release v2.1.16

doc: add new function docs
feat: add ContainBy function
2026-02-14 01:32:27 +08:00 · 2023-03-01 10:08:53 +08:00 · 2023-02-28 15:03:02 +08:00 · 2023-02-24 14:19:10 +08:00 · 2023-02-24 11:23:02 +08:00 · 2023-02-24 11:14:59 +08:00
38 changed files with 6242 additions and 191 deletions
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 <br/>

 ![Go version](https://img.shields.io/badge/go-%3E%3Dv1.18-9cf)
-[![Release](https://img.shields.io/badge/release-2.1.14-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-2.1.16-green.svg)](https://github.com/duke-git/lancet/releases)
 [![GoDoc](https://godoc.org/github.com/duke-git/lancet/v2?status.svg)](https://pkg.go.dev/github.com/duke-git/lancet/v2)
 [![Go Report Card](https://goreportcard.com/badge/github.com/duke-git/lancet/v2)](https://goreportcard.com/report/github.com/duke-git/lancet/v2)
 [![test](https://github.com/duke-git/lancet/actions/workflows/codecov.yml/badge.svg?branch=main&event=push)](https://github.com/duke-git/lancet/actions/workflows/codecov.yml)
@@ -24,7 +24,7 @@ English | [简体中文](./README_zh-CN.md)
 ## Feature

 -   👏 Comprehensive, efficient and reusable.
-   💪 300+ go util functions, support string, slice, datetime, net, crypt...
+-   💪 400+ go util functions, support string, slice, datetime, net, crypt...
 -   💅 Only depend on the go standard library.
 -   🌍 Unit test for every exported function.

@@ -38,10 +38,10 @@ English | [简体中文](./README_zh-CN.md)
 go get github.com/duke-git/lancet/v2 // will install latest version of v2.x.x
 ```

-2. <b>For users who use version below go1.18, you should install v1.x.x. The latest of v1.x.x is v1.3.5. </b>
+2. <b>For users who use version below go1.18, you should install v1.x.x. The latest of v1.x.x is v1.3.7. </b>

 ```go
-go get github.com/duke-git/lancet@v1.3.5 // below go1.18, install latest version of v1.x.x
+go get github.com/duke-git/lancet@v1.3.7 // below go1.18, install latest version of v1.x.x
 ```

 ## Usage
@@ -246,6 +246,12 @@ import "github.com/duke-git/lancet/v2/convertor"
 -   **<big>DecodeByte</big>** : decode byte slice data to target object.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor.md#DecodeByte)]
    [[play](https://go.dev/play/p/zI6xsmuQRbn)]
+-   **<big>DeepClone</big>** : creates a deep copy of passed item, can't clone unexported field of struct.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor.md#DeepClone)]
+    [[play](https://go.dev/play/p/j4DP5dquxnk)]
+-   **<big>CopyProperties</big>** : copies each field from the source struct into the destination struct.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor.md#CopyProperties)]
+

 ### 5. Cryptor package is for data encryption and decryption.

@@ -602,12 +608,24 @@ import "github.com/duke-git/lancet/v2/maputil"
 -   **<big>Filter</big>** : iterates over map, return a new map contains all key and value pairs pass the predicate function.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Filter)]
    [[play](https://go.dev/play/p/fSvF3wxuNG7)]
+-   **<big>FilterByKeys</big>** : iterates over map, return a new map whose keys are all given keys
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#FilterByKeys)]
+-   **<big>FilterByValues</big>** : iterates over map, return a new map whose values are all given values.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#FilterByValues)]
+-   **<big>OmitBy</big>** : the opposite of Filter, removes all the map elements for which the predicate function returns true.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#OmitBy)]
+-   **<big>OmitByKeys</big>** : the opposite of FilterByKeys, extracts all the map elements which keys are not omitted.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#OmitByKeys)]
+-   **<big>OmitByValues</big>** : the opposite of FilterByValues. remov all elements whose value are in the give slice.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#OmitByValues)]
 -   **<big>Intersect</big>** : iterates over maps, return a new map of key and value pairs in all given maps.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Intersect)]
    [[play](https://go.dev/play/p/Zld0oj3sjcC)]
 -   **<big>Keys</big>** : returns a slice of the map's keys.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Keys)]
    [[play](https://go.dev/play/p/xNB5bTb97Wd)]
+-   **<big>KeysBy</big>** : creates a slice whose element is the result of function mapper invoked by every map's key.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#KeysBy)]
 -   **<big>Merge</big>** : merge maps, next key will overwrite previous key.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Merge)]
    [[play](https://go.dev/play/p/H95LENF1uB-)]
@@ -617,6 +635,18 @@ import "github.com/duke-git/lancet/v2/maputil"
 -   **<big>Values</big>** : returns a slice of the map's values.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Values)]
    [[play](https://go.dev/play/p/CBKdUc5FTW6)]
+-   **<big>ValuesBy</big>** : creates a slice whose element is the result of function mapper invoked by every map's value.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#ValuesBy)]
+-   **<big>MapKeys</big>** : transforms a map to other type map by manipulating it's keys.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#MapKeys)]
+-   **<big>MapValues</big>** : transforms a map to other type map by manipulating it's values.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#MapValues)]
+-   **<big>Entries</big>** : transforms a map into array of key/value pairs.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Entries)]
+-   **<big>FromEntries</big>** : creates a map based on a slice of key/value pairs.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#FromEntries)]
+-   **<big>Transform</big>** : transform a map to another type map.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#Transform)]
 -   **<big>IsDisjoint</big>** : check two map are disjoint if they have no keys in common.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil.md#IsDisjoint)]
    [[play](https://go.dev/play/p/N9qgYg_Ho6f)]
@@ -802,6 +832,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Contain</big>** : check if the value is in the slice or not.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Contain)]
    [[play](https://go.dev/play/p/_454yEHcNjf)]
+-   **<big>ContainBy</big>** : returns true if predicate function return true.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#ContainBy)]
 -   **<big>ContainSubSlice</big>** : check if the slice contain a given subslice or not.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#ContainSubSlice)]
    [[play](https://go.dev/play/p/bcuQ3UT6Sev)]
@@ -832,9 +864,18 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>DeleteAt</big>** : delete the element of slice from specific start index to end index - 1.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#DeleteAt)]
    [[play](https://go.dev/play/p/pJ-d6MUWcvK)]
-   **<big>Drop</big>** : creates a slice with `n` elements dropped from the beginning when n > 0, or `n` elements dropped from the ending when n < 0.
+-   **<big>Drop</big>** : drop n elements from the start of a slice.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Drop)]
-    [[play](https://go.dev/play/p/pJ-d6MUWcvK)]
+    [[play](https://go.dev/play/p/jnPO2yQsT8H)]
+-   **<big>DropRight</big>** : drop n elements from the end of a slice.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#DropRight)]
+    [[play](https://go.dev/play/p/8bcXvywZezG)]
+-   **<big>DropWhile</big>** : drop n elements from the start of a slice while predicate function returns true.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#DropWhile)]
+    [[play](https://go.dev/play/p/4rt252UV_qs)]
+-   **<big>DropRightWhile</big>** : drop n elements from the end of a slice while predicate function returns true.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#DropRightWhile)]
+    [[play](https://go.dev/play/p/6wyK3zMY56e)]
 -   **<big>Equal</big>** : checks if two slices are equal: the same length and all elements' order and value are equal.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Equal)]
    [[play](https://go.dev/play/p/WcRQJ37ifPa)]
@@ -847,6 +888,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Filter</big>** : iterates over elements of slice, returning an slice of all elements pass the predicate function.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Filter)]
    [[play](https://go.dev/play/p/SdPna-7qK4T)]
+-   **<big>FilterMap</big>** : returns a slice which apply both filtering and mapping to the given slice.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#FilterMap)]
 -   **<big>Find</big>** : iterates over elements of slice, returning the first one that passes a truth test on predicate function.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Find)]
    [[play](https://go.dev/play/p/CBKeBoHVLgq)]
@@ -859,6 +902,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>FlattenDeep</big>** : flattens slice recursive to one level.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#FlattenDeep)]
    [[play](https://go.dev/play/p/yjYNHPyCFaF)]
+-   **<big>FlatMap</big>** : manipulates a slice and transforms and flattens it to a slice of another type.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#FlatMap)]
 -   **<big>ForEach</big>** : iterates over elements of slice and invokes function for each element.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#ForEach)]
    [[play](https://go.dev/play/p/DrPaa4YsHRF)]
@@ -910,6 +955,18 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Shuffle</big>** : shuffle the slice.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Shuffle)]
    [[play](https://go.dev/play/p/YHvhnWGU3Ge)]
+-   **<big>IsAscending</big>** : Checks if a slice is ascending order.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#IsAscending)]
+    [[play](https://go.dev/play/p/9CtsFjet4SH)]
+-   **<big>IsDescending</big>** : Checks if a slice is descending order.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#IsDescending)]
+    [[play](https://go.dev/play/p/U_LljFXma14)]
+-   **<big>IsSorted</big>** : Checks if a slice is sorted (ascending or descending).
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#IsSorted)]
+    [[play](https://go.dev/play/p/nCE8wPLwSA-)]
+-   **<big>IsSortedByKey</big>** : Checks if a slice is sorted by iteratee function.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#IsSortedByKey)]
+    [[play](https://go.dev/play/p/tUoGB7DOHI4)]
 -   **<big>Sort</big>** : sorts a slice of any ordered type(number or string).
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Sort)]
    [[play](https://go.dev/play/p/V9AVjzf_4Fk)]
@@ -996,6 +1053,8 @@ import "github.com/duke-git/lancet/v2/strutil"
 -   **<big>UpperFirst</big>** : converts the first character of string to upper case.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#UpperFirst)]
    [[play](https://go.dev/play/p/sBbBxRbs8MM)]
+-   **<big>Pad</big>** : pads string on the left and right side if it's shorter than size.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#Pad)]
 -   **<big>PadEnd</big>** : pads string with given characters on the right side if it's shorter than limit size. Padding characters are truncated if they exceed size.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#PadEnd)]
    [[play](https://go.dev/play/p/9xP8rN0vz--)]
@@ -1023,6 +1082,10 @@ import "github.com/duke-git/lancet/v2/strutil"
 -   **<big>Unwrap</big>** : unwrap a given string from anther string. will change source string.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#Unwrap)]
    [[play](https://go.dev/play/p/Ec2q4BzCpG-)]
+-   **<big>SplitWords</big>** : splits a string into words, word only contains alphabetic characters.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#SplitWords)]
+-   **<big>WordCount</big>** : return the number of meaningful word of a string, word only contains alphabetic characters.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil.md#WordCount)]

 ### 19. System package contain some functions about os, runtime, shell command.

@@ -1160,10 +1223,45 @@ import "github.com/duke-git/lancet/v2/xerror"
 ```

