum element of this stream according to the provided less function.
 // less: a < b
+// Play: https://go.dev/play/p/vZfIDgGNRe_0
 func (s stream[T]) Min(less func(a, b T) bool) (T, bool) {
 	var min T
 
@@ -360,6 +382,7 @@ func (s stream[T]) Min(less func(a, b T) bool) (T, bool) {
 }
 
 // ToSlice return the elements in the stream.
+// Play: https://go.dev/play/p/jI6_iZZuVFE
 func (s stream[T]) ToSlice() []T {
 	return s.source
 }

stream/stream_example_test.go

@@ -0,0 +1,373 @@
+package stream
+
+import (
+	"fmt"
+)
+
+func ExampleOf() {
+	s := Of(1, 2, 3)
+
+	data := s.ToSlice()
+
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3]
+}
+
+func ExampleFromSlice() {
+	s := FromSlice([]int{1, 2, 3})
+
+	data := s.ToSlice()
+
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3]
+}
+
+func ExampleFromChannel() {
+	ch := make(chan int)
+	go func() {
+		for i := 1; i < 4; i++ {
+			ch <- i
+		}
+		close(ch)
+	}()
+
+	s := FromChannel(ch)
+
+	data := s.ToSlice()
+
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3]
+}
+
+func ExampleFromRange() {
+	s := FromRange(1, 5, 1)
+
+	data := s.ToSlice()
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3 4 5]
+}
+
+func ExampleGenerate() {
+	n := 0
+	max := 4
+
+	generator := func() func() (int, bool) {
+		return func() (int, bool) {
+			n++
+			return n, n < max
+		}
+	}
+
+	s := Generate(generator)
+
+	data := s.ToSlice()
+
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3]
+}
+
+func ExampleConcat() {
+	s1 := FromSlice([]int{1, 2, 3})
+	s2 := FromSlice([]int{4, 5, 6})
+
+	s := Concat(s1, s2)
+
+	data := s.ToSlice()
+
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3 4 5 6]
+}
+
+func ExampleStream_Distinct() {
+	original := FromSlice([]int{1, 2, 2, 3, 3, 3})
+	distinct := original.Distinct()
+
+	data1 := original.ToSlice()
+	data2 := distinct.ToSlice()
+
+	fmt.Println(data1)
+	fmt.Println(data2)
+
+	// Output:
+	// [1 2 2 3 3 3]
+	// [1 2 3]
+}
+
+func ExampleStream_Filter() {
+	original := FromSlice([]int{1, 2, 3, 4, 5})
+
+	isEven := func(n int) bool {
+		return n%2 == 0
+	}
+
+	even := original.Filter(isEven)
+
+	fmt.Println(even.ToSlice())
+
+	// Output:
+	// [2 4]
+}
+
+func ExampleStream_Map() {
+	original := FromSlice([]int{1, 2, 3})
+
+	addOne := func(n int) int {
+		return n + 1
+	}
+
+	increament := original.Map(addOne)
+
+	fmt.Println(increament.ToSlice())
+
+	// Output:
+	// [2 3 4]
+}
+
+func ExampleStream_Peek() {
+	original := FromSlice([]int{1, 2, 3})
+
+	data := []string{}
+	peekStream := original.Peek(func(n int) {
+		data = append(data, fmt.Sprint("value", n))
+	})
+
+	fmt.Println(original.ToSlice())
+	fmt.Println(peekStream.ToSlice())
+	fmt.Println(data)
+
+	// Output:
+	// [1 2 3]
+	// [1 2 3]
+	// [value1 value2 value3]
+}
+
+func ExampleStream_Skip() {
+	original := FromSlice([]int{1, 2, 3, 4})
+
+	s1 := original.Skip(-1)
+	s2 := original.Skip(0)
+	s3 := original.Skip(1)
+	s4 := original.Skip(5)
+
+	fmt.Println(s1.ToSlice())
+	fmt.Println(s2.ToSlice())
+	fmt.Println(s3.ToSlice())
+	fmt.Println(s4.ToSlice())
+
+	// Output:
+	// [1 2 3 4]
+	// [1 2 3 4]
+	// [2 3 4]
+	// []
+}
+
+func ExampleStream_Limit() {
