doc: add play ground demo

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
 

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

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) {