 #### Function list:
-
-   **<big>Unwrap</big>** : check if err is nil then it returns a valid value. If err is not nil, Unwrap panics with err.
+-   **<big>New</big>** : creates a new XError pointer instance with message.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#New)]
+    [[play](https://go.dev/play/p/w4oWZts7q7f)]
+-   **<big>Wrap</big>** : creates a new XError pointer instance based on error object, and add message.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#Wrap)]
+    [[play](https://go.dev/play/p/5385qT2dCi4)]
+-   **<big>Unwrap</big>** : returns unwrapped XError from err by errors.As. If no XError, returns nil.
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#Unwrap)]
-    [[play](https://go.dev/play/p/w84d7Mb3Afk)]
+    [[play](https://go.dev/play/p/LKMLep723tu)]
+-   **<big>XError_Wrap</big>** : creates a new XError and copy message and id to new one.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Wrap)]
+    [[play](https://go.dev/play/p/5385qT2dCi4)]
+-   **<big>XError_Unwrap</big>** : Compatible with github.com/pkg/errors.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Unwrap)]
+    [[play](https://go.dev/play/p/VUXJ8BST4c6)]
+-   **<big>XError_With</big>** : adds key and value related to the XError object.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_With)]
+    [[play](https://go.dev/play/p/ow8UISXX_Dp)]
+-   **<big>XError_Id</big>** : sets XError object id to check equality in XError.Is.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Id)]
+    [[play](https://go.dev/play/p/X6HBlsy58U9)]
+-   **<big>XError_Is</big>** : checks if target error is XError and Error.id of two errors are matched.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Is)]
+    [[play](https://go.dev/play/p/X6HBlsy58U9)]
+-   **<big>XError_Values</big>** : returns map of key and value that is set by XError.With function. 
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Values)]
+    [[play](https://go.dev/play/p/ow8UISXX_Dp)]
+-   **<big>XError_StackTrace</big>** : returns stack trace which is compatible with pkg/errors.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_StackTrace)]
+    [[play](https://go.dev/play/p/6FAvSQpa7pc)]
+-   **<big>XError_Info</big>** : returns information of xerror, which can be printed.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Info)]
+    [[play](https://go.dev/play/p/1ZX0ME1F-Jb)]
+-   **<big>XError_Error</big>** : implements standard error interface.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#XError_Error)]
+    [[play](https://go.dev/play/p/w4oWZts7q7f)]
+-   **<big>TryUnwrap</big>** : check if err is nil then it returns a valid value. If err is not nil, TryUnwrap panics with err.
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror.md#TryUnwrap)]
+    [[play](https://go.dev/play/p/acyZVkNZEeW)]


 ## How to Contribute
--- a/README_zh-CN.md
+++ b/README_zh-CN.md
@@ -4,7 +4,7 @@
 <br/>

 ![Go version](https://img.shields.io/badge/go-%3E%3Dv1.18-9cf)
-[![Release](https://img.shields.io/badge/release-2.1.14-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-2.1.16-green.svg)](https://github.com/duke-git/lancet/releases)
 [![GoDoc](https://godoc.org/github.com/duke-git/lancet/v2?status.svg)](https://pkg.go.dev/github.com/duke-git/lancet/v2)
 [![Go Report Card](https://goreportcard.com/badge/github.com/duke-git/lancet/v2)](https://goreportcard.com/report/github.com/duke-git/lancet/v2)
 [![test](https://github.com/duke-git/lancet/actions/workflows/codecov.yml/badge.svg?branch=main&event=push)](https://github.com/duke-git/lancet/actions/workflows/codecov.yml)
@@ -23,7 +23,7 @@
 ## 特性

 -   👏 全面、高效、可复用
-   💪 300+常用 go 工具函数，支持 string、slice、datetime、net、crypt...
+-   💪 400+常用 go 工具函数，支持 string、slice、datetime、net、crypt...
 -   💅 只依赖 go 标准库
 -   🌍 所有导出函数单元测试覆盖率 100%

@@ -37,10 +37,10 @@
 go get github.com/duke-git/lancet/v2 //安装v2最新版本v2.x.x
 ```

-2. <b>使用 go1.18 以下版本的用户，必须安装 v1.x.x。目前最新的 v1 版本是 v1.3.5。</b>
+2. <b>使用 go1.18 以下版本的用户，必须安装 v1.x.x。目前最新的 v1 版本是 v1.3.7。</b>