+	original := FromSlice([]int{1, 2, 3, 4})
+
+	s1 := original.Limit(-1)
+	s2 := original.Limit(0)
+	s3 := original.Limit(1)
+	s4 := original.Limit(5)
+
+	fmt.Println(s1.ToSlice())
+	fmt.Println(s2.ToSlice())
+	fmt.Println(s3.ToSlice())
+	fmt.Println(s4.ToSlice())
+
+	// Output:
+	// []
+	// []
+	// [1]
+	// [1 2 3 4]
+}
+
+func ExampleStream_AllMatch() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result1 := original.AllMatch(func(item int) bool {
+		return item > 0
+	})
+
+	result2 := original.AllMatch(func(item int) bool {
+		return item > 1
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleStream_AnyMatch() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result1 := original.AnyMatch(func(item int) bool {
+		return item > 1
+	})
+
+	result2 := original.AnyMatch(func(item int) bool {
+		return item > 3
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleStream_NoneMatch() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result1 := original.NoneMatch(func(item int) bool {
+		return item > 3
+	})
+
+	result2 := original.NoneMatch(func(item int) bool {
+		return item > 1
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleStream_ForEach() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result := 0
+	original.ForEach(func(item int) {
+		result += item
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// 6
+}
+
+func ExampleStream_Reduce() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result := original.Reduce(0, func(a, b int) int {
+		return a + b
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// 6
+}
+
+func ExampleStream_FindFirst() {
+	original := FromSlice([]int{1, 2, 3})
+
+	result, ok := original.FindFirst()
+
+	fmt.Println(result)
+	fmt.Println(ok)
+
+	// Output:
+	// 1
+	// true
+}
+
+func ExampleStream_Reverse() {
+	original := FromSlice([]int{1, 2, 3})
+
+	reverse := original.Reverse()
+
+	fmt.Println(reverse.ToSlice())
+
+	// Output:
+	// [3 2 1]
+}
+
+func ExampleStream_Range() {
+	original := FromSlice([]int{1, 2, 3})
+
+	s1 := original.Range(0, 0)
+	s2 := original.Range(0, 1)
+	s3 := original.Range(0, 3)
+	s4 := original.Range(1, 2)
+
+	fmt.Println(s1.ToSlice())
+	fmt.Println(s2.ToSlice())
+	fmt.Println(s3.ToSlice())
+	fmt.Println(s4.ToSlice())
+
+	// Output:
+	// []
+	// [1]
+	// [1 2 3]
+	// [2]
+}
+
+func ExampleStream_Sorted() {
+	original := FromSlice([]int{4, 2, 1, 3})
+
+	sorted := original.Sorted(func(a, b int) bool { return a < b })
+
+	fmt.Println(original.ToSlice())
+	fmt.Println(sorted.ToSlice())
+
+	// Output:
+	// [4 2 1 3]
+	// [1 2 3 4]
+}
+
+func ExampleStream_Max() {
+	original := FromSlice([]int{4, 2, 1, 3})
+
+	max, ok := original.Max(func(a, b int) bool { return a > b })
+
+	fmt.Println(max)
+	fmt.Println(ok)
+
+	// Output:
+	// 4
+	// true
+}
+
+func ExampleStream_Min() {
+	original := FromSlice([]int{4, 2, 1, 3})
+
+	min, ok := original.Min(func(a, b int) bool { return a < b })
+
+	fmt.Println(min)
+	fmt.Println(ok)
+
+	// Output:
+	// 1
+	// true
+}
+
+func ExampleStream_Count() {
+	s1 := FromSlice([]int{1, 2, 3})
+	s2 := FromSlice([]int{})
+
+	fmt.Println(s1.Count())
+	fmt.Println(s2.Count())
+
+	// Output:
+	// 3
+	// 0
+}