 ```go
-go get github.com/duke-git/lancet@v1.3.5 // 使用go1.18以下版本, 必须安装v1.x.x版本
+go get github.com/duke-git/lancet@v1.3.7 // 使用go1.18以下版本, 必须安装v1.x.x版本
 ```

 ## 用法
@@ -245,6 +245,12 @@ import "github.com/duke-git/lancet/v2/convertor"
 -   **<big>DecodeByte</big>** : 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。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor_zh-CN.md#DecodeByte)]
    [[play](https://go.dev/play/p/zI6xsmuQRbn)]
+-   **<big>DeepClone</big>** : 创建一个传入值的深拷贝, 无法克隆结构体的非导出字段。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor_zh-CN.md#DeepClone)]
+    [[play](https://go.dev/play/p/j4DP5dquxnk)]
+-   **<big>CopyProperties</big>** : 拷贝不同结构体之间的同名字段。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/convertor_zh-CN.md#CopyProperties)]
+

 ### 5. cryptor 加密包支持数据加密和解密，获取 md5，hash 值。支持 base64, md5, hmac, aes, des, rsa。

@@ -605,12 +611,24 @@ import "github.com/duke-git/lancet/v2/maputil"
 -   **<big>Filter</big>** : 迭代 map 中的每对 key 和 value，返回 map，其中的 key 和 value 符合 predicate 函数。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#Filter)]
    [[play](https://go.dev/play/p/fSvF3wxuNG7)]
+-   **<big>FilterByKeys</big>** : 迭代map, 返回一个新map，其key都是给定的key值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#FilterByKeys)]
+-   **<big>FilterByValues</big>** : 迭代map, 返回一个新map，其value都是给定的value值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#FilterByValues)]
+-   **<big>OmitBy</big>** : Filter的反向操作, 迭代map中的每对key和value, 删除符合predicate函数的key, value, 返回新map。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#OmitBy)]
+-   **<big>OmitByKeys</big>** : FilterByKeys的反向操作, 迭代map, 返回一个新map，其key不包括给定的key值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#OmitByKeys)]
+-   **<big>OmitByValues</big>** : FilterByValues的反向操作, 迭代map, 返回一个新map，其value不包括给定的value值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#OmitByValues)]
 -   **<big>Intersect</big>** : 多个 map 的交集操作。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#Intersect)]
    [[play](https://go.dev/play/p/Zld0oj3sjcC)]
 -   **<big>Keys</big>** : 返回 map 中所有 key 组成的切片。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#Keys)]
    [[play](https://go.dev/play/p/xNB5bTb97Wd)]
+-   **<big>KeysBy</big>** : 创建一个切片，其元素是每个map的key调用mapper函数的结果。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#KeysBy)]
 -   **<big>Merge</big>** : 合并多个 map, 相同的 key 会被之后的 key 覆盖。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#Merge)]
    [[play](https://go.dev/play/p/H95LENF1uB-)]
@@ -620,7 +638,19 @@ import "github.com/duke-git/lancet/v2/maputil"
 -   **<big>Values</big>** : 返回 map 中所有 values 组成的切片
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#Values)]
    [[play](https://go.dev/play/p/CBKdUc5FTW6)]
-   **<big>IsDisjoint</big>** : 验证两个 map 是否具有不同的 key。
+-   **<big>ValuesBy</big>** : 创建一个切片，其元素是每个map的value调用mapper函数的结果。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#ValuesBy)]
+-   **<big>MapKeys</big>** : 操作map的每个key，然后转为新的map。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#MapKeys)]
+-   **<big>MapValues</big>** : 操作map的每个value，然后转为新的map。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#MapValues)]
+-   **<big>Entries</big>** : 将map转换为键/值对切片。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#Entries)]
+-   **<big>FromEntries</big>** : 基于键/值对的切片创建map。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#FromEntries)]
+-   **<big>Transform</big>** : 将map转换为其他类型的map。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN#Transform)]
+-   **<big>IsDisjoint</big>** : 验证两个map是否具有不同的key。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/maputil_zh-CN.md#IsDisjoint)]
    [[play](https://go.dev/play/p/N9qgYg_Ho6f)]

@@ -809,6 +839,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Contain</big>** : 判断slice是否包含value。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Contain)]
    [[play](https://go.dev/play/p/_454yEHcNjf)]
+-   **<big>ContainBy</big>** : 根据predicate函数判断切片是否包含某个值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#ContainBy)]
 -   **<big>ContainSubSlice</big>** : 判断slice是否包含subslice。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#ContainSubSlice)]
    [[play](https://go.dev/play/p/bcuQ3UT6Sev)]
@@ -839,9 +871,18 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>DeleteAt</big>** : 删除切片中指定开始索引到结束索引的元素。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#DeleteAt)]
    [[play](https://go.dev/play/p/pJ-d6MUWcvK)]
-   **<big>Drop</big>** : 创建一个切片，当n > 0时从开头删除n个元素，或者当n < 0时从结尾删除n个元素。
+-   **<big>Drop</big>** : 从切片头部删除n个元素。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Drop)]
-    [[play](https://go.dev/play/p/pJ-d6MUWcvK)]
+    [[play](https://go.dev/play/p/jnPO2yQsT8H)]
+-   **<big>DropRight</big>** : 从切片尾部删除n个元素。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#DropRight)]
+    [[play](https://go.dev/play/p/8bcXvywZezG)]
+-   **<big>DropWhile</big>** : 从切片的头部删除n个元素，这个n个元素满足predicate函数返回true。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#DropWhile)]
+    [[play](https://go.dev/play/p/4rt252UV_qs)]
+-   **<big>DropRightWhile</big>** : 从切片的尾部删除n个元素，这个n个元素满足predicate函数返回true。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#DropRightWhile)]
+    [[play](https://go.dev/play/p/6wyK3zMY56e)]
 -   **<big>Equal</big>** : 检查两个切片是否相等，相等条件：切片长度相同，元素顺序和值都相同。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Equal)]
    [[play](https://go.dev/play/p/WcRQJ37ifPa)]
@@ -854,6 +895,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Filter</big>** : 返回切片中通过predicate函数真值测试的所有元素。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Filter)]
    [[play](https://go.dev/play/p/SdPna-7qK4T)]
+-   **<big>FilterMap</big>** : 返回一个将filter和map操作应用于给定切片的切片。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#FilterMap)]
 -   **<big>Find</big>** : 遍历切片的元素，返回第一个通过predicate函数真值测试的元素。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Find)]
    [[play](https://go.dev/play/p/CBKeBoHVLgq)]
@@ -866,6 +909,8 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>FlattenDeep</big>** : 将多维切片递归展平到一层。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#FlattenDeep)]
    [[play](https://go.dev/play/p/yjYNHPyCFaF)]
+-   **<big>FlatMap</big>** : 将切片转换为其它类型切片。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#FlatMap)]
 -   **<big>ForEach</big>** : 遍历切片的元素并为每个元素调用iteratee函数。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#ForEach)]
    [[play](https://go.dev/play/p/DrPaa4YsHRF)]
@@ -917,6 +962,18 @@ import "github.com/duke-git/lancet/v2/slice"
 -   **<big>Shuffle</big>** : 随机打乱切片中的元素顺序。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Shuffle)]
    [[play](https://go.dev/play/p/YHvhnWGU3Ge)]
+-   **<big>IsAscending</big>** : 检查切片元素是否按升序排列。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#IsAscending)]
+    [[play](https://go.dev/play/p/9CtsFjet4SH)]
+-   **<big>IsDescending</big>** : 检查切片元素是否按降序排列。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#IsDescending)]
+    [[play](https://go.dev/play/p/U_LljFXma14)]
+-   **<big>IsSorted</big>** : 检查切片元素是否是有序的（升序或降序）。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#IsSorted)]
+    [[play](https://go.dev/play/p/nCE8wPLwSA-)]
+-   **<big>IsSortedByKey</big>** : 通过iteratee函数，检查切片元素是否是有序的。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#IsSortedByKey)]
+    [[play](https://go.dev/play/p/tUoGB7DOHI4)]
 -   **<big>Sort</big>** : 对任何有序类型（数字或字符串）的切片进行排序，使用快速排序算法。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Sort)]
    [[play](https://go.dev/play/p/V9AVjzf_4Fk)]
@@ -1005,6 +1062,8 @@ import "github.com/duke-git/lancet/v2/strutil"
 -   **<big>UpperFirst</big>** : 将字符串的第一个字符转换为大写形式。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#UpperFirst)]
    [[play](https://go.dev/play/p/sBbBxRbs8MM)]
+-   **<big>Pad</big>** : 如果字符串长度短于size，则在左右两侧填充字符串。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#Pad)]
 -   **<big>PadEnd</big>** : 如果字符串短于限制大小，则在右侧用给定字符填充字符串。 如果填充字符超出大小，它们将被截断。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#PadEnd)]
    [[play](https://go.dev/play/p/9xP8rN0vz--)]
@@ -1032,6 +1091,10 @@ import "github.com/duke-git/lancet/v2/strutil"
 -   **<big>Unwrap</big>** : 从另一个字符串中解开一个给定的字符串。 将更改源字符串。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#Unwrap)]
    [[play](https://go.dev/play/p/Ec2q4BzCpG-)]
+-   **<big>SplitWords</big>** : 将字符串拆分为单词，只支持字母字符单词。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#SplitWords)]
+-   **<big>WordCount</big>** : 返回有意义单词的数量，只支持字母字符单词。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/strutil_zh-CN.md#WordCount)]

 ### 18. system 包含 os, runtime, shell command 的相关函数。

@@ -1171,11 +1234,46 @@ import "github.com/duke-git/lancet/v2/xerror"

 #### 函数列表:

-
-   **<big>Unwrap</big>** : 检查error, 如果err为nil则展开，则它返回一个有效值，如果err不是nil则Unwrap使用err发生panic。
+-   **<big>New</big>** : 创建XError对象实例。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#New)]
+    [[play](https://go.dev/play/p/w4oWZts7q7f)]
+-   **<big>Wrap</big>** : 根据error对象创建XError对象实例，可添加message。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#Wrap)]
+    [[play](https://go.dev/play/p/5385qT2dCi4)]
+-   **<big>Unwrap</big>** : 从error对象中解构出XError。
    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#Unwrap)]
-    [[play](https://go.dev/play/p/w84d7Mb3Afk)]
-
+    [[play](https://go.dev/play/p/LKMLep723tu)]
+-   **<big>XError_Wrap</big>** : 创建新的XError对象并将消息和id复制到新的对象中。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Wrap)]
+    [[play](https://go.dev/play/p/5385qT2dCi4)]
+-   **<big>XError_Unwrap</big>** : 解构XEerror为error对象。适配github.com/pkg/errors。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Unwrap)]
+    [[play](https://go.dev/play/p/VUXJ8BST4c6)]
+-   **<big>XError_With</big>** : 添加与XError对象的键和值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_With)]
+    [[play](https://go.dev/play/p/ow8UISXX_Dp)]
+-   **<big>XError_Id</big>** : 设置XError对象的id。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Id)]
+    [[play](https://go.dev/play/p/X6HBlsy58U9)]
+-   **<big>XError_Is</big>** : 检查目标error是否为XError，两个错误中的error.id是否匹配。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Is)]
+    [[play](https://go.dev/play/p/X6HBlsy58U9)]
+-   **<big>XError_Values</big>** : 返回由With设置的键和值的映射。将合并所有XError键和值。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Values)]
+    [[play](https://go.dev/play/p/ow8UISXX_Dp)]
+-   **<big>XError_StackTrace</big>** : 返回与pkg/error兼容的堆栈信息。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_StackTrace)]
+    [[play](https://go.dev/play/p/6FAvSQpa7pc)]
+-   **<big>XError_Info</big>** : 返回可打印的XError对象信息。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Info)]
+    [[play](https://go.dev/play/p/1ZX0ME1F-Jb)]
+-   **<big>XError_Error</big>** : 实现标准库的error接口。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#XError_Error)]
+    [[play](https://go.dev/play/p/w4oWZts7q7f)]
+-   **<big>TryUnwrap</big>** : 检查error, 如果err为nil则展开，则它返回一个有效值，如果err不是nil则Unwrap使用err发生panic。
+    [[doc](https://github.com/duke-git/lancet/blob/main/docs/xerror_zh-CN.md#TryUnwrap)]
+    [[play](https://go.dev/play/p/acyZVkNZEeW)]
+    

 ## 如何贡献代码

--- a/convertor/convertor.go
+++ b/convertor/convertor.go
@@ -9,6 +9,7 @@ import (
 	"encoding/binary"
 	"encoding/gob"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math"
 	"reflect"
@@ -324,3 +325,62 @@ func DecodeByte(data []byte, target any) error {
 	decoder := gob.NewDecoder(buffer)
 	return decoder.Decode(target)
 }
+
+// DeepClone creates a deep copy of passed item.
+// can't clone unexported field of struct
+// Play: https://go.dev/play/p/j4DP5dquxnk
+func DeepClone[T any](src T) T {
+	c := cloner{
+		ptrs: map[reflect.Type]map[uintptr]reflect.Value{},
+	}
+	result := c.clone(reflect.ValueOf(src))
+	if result.Kind() == reflect.Invalid {
+		var zeroValue T
+		return zeroValue
+	}
+
+	return result.Interface().(T)
+}
+
+// CopyProperties copies each field from the source into the destination. It recursively copies struct pointers and interfaces that contain struct pointers.
+// Play: todo
+func CopyProperties[T, U any](dst T, src U) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			err = errors.New(fmt.Sprintf("%v", e))
+		}
+	}()
+
+	dstType, dstValue := reflect.TypeOf(dst), reflect.ValueOf(dst)
+	srcType, srcValue := reflect.TypeOf(src), reflect.ValueOf(src)
+
+	if dstType.Kind() != reflect.Ptr || dstType.Elem().Kind() != reflect.Struct {
+		return errors.New("CopyProperties: param dst should be struct pointer")
+	}
+
+	if srcType.Kind() == reflect.Ptr {
+		srcType, srcValue = srcType.Elem(), srcValue.Elem()
+	}
+	if srcType.Kind() != reflect.Struct {
+		return errors.New("CopyProperties: param src should be a struct or struct pointer")
+	}
+
+	dstType, dstValue = dstType.Elem(), dstValue.Elem()
+
+	propertyNums := dstType.NumField()
+
+	for i := 0; i < propertyNums; i++ {
+		property := dstType.Field(i)
+		propertyValue := srcValue.FieldByName(property.Name)
+
+		if !propertyValue.IsValid() || property.Type != propertyValue.Type() {
+			continue
+		}
+
+		if dstValue.Field(i).CanSet() {
+			dstValue.Field(i).Set(propertyValue)
+		}
+	}
+
+	return nil
+}
--- a/convertor/convertor_example_test.go
+++ b/convertor/convertor_example_test.go
@@ -252,3 +252,88 @@ func ExampleDecodeByte() {
 	// Output:
 	// abc
 }
+
+func ExampleDeepClone() {
+	type Struct struct {
+		Str        string
+		Int        int
+		Float      float64
+		Bool       bool
+		Nil        interface{}
+		unexported string
+	}
+
+	cases := []interface{}{
+		true,
+		1,
+		0.1,
+		map[string]int{
+			"a": 1,
+			"b": 2,
+		},
+		&Struct{
+			Str:   "test",
+			Int:   1,
+			Float: 0.1,
+			Bool:  true,
+			Nil:   nil,
+			// unexported: "can't be cloned",
+		},
+	}
+
+	for _, item := range cases {
+		cloned := DeepClone(item)
+
+		isPointerEqual := &cloned == &item
+		fmt.Println(cloned, isPointerEqual)
+	}
+
+	// Output:
+	// true false
+	// 1 false
+	// 0.1 false
+	// map[a:1 b:2] false
+	// &{test 1 0.1 true <nil> } false
+}
+
+func ExampleCopyProperties() {
+	type Address struct {
+		Country string
+		ZipCode string
+	}
+
+	type User struct {
+		Name   string
+		Age    int
+		Role   string
+		Addr   Address
+		Hobbys []string
+		salary int
+	}
+
+	type Employee struct {
+		Name   string
+		Age    int
+		Role   string
+		Addr   Address
+		Hobbys []string
+		salary int
+	}
+
+	user := User{Name: "user001", Age: 10, Role: "Admin", Addr: Address{Country: "CN", ZipCode: "001"}, Hobbys: []string{"a", "b"}, salary: 1000}
+
+	employee1 := Employee{}
+	CopyProperties(&employee1, &user)
+
+	employee2 := Employee{Name: "employee001", Age: 20, Role: "User",
+		Addr: Address{Country: "UK", ZipCode: "002"}, salary: 500}
+
+	CopyProperties(&employee2, &user)
+
+	fmt.Println(employee1)
+	fmt.Println(employee2)
+
+	// Output:
+	// {user001 10 Admin {CN 001} [a b] 0}
+	// {user001 10 Admin {CN 001} [a b] 500}
+}
--- a/convertor/convertor_internal.go
+++ b/convertor/convertor_internal.go
@@ -0,0 +1,216 @@
+// Copyright 2023 dudaodong@gmail.com. All rights reserved.
+// Use of this source code is governed by MIT license
+
+// Package convertor implements some functions to convert data.
+package convertor
+
+import "reflect"
+
+type cloner struct {
+	ptrs map[reflect.Type]map[uintptr]reflect.Value
+}
+
+// clone return a duplicate of passed item.
+func (c *cloner) clone(v reflect.Value) reflect.Value {
+	switch v.Kind() {
+	case reflect.Invalid:
+		return reflect.ValueOf(nil)
+
+	// bool
+	case reflect.Bool:
+		return reflect.ValueOf(v.Bool())
+
+	//int
+	case reflect.Int:
+		return reflect.ValueOf(int(v.Int()))
+	case reflect.Int8:
+		return reflect.ValueOf(int8(v.Int()))
+	case reflect.Int16:
+		return reflect.ValueOf(int16(v.Int()))
+	case reflect.Int32:
+		return reflect.ValueOf(int32(v.Int()))
+	case reflect.Int64:
+		return reflect.ValueOf(v.Int())
+
+	// uint
+	case reflect.Uint:
+		return reflect.ValueOf(uint(v.Uint()))
+	case reflect.Uint8:
+		return reflect.ValueOf(uint8(v.Uint()))
+	case reflect.Uint16:
+		return reflect.ValueOf(uint16(v.Uint()))
+	case reflect.Uint32:
+		return reflect.ValueOf(uint32(v.Uint()))
+	case reflect.Uint64:
+		return reflect.ValueOf(v.Uint())
+
+	// float
+	case reflect.Float32:
+		return reflect.ValueOf(float32(v.Float()))
+	case reflect.Float64:
+		return reflect.ValueOf(v.Float())
+
+	// complex
+	case reflect.Complex64:
+		return reflect.ValueOf(complex64(v.Complex()))
+	case reflect.Complex128:
+		return reflect.ValueOf(v.Complex())
+
+	// string
+	case reflect.String:
+		return reflect.ValueOf(v.String())
+
+	// array
+	case reflect.Array, reflect.Slice:
+		return c.cloneArray(v)
+
+	// map
+	case reflect.Map:
+		return c.cloneMap(v)
+
+	// Ptr
+	case reflect.Ptr:
+		return c.clonePtr(v)
+
+	// struct
+	case reflect.Struct:
+		return c.cloneStruct(v)
+
+	// func
+	case reflect.Func:
+		return v
+
+	// interface
+	case reflect.Interface:
+		return c.clone(v.Elem())
+
+	}
+
+	return reflect.Zero(v.Type())
+}
+
+func (c *cloner) cloneArray(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	arr := reflect.MakeSlice(v.Type(), v.Len(), v.Len())
+
+	for i := 0; i < v.Len(); i++ {
+		val := c.clone(v.Index(i))
+
+		if val.IsValid() {
+			continue
+		}
+
+		item := arr.Index(i)
+		if !item.CanSet() {
+			continue
+		}
+
+		item.Set(val.Convert(item.Type()))
+	}
+
+	return arr
+}
+
+func (c *cloner) cloneMap(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	clonedMap := reflect.MakeMap(v.Type())
+
+	for _, key := range v.MapKeys() {
+		value := v.MapIndex(key)
+		clonedKey := c.clone(key)
+		clonedValue := c.clone(value)
+
+		if !isNillable(clonedKey) || !clonedKey.IsNil() {
+			clonedKey = clonedKey.Convert(key.Type())
+		}
+
+		if (!isNillable(clonedValue) || !clonedValue.IsNil()) && clonedValue.IsValid() {
+			clonedValue = clonedValue.Convert(value.Type())
+		}
+
+		if !clonedValue.IsValid() {
+			clonedValue = reflect.Zero(clonedMap.Type().Elem())
+		}
+
+		clonedMap.SetMapIndex(clonedKey, clonedValue)
+	}
+
+	return clonedMap
+}
+
+func isNillable(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Chan, reflect.Interface, reflect.Ptr, reflect.Func:
+		return true
+	}
+	return false
+}
+
+func (c *cloner) clonePtr(v reflect.Value) reflect.Value {
+	if v.IsNil() {
+		return reflect.Zero(v.Type())
+	}
+
+	var newVal reflect.Value
+
+	if v.Elem().CanAddr() {
+		ptrs, exists := c.ptrs[v.Type()]
+		if exists {
+			if newVal, exists := ptrs[v.Elem().UnsafeAddr()]; exists {
+				return newVal
+			}
+		}
+	}
+
+	newVal = c.clone(v.Elem())
+
+	if v.Elem().CanAddr() {
+		ptrs, exists := c.ptrs[v.Type()]
+		if exists {
+			if newVal, exists := ptrs[v.Elem().UnsafeAddr()]; exists {
+				return newVal
+			}
+		}
+	}
+
+	clonedPtr := reflect.New(newVal.Type())
+	clonedPtr.Elem().Set(newVal)
+
+	return clonedPtr
+}
+
+func (c *cloner) cloneStruct(v reflect.Value) reflect.Value {
+	clonedStructPtr := reflect.New(v.Type())
+	clonedStruct := clonedStructPtr.Elem()
+
+	if v.CanAddr() {
+		ptrs := c.ptrs[clonedStructPtr.Type()]
+		if ptrs == nil {
+			ptrs = make(map[uintptr]reflect.Value)
+			c.ptrs[clonedStructPtr.Type()] = ptrs
+		}
+		ptrs[v.UnsafeAddr()] = clonedStructPtr
+	}
+
+	for i := 0; i < v.NumField(); i++ {
+		newStructValue := clonedStruct.Field(i)
+		if !newStructValue.CanSet() {
+			continue
+		}
+
+		clonedVal := c.clone(v.Field(i))
+		if !clonedVal.IsValid() {
+			continue
+		}
+
+		newStructValue.Set(clonedVal.Convert(newStructValue.Type()))
+	}
+
+	return clonedStruct
+}
--- a/convertor/convertor_test.go
+++ b/convertor/convertor_test.go
@@ -2,6 +2,7 @@ package convertor

 import (
 	"fmt"
+	"reflect"
 	"strconv"
 	"testing"

@@ -253,3 +254,97 @@ func TestDecodeByte(t *testing.T) {
 	assert.IsNil(err)
 	assert.Equal("abc", obj)
 }
+
+func TestDeepClone(t *testing.T) {
+	// assert := internal.NewAssert(t, "TestDeepClone")
+
+	type Struct struct {
+		Str        string
+		Int        int
+		Float      float64
+		Bool       bool
+		Nil        interface{}
+		unexported string
+	}
+
+	cases := []interface{}{
+		true,
+		1,
+		0.1,
+		map[string]int{
+			"a": 1,
+			"b": 2,
+		},
+		&Struct{
+			Str:   "test",
+			Int:   1,
+			Float: 0.1,
+			Bool:  true,
+			Nil:   nil,
+			// unexported: "can't be cloned",
+		},
+	}
+
+	for i, item := range cases {
+		cloned := DeepClone(item)
+
+		t.Log(cloned)
+		if &cloned == &item {
+			t.Fatalf("[TestDeepClone case #%d failed]: equal pointer", i)
+		}
+
+		if !reflect.DeepEqual(item, cloned) {
+			t.Fatalf("[TestDeepClone case #%d failed] unequal objects", i)
+		}
+	}
+}
+
+func TestCopyProperties(t *testing.T) {
+	assert := internal.NewAssert(t, "TestCopyProperties")
+
+	type Address struct {
+		Country string
+		ZipCode string
+	}
+
+	type User struct {
+		Name   string
+		Age    int
+		Role   string
+		Addr   Address
+		Hobbys []string
+		salary int
+	}
+
+	type Employee struct {
+		Name   string
+		Age    int
+		Role   string
+		Addr   Address
+		Hobbys []string
+		salary int
+	}
+
+	user := User{Name: "user001", Age: 10, Role: "Admin", Addr: Address{Country: "CN", ZipCode: "001"}, Hobbys: []string{"a", "b"}, salary: 1000}
+
+	employee1 := Employee{}
+
+	err := CopyProperties(&employee1, &user)
+
+	assert.IsNil(err)
+	assert.Equal("user001", employee1.Name)
+	assert.Equal("Admin", employee1.Role)
+	assert.Equal("CN", employee1.Addr.Country)
+	assert.Equal(0, employee1.salary)
+
+	employee2 := Employee{Name: "employee001", Age: 20, Role: "User",
+		Addr: Address{Country: "UK", ZipCode: "002"}, salary: 500}
+
+	err = CopyProperties(&employee2, &user)
+
+	assert.IsNil(err)
+	assert.Equal("user001", employee2.Name)
+	assert.Equal("Admin", employee2.Role)
+	assert.Equal("CN", employee2.Addr.Country)
+	assert.Equal(500, employee2.salary)
+}
--- a/cryptor/crypto_internal.go
+++ b/cryptor/crypto_internal.go
@@ -2,11 +2,11 @@ package cryptor

 import "bytes"

-func generateAesKey(key []byte) []byte {
-	genKey := make([]byte, 16)
+func generateAesKey(key []byte, size int) []byte {
+	genKey := make([]byte, size)
 	copy(genKey, key)
-	for i := 16; i < len(key); {
-		for j := 0; j < 16 && i < len(key); j, i = j+1, i+1 {
+	for i := size; i < len(key); {
+		for j := 0; j < size && i < len(key); j, i = j+1, i+1 {
 			genKey[j] ^= key[i]
 		}
 	}
--- a/cryptor/encrypt.go
+++ b/cryptor/encrypt.go
@@ -23,6 +23,11 @@ import (
 // len(key) should be 16, 24 or 32.
 // Play: https://go.dev/play/p/jT5irszHx-j
 func AesEcbEncrypt(data, key []byte) []byte {
+	size := len(key)
+	if size != 16 && size != 24 && size != 32 {
+		panic("key length shoud be 16 or 24 or 32")
+	}
+
 	length := (len(data) + aes.BlockSize) / aes.BlockSize
 	plain := make([]byte, length*aes.BlockSize)

@@ -34,7 +39,7 @@ func AesEcbEncrypt(data, key []byte) []byte {
 	}

 	encrypted := make([]byte, len(plain))
-	cipher, _ := aes.NewCipher(generateAesKey(key))
+	cipher, _ := aes.NewCipher(generateAesKey(key, size))

 	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])
@@ -47,7 +52,11 @@ func AesEcbEncrypt(data, key []byte) []byte {
 // len(key) should be 16, 24 or 32.
 // Play: https://go.dev/play/p/jT5irszHx-j
 func AesEcbDecrypt(encrypted, key []byte) []byte {
-	cipher, _ := aes.NewCipher(generateAesKey(key))
+	size := len(key)
+	if size != 16 && size != 24 && size != 32 {
+		panic("key length shoud be 16 or 24 or 32")
+	}
+	cipher, _ := aes.NewCipher(generateAesKey(key, size))
 	decrypted := make([]byte, len(encrypted))

 	for bs, be := 0, cipher.BlockSize(); bs < len(encrypted); bs, be = bs+cipher.BlockSize(), be+cipher.BlockSize() {
--- a/docs/convertor.md
+++ b/docs/convertor.md
@@ -1,15 +1,17 @@
 # Convertor
+
 Package convertor contains some functions for data type convertion.

 <div STYLE="page-break-after: always;"></div>

 ## Source:

- [https://github.com/duke-git/lancet/blob/main/convertor/convertor.go](https://github.com/duke-git/lancet/blob/main/convertor/convertor.go)
+-   [https://github.com/duke-git/lancet/blob/main/convertor/convertor.go](https://github.com/duke-git/lancet/blob/main/convertor/convertor.go)

 <div STYLE="page-break-after: always;"></div>

 ## Usage:
+
 ```go
 import (
    "github.com/duke-git/lancet/v2/convertor"
@@ -19,28 +21,32 @@ import (
 <div STYLE="page-break-after: always;"></div>

 ## Index
- [ColorHexToRGB](#ColorHexToRGB)
- [ColorRGBToHex](#ColorRGBToHex)
- [ToBool](#ToBool)
- [ToBytes](#ToBytes)
- [ToChar](#ToChar)
- [ToChannel](#ToChannel)
- [ToFloat](#ToFloat)
- [ToInt](#ToInt)
- [ToJson](#ToJson)
- [ToMap](#ToMap)
- [ToPointer](#ToPointer)
- [ToString](#ToString)
- [StructToMap](#StructToMap)
- [MapToSlice](#MapToSlice)
- [EncodeByte](#EncodeByte)
- [DecodeByte](#DecodeByte)
+
+-   [ColorHexToRGB](#ColorHexToRGB)
+-   [ColorRGBToHex](#ColorRGBToHex)
+-   [ToBool](#ToBool)
+-   [ToBytes](#ToBytes)
+-   [ToChar](#ToChar)
+-   [ToChannel](#ToChannel)
+-   [ToFloat](#ToFloat)
+-   [ToInt](#ToInt)
+-   [ToJson](#ToJson)
+-   [ToMap](#ToMap)
+-   [ToPointer](#ToPointer)
+-   [ToString](#ToString)
+-   [StructToMap](#StructToMap)
+-   [MapToSlice](#MapToSlice)
+-   [EncodeByte](#EncodeByte)
+-   [DecodeByte](#DecodeByte)
+-   [DeepClone](#DeepClone)
+-   [CopyProperties](#CopyProperties)