stream/stream_test.go

@@ -147,13 +147,17 @@ func TestStream_Peek(t *testing.T) {
 func TestStream_Skip(t *testing.T) {
 	assert := internal.NewAssert(t, "TestStream_Peek")
 
-	stream := FromSlice([]int{1, 2, 3, 4, 5, 6})
+	stream := FromSlice([]int{1, 2, 3, 4})
 
 	s1 := stream.Skip(-1)
 	s2 := stream.Skip(0)
+	s3 := stream.Skip(1)
+	s4 := stream.Skip(2)
 
-	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s1.ToSlice())
+	assert.Equal([]int{1, 2, 3, 4}, s1.ToSlice())
-	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s2.ToSlice())
+	assert.Equal([]int{1, 2, 3, 4}, s2.ToSlice())
+	assert.Equal([]int{2, 3, 4}, s3.ToSlice())
+	assert.Equal([]int{3, 4}, s4.ToSlice())
 }
 
 func TestStream_Limit(t *testing.T) {
@@ -248,6 +252,16 @@ func TestStream_Reduce(t *testing.T) {
 	assert.Equal(6, result)
 }
 
+func TestStream_Count(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Count")
+
+	s1 := FromSlice([]int{1, 2, 3})
+	s2 := FromSlice([]int{})
+
+	assert.Equal(3, s1.Count())
+	assert.Equal(0, s2.Count())
+}
+
 func TestStream_FindFirst(t *testing.T) {
 	assert := internal.NewAssert(t, "TestStream_FindFirst")
 

strutil/string.go

@@ -362,7 +362,7 @@ func WordCount(s string) int {
 }
 
 // RemoveNonPrintable remove non-printable characters from a string.
-// Play: todo
+// Play: https://go.dev/play/p/og47F5x_jTZ
 func RemoveNonPrintable(str string) string {
 	result := strings.Map(func(r rune) rune {
 		if unicode.IsPrint(r) {

validator/validator.go

@@ -59,7 +59,7 @@ func IsAllLower(str string) bool {
 }
 
 // IsASCII checks if string is all ASCII char.
-// Play: todo
+// Play: https://go.dev/play/p/hfQNPLX0jNa
 func IsASCII(str string) bool {
 	for i := 0; i < len(str); i++ {
 		if str[i] > unicode.MaxASCII {
@@ -70,7 +70,7 @@ func IsASCII(str string) bool {
 }
 
 // IsPrintable checks if string is all printable chars.
-// Play: todo
+// Play: https://go.dev/play/p/Pe1FE2gdtTP
 func IsPrintable(str string) bool {
 	for _, r := range str {
 		if !unicode.IsPrint(r) {
@@ -369,3 +369,29 @@ func IsGBK(data []byte) bool {
 
 	return true
 }
+
+// IsNumberStr check if the value is Number(integer, float) or not.
+// Play: todo
+func IsNumber(v any) bool {
+	return IsInt(v) || IsFloat(v)
+}
+
+// IsFloat check if the value is float(float32, float34) or not.
+// Play: todo
+func IsFloat(v any) bool {
+	switch v.(type) {
+	case float32, float64:
+		return true
+	}
+	return false
+}
+
+// IsInt check if the value is integer(int, unit) or not.
+// Play: todo
+func IsInt(v any) bool {
+	switch v.(type) {
+	case int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, uintptr:
+		return true
+	}
+	return false
+}

validator/validator_example_test.go

@@ -449,3 +449,57 @@ func ExampleIsPrintable() {
 	// true
 	// false
 }
+
+func ExampleIsInt() {
+	result1 := IsInt("")
+	result2 := IsInt("3")
+	result3 := IsInt(0.1)
+	result4 := IsInt(0)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// false
+	// true
+}
+
+func ExampleIsFloat() {
+	result1 := IsFloat("")
+	result2 := IsFloat("3")
+	result3 := IsFloat(0)
+	result4 := IsFloat(0.1)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// false
+	// true
+}
+
+func ExampleIsNumber() {
+	result1 := IsNumber("")
+	result2 := IsNumber("3")
+	result3 := IsNumber(0)
+	result4 := IsNumber(0.1)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// true
+	// true
+}

validator/validator_test.go

@@ -100,6 +100,34 @@ func TestIsJSON(t *testing.T) {
 	assert.Equal(false, IsJSON("&@#$%^&*"))
 }
 
+func TestIsNumber(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsNumber")
+
+	assert.Equal(false, IsNumber(""))
+	assert.Equal(false, IsNumber("3"))
+	assert.Equal(true, IsNumber(0))
+	assert.Equal(true, IsNumber(0.1))
+}
+
+func TestIsFloat(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsFloat")
+
+	assert.Equal(false, IsFloat(""))
+	assert.Equal(false, IsFloat("3"))
+	assert.Equal(false, IsFloat(0))
+	assert.Equal(true, IsFloat(0.1))
+}
+
+func TestIsInt(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsInt")
+
+	assert.Equal(false, IsInt(""))
+	assert.Equal(false, IsInt("3"))
+	assert.Equal(false, IsInt(0.1))
+	assert.Equal(true, IsInt(0))
+	assert.Equal(true, IsInt(-1))
+}
+
 func TestIsNumberStr(t *testing.T) {
 	assert := internal.NewAssert(t, "TestIsNumberStr")