 <div STYLE="page-break-after: always;"></div>

 ## Documentation

 ### <span id="ColorHexToRGB">ColorHexToRGB</span>
+
 <p>Convert color hex to color rgb.</p>

 <b>Signature:</b>
@@ -48,6 +54,7 @@ import (
 ```go
 func ColorHexToRGB(colorHex string) (red, green, blue int)
 ```
+
 <b>Example:</b>

 ```go
@@ -78,6 +85,7 @@ func main() {
 ```go
 func ColorRGBToHex(red, green, blue int) string
 ```
+
 <b>Example:</b>

 ```go
@@ -110,6 +118,7 @@ func main() {
 ```go
 func ToBool(s string) (bool, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -150,6 +159,7 @@ func main() {
 ```go
 func ToBytes(data any) ([]byte, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -182,6 +192,7 @@ func main() {
 ```go
 func ToChar(s string) []string
 ```
+
 <b>Example:</b>

 ```go
@@ -217,6 +228,7 @@ func main() {
 ```go
 func ToChannel[T any](array []T) <-chan T
 ```
+
 <b>Example:</b>

 ```go
@@ -253,6 +265,7 @@ func main() {
 ```go
 func ToFloat(value any) (float64, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -297,6 +310,7 @@ func main() {
 ```go
 func ToInt(value any) (int64, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -338,6 +352,7 @@ func main() {
 ```go
 func ToJson(value any) (string, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -372,6 +387,7 @@ func main() {
 ```go
 func ToMap[T any, K comparable, V any](array []T, iteratee func(T) (K, V)) map[K]V
 ```
+
 <b>Example:</b>

 ```go
@@ -412,6 +428,7 @@ func main() {
 ```go
 func ToPointer[T any](value T) *T
 ```
+
 <b>Example:</b>

 ```go
@@ -424,8 +441,8 @@ import (

 func main() {
    result := convertor.ToPointer(123)
-    fmt.Println(*result) 
-    
+    fmt.Println(*result)
+
    // Output:
    // 123
 }
@@ -440,6 +457,7 @@ func main() {
 ```go
 func ToString(value any) string
 ```
+
 <b>Example:</b>

 ```go
@@ -487,6 +505,7 @@ func main() {
 ```go
 func StructToMap(value any) (map[string]any, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -524,6 +543,7 @@ func main() {
 ```go
 func MapToSlice[T any, K comparable, V any](aMap map[K]V, iteratee func(K, V) T) []T
 ```
+
 <b>Example:</b>

 ```go
@@ -544,7 +564,6 @@ func main() {
 }
 ```

-
 ### <span id="EncodeByte">EncodeByte</span>

 <p>Encode data to byte slice.</p>
@@ -554,6 +573,7 @@ func main() {
 ```go
 func EncodeByte(data any) ([]byte, error)
 ```
+
 <b>Example:</b>

 ```go
@@ -582,6 +602,7 @@ func main() {
 ```go
 func DecodeByte(data []byte, target any) error
 ```
+
 <b>Example:</b>

 ```go
@@ -595,15 +616,144 @@ import (
 func main() {
    var result string
    byteData := []byte{6, 12, 0, 3, 97, 98, 99}
-    
+
    err := convertor.DecodeByte(byteData, &result)
    if err != nil {
        return
    }

    fmt.Println(result)
-    
+
    // Output:
    // abc
 }
+```
+
+
+### <span id="DeepClone">DeepClone</span>
+
+<p>Creates a deep copy of passed item, can't clone unexported field of struct.</p>
+
+<b>Signature:</b>
+
+```go
+func DeepClone[T any](src T) T
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/convertor"
+)
+
+func main() {
+    type Struct struct {
+        Str        string
+        Int        int
+        Float      float64
+        Bool       bool
+        Nil        interface{}
+        unexported string
+    }
+
+    cases := []interface{}{
+        true,
+        1,
+        0.1,
+        map[string]int{
+            "a": 1,
+            "b": 2,
+        },
+        &Struct{
+            Str:   "test",
+            Int:   1,
+            Float: 0.1,
+            Bool:  true,
+            Nil:   nil,
+            // unexported: "can't be cloned",
+        },
+    }
+
+    for _, item := range cases {
+        cloned := convertor.DeepClone(item)
+
+        isPointerEqual := &cloned == &item
+        fmt.Println(cloned, isPointerEqual)
+    }
+
+    // Output:
+    // true false
+    // 1 false
+    // 0.1 false
+    // map[a:1 b:2] false
+    // &{test 1 0.1 true <nil> } false
+}
+```
+
+
+### <span id="CopyProperties">CopyProperties</span>
+
+<p>Copies each field from the source struct into the destination struct.</p>
+
+<b>Signature:</b>
+
+```go
+func CopyProperties[T, U any](dst T, src U) (err error)
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/convertor"
+)
+
+func main() {
+    type Address struct {
+        Country string
+        ZipCode string
+    }
+
+    type User struct {
+        Name   string
+        Age    int
+        Role   string
+        Addr   Address
+        Hobbys []string
+        salary int
+    }
+
+    type Employee struct {
+        Name   string
+        Age    int
+        Role   string
+        Addr   Address
+        Hobbys []string
+        salary int
+    }
+
+    user := User{Name: "user001", Age: 10, Role: "Admin", Addr: Address{Country: "CN", ZipCode: "001"}, Hobbys: []string{"a", "b"}, salary: 1000}
+
+    employee1 := Employee{}
+    CopyProperties(&employee1, &user)
+
+    employee2 := Employee{Name: "employee001", Age: 20, Role: "User",
+        Addr: Address{Country: "UK", ZipCode: "002"}, salary: 500}
+
+    CopyProperties(&employee2, &user)
+
+    fmt.Println(employee1)
+    fmt.Println(employee2)
+
+    // Output:
+    // {user001 10 Admin {CN 001} [a b] 0}
+    // {user001 10 Admin {CN 001} [a b] 500}
+}
 ```
--- a/docs/convertor_zh-CN.md
+++ b/docs/convertor_zh-CN.md
@@ -1,11 +1,12 @@
 # Convertor
-convertor转换器包支持一些常见的数据类型转换
+
+convertor 转换器包支持一些常见的数据类型转换

 <div STYLE="page-break-after: always;"></div>

 ## 源码:

- [https://github.com/duke-git/lancet/blob/main/convertor/convertor.go](https://github.com/duke-git/lancet/blob/main/convertor/convertor.go)
+-   [https://github.com/duke-git/lancet/blob/main/convertor/convertor.go](https://github.com/duke-git/lancet/blob/main/convertor/convertor.go)

 <div STYLE="page-break-after: always;"></div>

@@ -21,29 +22,32 @@ import (

 ## 目录

- [ColorHexToRGB](#ColorHexToRGB)
- [ColorRGBToHex](#ColorRGBToHex)
- [ToBool](#ToBool)
- [ToBytes](#ToBytes)
- [ToChar](#ToChar)
- [ToChannel](#ToChannel)
- [ToFloat](#ToFloat)
- [ToInt](#ToInt)
- [ToJson](#ToJson)
- [ToMap](#ToMap)
- [ToPointer](#ToPointer)
- [ToString](#ToString)
- [StructToMap](#StructToMap)
- [MapToSlice](#MapToSlice)
- [EncodeByte](#EncodeByte)
- [DecodeByte](#DecodeByte)
+-   [ColorHexToRGB](#ColorHexToRGB)
+-   [ColorRGBToHex](#ColorRGBToHex)
+-   [ToBool](#ToBool)
+-   [ToBytes](#ToBytes)
+-   [ToChar](#ToChar)
+-   [ToChannel](#ToChannel)
+-   [ToFloat](#ToFloat)
+-   [ToInt](#ToInt)
+-   [ToJson](#ToJson)
+-   [ToMap](#ToMap)
+-   [ToPointer](#ToPointer)
+-   [ToString](#ToString)
+-   [StructToMap](#StructToMap)
+-   [MapToSlice](#MapToSlice)
+-   [EncodeByte](#EncodeByte)
+-   [DecodeByte](#DecodeByte)
+-   [DeepClone](#DeepClone)
+-   [CopyProperties](#CopyProperties)
+

 <div STYLE="page-break-after: always;"></div>

 ## 文档

-
 ### <span id="ColorHexToRGB">ColorHexToRGB</span>
+
 <p>颜色值十六进制转rgb。</p>

 <b>函数签名:</b>
@@ -51,6 +55,7 @@ import (
 ```go
 func ColorHexToRGB(colorHex string) (red, green, blue int)
 ```
+
 <b>示例:</b>

 ```go
@@ -81,6 +86,7 @@ func main() {
 ```go
 func ColorRGBToHex(red, green, blue int) string
 ```
+
 <b>示例:</b>

 ```go
@@ -113,6 +119,7 @@ func main() {
 ```go
 func ToBool(s string) (bool, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -153,6 +160,7 @@ func main() {
 ```go
 func ToBytes(data any) ([]byte, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -185,6 +193,7 @@ func main() {
 ```go
 func ToChar(s string) []string
 ```
+
 <b>示例:</b>

 ```go
@@ -220,6 +229,7 @@ func main() {
 ```go
 func ToChannel[T any](array []T) <-chan T
 ```
+
 <b>示例:</b>

 ```go
@@ -256,6 +266,7 @@ func main() {
 ```go
 func ToFloat(value any) (float64, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -300,6 +311,7 @@ func main() {
 ```go
 func ToInt(value any) (int64, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -341,6 +353,7 @@ func main() {
 ```go
 func ToJson(value any) (string, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -375,6 +388,7 @@ func main() {
 ```go
 func ToMap[T any, K comparable, V any](array []T, iteratee func(T) (K, V)) map[K]V
 ```
+
 <b>示例:</b>

 ```go
@@ -415,6 +429,7 @@ func main() {
 ```go
 func ToPointer[T any](value T) *T
 ```
+
 <b>示例:</b>

 ```go
@@ -427,8 +442,8 @@ import (

 func main() {
    result := convertor.ToPointer(123)
-    fmt.Println(*result) 
-    
+    fmt.Println(*result)
+
    // Output:
    // 123
 }
@@ -443,6 +458,7 @@ func main() {
 ```go
 func ToString(value any) string
 ```
+
 <b>示例:</b>

 ```go
@@ -490,6 +506,7 @@ func main() {
 ```go
 func StructToMap(value any) (map[string]any, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -527,6 +544,7 @@ func main() {
 ```go
 func MapToSlice[T any, K comparable, V any](aMap map[K]V, iteratee func(K, V) T) []T
 ```
+
 <b>示例:</b>

 ```go
@@ -556,6 +574,7 @@ func main() {
 ```go
 func EncodeByte(data any) ([]byte, error)
 ```
+
 <b>示例:</b>

 ```go
@@ -584,6 +603,7 @@ func main() {
 ```go
 func DecodeByte(data []byte, target any) error
 ```
+
 <b>示例:</b>

 ```go
@@ -597,15 +617,142 @@ import (
 func main() {
    var result string
    byteData := []byte{6, 12, 0, 3, 97, 98, 99}
-    
+
    err := convertor.DecodeByte(byteData, &result)
    if err != nil {
        return
    }

    fmt.Println(result)
-    
+
    // Output:
    // abc
 }
+```
+
+### <span id="DeepClone">DeepClone</span>
+
+<p>创建一个传入值的深拷贝, 无法克隆结构体的非导出字段。</p>
+
+<b>函数签名:</b>
+
+```go
+func DeepClone[T any](src T) T
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/convertor"
+)
+
+func main() {
+    type Struct struct {
+        Str        string
+        Int        int
+        Float      float64
+        Bool       bool
+        Nil        interface{}
+        unexported string
+    }
+
+    cases := []interface{}{
+        true,
+        1,
+        0.1,
+        map[string]int{
+            "a": 1,
+            "b": 2,
+        },
+        &Struct{
+            Str:   "test",
+            Int:   1,
+            Float: 0.1,
+            Bool:  true,
+            Nil:   nil,
+            // unexported: "can't be cloned",
+        },
+    }
+
+    for _, item := range cases {
+        cloned := convertor.DeepClone(item)
+
+        isPointerEqual := &cloned == &item
+        fmt.Println(cloned, isPointerEqual)
+    }
+
+    // Output:
+    // true false
+    // 1 false
+    // 0.1 false
+    // map[a:1 b:2] false
+    // &{test 1 0.1 true <nil> } false
+}
+```
+
+### <span id="CopyProperties">CopyProperties</span>
+
+<p>拷贝不同结构体之间的同名字段。</p>
+
+<b>函数签名:</b>
+
+```go
+func CopyProperties[T, U any](dst T, src U) (err error)
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/convertor"
+)
+
+func main() {
+    type Address struct {
+        Country string
+        ZipCode string
+    }
+
+    type User struct {
+        Name   string
+        Age    int
+        Role   string
+        Addr   Address
+        Hobbys []string
+        salary int
+    }
+
+    type Employee struct {
+        Name   string
+        Age    int
+        Role   string
+        Addr   Address
+        Hobbys []string
+        salary int
+    }
+
+    user := User{Name: "user001", Age: 10, Role: "Admin", Addr: Address{Country: "CN", ZipCode: "001"}, Hobbys: []string{"a", "b"}, salary: 1000}
+
+    employee1 := Employee{}
+    CopyProperties(&employee1, &user)
+
+    employee2 := Employee{Name: "employee001", Age: 20, Role: "User",
+        Addr: Address{Country: "UK", ZipCode: "002"}, salary: 500}
+
+    CopyProperties(&employee2, &user)
+
+    fmt.Println(employee1)
+    fmt.Println(employee2)
+
+    // Output:
+    // {user001 10 Admin {CN 001} [a b] 0}
+    // {user001 10 Admin {CN 001} [a b] 500}
+}
 ```
--- a/docs/function.md
+++ b/docs/function.md
@@ -29,6 +29,7 @@ import (
 -   [Compose](#Compose)
 -   [Debounced](#Debounced)
 -   [Delay](#Delay)
+-   [Schedule](#Schedule)
 -   [Pipeline](#Pipeline)
 -   [Watcher](#Watcher)

--- a/docs/function_zh-CN.md
+++ b/docs/function_zh-CN.md
@@ -29,6 +29,7 @@ import (
 -   [Compose](#Compose)
 -   [Debounced](#Debounced)
 -   [Delay](#Delay)
+-   [Schedule](#Schedule)
 -   [Pipeline](#Pipeline)
 -   [Watcher](#Watcher)

@@ -206,7 +207,7 @@ import (

 func main() {
    count := 0
-    
+
    add := func() {
        count++
    }
--- a/docs/maputil.md
+++ b/docs/maputil.md
@@ -24,11 +24,23 @@ import (

 -   [ForEach](#ForEach)
 -   [Filter](#Filter)
+-   [FilterByKeys](#FilterByKeys)
+-   [FilterByValues](#FilterByValues)
+-   [OmitBy](#OmitBy)
+-   [OmitByKeys](#OmitByKeys)
+-   [OmitByValues](#OmitByValues)
 -   [Intersect](#Intersect)
 -   [Keys](#Keys)
+-   [Values](#Values)
+-   [KeysBy](#KeysBy)
+-   [ValuesBy](#ValuesBy)
+-   [MapKeys](#MapKeys)
+-   [MapValues](#MapValues)
+-   [Entries](#Entries)
+-   [FromEntries](#FromEntries)
+-   [Transform](#Transform)
 -   [Merge](#Merge)
 -   [Minus](#Minus)
-   [Values](#Values)
 -   [IsDisjoint](#IsDisjoint)

 <div STYLE="page-break-after: always;"></div>
@@ -121,6 +133,205 @@ func main() {
 }
 ```

+
+### <span id="FilterByKeys">FilterByKeys</span>
+
+<p>Iterates over map, return a new map whose keys are all given keys.</p>
+
+<b>Signature:</b>
+
+```go
+func FilterByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.FilterByKeys(m, []string{"a", "b"})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2]
+}
+```
+
+
+### <span id="FilterByValues">FilterByValues</span>
+
+<p>Iterates over map, return a new map whose values are all given values.</p>
+
+<b>Signature:</b>
+
+```go
+func FilterByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.FilterByValues(m, []int{3, 4})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[c:3 d:4]
+}
+```
+
+
+### <span id="OmitBy">OmitBy</span>
+
+<p>OmitBy is the opposite of Filter, removes all the map elements for which the predicate function returns true.</p>
+
+<b>Signature:</b>
+
+```go
+func OmitBy[K comparable, V any](m map[K]V, predicate func(key K, value V) bool) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+    isEven := func(_ string, value int) bool {
+        return value%2 == 0
+    }
+
+    result := maputil.OmitBy(m, isEven)
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 c:3 e:5]
+}
+```
+
+
+### <span id="OmitByKeys">OmitByKeys</span>
+
+<p>The opposite of FilterByKeys, extracts all the map elements which keys are not omitted.</p>
+
+<b>Signature:</b>
+
+```go
+func OmitByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.OmitByKeys(m, []string{"a", "b"})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[c:3 d:4 e:5]
+}
+```
+
+
+### <span id="OmitByValues">OmitByValues</span>
+
+<p>The opposite of FilterByValues. remov all elements whose value are in the give slice.</p>
+
+<b>Signature:</b>
+
+```go
+func OmitByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.OmitByValues(m, []int{4, 5})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
+
 ### <span id="Intersect">Intersect</span>

 <p>Iterates over maps, return a new map of key and value pairs in all given maps.</p>
@@ -193,6 +404,7 @@ package main

 import (
    "fmt"
+    "sort"
    "github.com/duke-git/lancet/v2/maputil"
 )

@@ -313,6 +525,7 @@ package main

 import (
    "fmt"
+    "sort"
    "github.com/duke-git/lancet/v2/maputil"
 )

@@ -335,6 +548,300 @@ func main() {
 }
 ```

+### <span id="KeysBy">KeysBy</span>
+
+<p>Creates a slice whose element is the result of function mapper invoked by every map's key.</p>
+
+<b>Signature:</b>
+
+```go
+func KeysBy[K comparable, V any, T any](m map[K]V, mapper func(item K) T) []T
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "a",
+        3: "b",
+    }
+
+    keys := maputil.KeysBy(m, func(n int) int {
+        return n + 1
+    })
+
+    sort.Ints(keys)
+
+    fmt.Println(keys)
+
+    // Output:
+    // [2 3 4]
+}
+```
+
+### <span id="ValuesBy">ValuesBy</span>
+
+<p>Creates a slice whose element is the result of function mapper invoked by every map's value.</p>
+
+<b>Signature:</b>
+
+```go
+func ValuesBy[K comparable, V any, T any](m map[K]V, mapper func(item V) T) []T
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+    values := maputil.ValuesBy(m, func(v string) string {
+        switch v {
+        case "a":
+            return "a-1"
+        case "b":
+            return "b-2"
+        case "c":
+            return "c-3"
+        default:
+            return ""
+        }
+    })
+
+    sort.Strings(values)
+
+    fmt.Println(values)
+
+    // Output:
+    // [a-1 b-2 c-3]
+}
+```
+
+
+### <span id="MapKeys">MapKeys</span>
+
+<p>Transforms a map to other type map by manipulating it's keys.</p>
+
+<b>Signature:</b>
+
+```go
+func MapKeys[K comparable, V any, T comparable](m map[K]V, iteratee func(key K, value V) T) map[T]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+
+    result := maputil.MapKeys(m, func(k int, _ string) string {
+        return strconv.Itoa(k)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[1:a 2:b 3:c]
+}
+```
+
+### <span id="MapValues">MapValues</span>
+
+<p>Transforms a map to other type map by manipulating it's values.</p>
+
+<b>Signature:</b>
+
+```go
+func MapValues[K comparable, V any, T any](m map[K]V, iteratee func(key K, value V) T) map[K]T
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+
+    result := maputil.MapValues(m, func(k int, v string) string {
+        return v + strconv.Itoa(k)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[1:a1 2:b2 3:c3]
+}
+```
+
+
+### <span id="Entry">Entry</span>
+
+<p>Transforms a map into array of key/value pairs.</p>
+
+<b>Signature:</b>
+
+```go
+type Entry[K comparable, V any] struct {
+    Key   K
+    Value V
+}
+func Entries[K comparable, V any](m map[K]V) []Entry[K, V]
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+    }
+
+    result := maputil.Entries(m)
+
+    sort.Slice(result, func(i, j int) bool {
+        return result[i].Value < result[j].Value
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // [{a 1} {b 2} {c 3}]
+}
+```
+
+
+### <span id="FromEntries">FromEntries</span>
+
+<p>Creates a map based on a slice of key/value pairs.</p>
+
+<b>Signature:</b>
+
+```go
+type Entry[K comparable, V any] struct {
+    Key   K
+    Value V
+}
+func FromEntries[K comparable, V any](entries []Entry[K, V]) map[K]V
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    result := maputil.FromEntries([]Entry[string, int]{
+        {Key: "a", Value: 1},
+        {Key: "b", Value: 2},
+        {Key: "c", Value: 3},
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
+### <span id="Transform">Transform</span>
+
+<p>Transform a map to another type map.</p>
+
+<b>Signature:</b>
+
+```go
+func Transform[K1 comparable, V1 any, K2 comparable, V2 any](m map[K1]V1, iteratee func(key K1, value V1) (K2, V2)) map[K2]V2
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+    }
+
+    result := Transform(m, func(k string, v int) (string, string) {
+        return k, strconv.Itoa(v)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
+
 ### <span id="IsDisjoint">IsDisjoint</span>

 <p>Checks two maps are disjoint if they have no keys in common</p>
--- a/docs/maputil_zh-CN.md
+++ b/docs/maputil_zh-CN.md
@@ -24,11 +24,23 @@ import (

 -   [ForEach](#ForEach)
 -   [Filter](#Filter)
+-   [FilterByKeys](#FilterByKeys)
+-   [FilterByValues](#FilterByValues)
+-   [OmitBy](#OmitBy)
+-   [OmitByKeys](#OmitByKeys)
+-   [OmitByValues](#OmitByValues)
 -   [Intersect](#Intersect)
 -   [Keys](#Keys)
+-   [Values](#Values)
+-   [KeysBy](#KeysBy)
+-   [ValuesBy](#ValuesBy)
+-   [MapKeys](#MapKeys)
+-   [MapValues](#MapValues)
+-   [Entries](#Entries)
+-   [FromEntries](#FromEntries)
+-   [Transform](#Transform)
 -   [Merge](#Merge)
 -   [Minus](#Minus)
-   [Values](#Values)
 -   [IsDisjoint](#IsDisjoint)

 <div STYLE="page-break-after: always;"></div>
@@ -78,7 +90,7 @@ func main() {

 ### <span id="Filter">Filter</span>

-<p>迭代map中的每对key和value, 返回符合predicate函数的key, value</p>
+<p>迭代map中的每对key和value, 返回符合predicate函数的key, value。</p>

 <b>函数签名:</b>

@@ -121,6 +133,203 @@ func main() {
 }
 ```

+### <span id="FilterByKeys">FilterByKeys</span>
+
+<p>迭代map, 返回一个新map，其key都是给定的key值。</p>
+
+<b>函数签名:</b>
+
+```go
+func FilterByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.FilterByKeys(m, []string{"a", "b"})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2]
+}
+```
+
+
+### <span id="FilterByValues">FilterByValues</span>
+
+<p>迭代map, 返回一个新map，其value都是给定的value值。</p>
+
+<b>函数签名:</b>
+
+```go
+func FilterByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.FilterByValues(m, []int{3, 4})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[c:3 d:4]
+}
+```
+
+
+### <span id="OmitBy">OmitBy</span>
+
+<p>Filter的反向操作, 迭代map中的每对key和value, 删除符合predicate函数的key, value, 返回新map。</p>
+
+<b>函数签名:</b>
+
+```go
+func OmitBy[K comparable, V any](m map[K]V, predicate func(key K, value V) bool) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+    isEven := func(_ string, value int) bool {
+        return value%2 == 0
+    }
+
+    result := maputil.OmitBy(m, isEven)
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 c:3 e:5]
+}
+```
+
+
+### <span id="OmitByKeys">OmitByKeys</span>
+
+<p>FilterByKeys的反向操作, 迭代map, 返回一个新map，其key不包括给定的key值。</p>
+
+<b>函数签名:</b>
+
+```go
+func OmitByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.OmitByKeys(m, []string{"a", "b"})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[c:3 d:4 e:5]
+}
+```
+
+
+### <span id="OmitByValues">OmitByValues</span>
+
+<p>FilterByValues的反向操作, 迭代map, 返回一个新map，其value不包括给定的value值。</p>
+
+<b>函数签名:</b>
+
+```go
+func OmitByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+        "d": 4,
+        "e": 5,
+    }
+
+    result := maputil.OmitByValues(m, []int{4, 5})
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
 ### <span id="Intersect">Intersect</span>

 <p>多个map的交集操作</p>
@@ -333,6 +542,299 @@ func main() {
 }
 ```

+### <span id="KeysBy">KeysBy</span>
+
+<p>创建一个切片，其元素是每个map的key调用mapper函数的结果。</p>
+
+<b>函数签名:</b>
+
+```go
+func KeysBy[K comparable, V any, T any](m map[K]V, mapper func(item K) T) []T
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "a",
+        3: "b",
+    }
+
+    keys := maputil.KeysBy(m, func(n int) int {
+        return n + 1
+    })
+
+    sort.Ints(keys)
+
+    fmt.Println(keys)
+
+    // Output:
+    // [2 3 4]
+}
+```
+
+### <span id="ValuesBy">ValuesBy</span>
+
+<p>创建一个切片，其元素是每个map的value调用mapper函数的结果。</p>
+
+<b>函数签名:</b>
+
+```go
+func ValuesBy[K comparable, V any, T any](m map[K]V, mapper func(item V) T) []T
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+    values := maputil.ValuesBy(m, func(v string) string {
+        switch v {
+        case "a":
+            return "a-1"
+        case "b":
+            return "b-2"
+        case "c":
+            return "c-3"
+        default:
+            return ""
+        }
+    })
+
+    sort.Strings(values)
+
+    fmt.Println(values)
+
+    // Output:
+    // [a-1 b-2 c-3]
+}
+```
+
+
+### <span id="MapKeys">MapKeys</span>
+
+<p>操作map的每个key，然后转为新的map。</p>
+
+<b>函数签名:</b>
+
+```go
+func MapKeys[K comparable, V any, T comparable](m map[K]V, iteratee func(key K, value V) T) map[T]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+
+    result := maputil.MapKeys(m, func(k int, _ string) string {
+        return strconv.Itoa(k)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[1:a 2:b 3:c]
+}
+```
+
+### <span id="MapValues">MapValues</span>
+
+<p>操作map的每个value，然后转为新的map。</p>
+
+<b>函数签名:</b>
+
+```go
+func MapValues[K comparable, V any, T any](m map[K]V, iteratee func(key K, value V) T) map[K]T
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[int]string{
+        1: "a",
+        2: "b",
+        3: "c",
+    }
+
+    result := maputil.MapValues(m, func(k int, v string) string {
+        return v + strconv.Itoa(k)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[1:a1 2:b2 3:c3]
+}
+```
+
+
+### <span id="Entry">Entry</span>
+
+<p>将map转换为键/值对切片。</p>
+
+<b>函数签名:</b>
+
+```go
+type Entry[K comparable, V any] struct {
+    Key   K
+    Value V
+}
+func Entries[K comparable, V any](m map[K]V) []Entry[K, V]
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "sort"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+    }
+
+    result := maputil.Entries(m)
+
+    sort.Slice(result, func(i, j int) bool {
+        return result[i].Value < result[j].Value
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // [{a 1} {b 2} {c 3}]
+}
+```
+
+
+### <span id="FromEntries">FromEntries</span>
+
+<p>基于键/值对的切片创建map。</p>
+
+<b>函数签名:</b>
+
+```go
+type Entry[K comparable, V any] struct {
+    Key   K
+    Value V
+}
+func FromEntries[K comparable, V any](entries []Entry[K, V]) map[K]V
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    result := maputil.FromEntries([]Entry[string, int]{
+        {Key: "a", Value: 1},
+        {Key: "b", Value: 2},
+        {Key: "c", Value: 3},
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
+### <span id="Transform">Transform</span>
+
+<p>将map转换为其他类型的map。</p>
+
+<b>函数签名:</b>
+
+```go
+func Transform[K1 comparable, V1 any, K2 comparable, V2 any](m map[K1]V1, iteratee func(key K1, value V1) (K2, V2)) map[K2]V2
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "strconv"
+    "github.com/duke-git/lancet/v2/maputil"
+)
+
+func main() {
+    m := map[string]int{
+        "a": 1,
+        "b": 2,
+        "c": 3,
+    }
+
+    result := Transform(m, func(k string, v int) (string, string) {
+        return k, strconv.Itoa(v)
+    })
+
+    fmt.Println(result)
+
+    // Output:
+    // map[a:1 b:2 c:3]
+}
+```
+
 ### <span id="IsDisjoint">IsDisjoint</span>

 <p>验证两个map是否具有不同的key</p>
--- a/docs/slice.md
+++ b/docs/slice.md
@@ -24,6 +24,7 @@ import (

 -   [AppendIfAbsent](#AppendIfAbsent)
 -   [Contain](#Contain)
+-   [ContainBy](#ContainBy)
 -   [ContainSubSlice](#ContainSubSlice)
 -   [Chunk](#Chunk)
 -   [Compact](#Compact)
@@ -35,6 +36,9 @@ import (
 -   [DifferenceWith](#DifferenceWith)
 -   [DeleteAt](#DeleteAt)
 -   [Drop](#Drop)
+-   [DropRight](#DropRight)
+-   [DropWhile](#DropWhile)
+-   [DropRightWhile](#DropRightWhile)
 -   [Equal](#Equal)
 -   [EqualWith](#EqualWith)
 -   [Every](#Every)
@@ -53,6 +57,8 @@ import (
 -   [IndexOf](#IndexOf)
 -   [LastIndexOf](#LastIndexOf)
 -   [Map](#Map)
+-   [FilterMap](#FilterMap)
+-   [FlatMap](#FlatMap)
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce](#Reduce)
@@ -60,6 +66,10 @@ import (
 -   [ReplaceAll](#ReplaceAll)
 -   [Repeat](#Repeat)
 -   [Shuffle](#Shuffle)
+-   [IsAscending](#IsAscending)
+-   [IsDescending](#IsDescending)
+-   [IsSorted](#IsSorted)
+-   [IsSortedByKey](#IsSortedByKey)
 -   [Sort](#Sort)
 -   [SortBy](#SortBy)
 -   [SortByField<sup>deprecated</sup>](#SortByField)
@@ -142,6 +152,51 @@ func main() {
 }
 ```

+### <span id="ContainBy">ContainBy</span>
+
+<p>returns true if predicate function return true.</p>
+
+<b>Signature:</b>
+
+```go
+func ContainBy[T any](slice []T, predicate func(item T) bool) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    type foo struct {
+		A string
+		B int
+	}
+
+	array1 := []foo{{A: "1", B: 1}, {A: "2", B: 2}}
+	result1 := slice.ContainBy(array1, func(f foo) bool { return f.A == "1" && f.B == 1 })
+	result2 := slice.ContainBy(array1, func(f foo) bool { return f.A == "2" && f.B == 1 })
+
+	array2 := []string{"a", "b", "c"}
+	result3 := slice.ContainBy(array2, func(t string) bool { return t == "a" })
+	result4 := slice.ContainBy(array2, func(t string) bool { return t == "d" })
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// false
+	// true
+	// false
+}
+```
+
 ### <span id="ContainSubSlice">ContainSubSlice</span>

 <p>Check if the slice contain subslice or not.</p>
@@ -487,7 +542,7 @@ func main() {

 ### <span id="Drop">Drop</span>

-<p>Creates a slice with `n` elements dropped from the beginning when n > 0, or `n` elements dropped from the ending when n < 0.</p>
+<p>Drop n elements from the start of a slice.</p>

 <b>Signature:</b>

@@ -505,20 +560,139 @@ import (

 func main() {
    result1 := slice.Drop([]string{"a", "b", "c"}, 0)
-    result2 := slice.Drop([]string{"a", "b", "c"}, 1)
-    result3 := slice.Drop([]string{"a", "b", "c"}, -1)
-    result4 := slice.Drop([]string{"a", "b", "c"}, 4)
+	result2 := slice.Drop([]string{"a", "b", "c"}, 1)
+	result3 := slice.Drop([]string{"a", "b", "c"}, -1)
+	result4 := slice.Drop([]string{"a", "b", "c"}, 4)

-    fmt.Println(result1)
-    fmt.Println(result2)
-    fmt.Println(result3)
-    fmt.Println(result4)
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)

-    // Output:
-    // [a b c]
-    // [b c]
-    // [a b]
-    // []
+	// Output:
+	// [a b c]
+	// [b c]
+	// [a b c]
+	// []
+}
+```
+
+### <span id="DropRight">DropRight</span>
+
+<p>Drop n elements from the end of a slice.</p>
+
+<b>Signature:</b>
+
+```go
+func DropRight[T any](slice []T, n int) []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.DropRight([]string{"a", "b", "c"}, 0)
+	result2 := slice.DropRight([]string{"a", "b", "c"}, 1)
+	result3 := slice.DropRight([]string{"a", "b", "c"}, -1)
+	result4 := slice.DropRight([]string{"a", "b", "c"}, 4)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// [a b c]
+	// [a b]
+	// [a b c]
+	// []
+}
+```
+
+### <span id="DropWhile">DropWhile</span>
+
+<p>Drop n elements from the start of a slice while predicate function returns true.</p>
+
+<b>Signature:</b>
+
+```go
+func DropWhile[T any](slice []T, predicate func(item T) bool) []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.DropWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := slice.DropWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := slice.DropWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [2 3 4 5]
+	// []
+	// [1 2 3 4 5]
+}
+```
+
+### <span id="DropRightWhile">DropRightWhile</span>
+
+<p>Drop n elements from the end of a slice while predicate function returns true.</p>
+
+<b>Signature:</b>
+
+```go
+func DropRightWhile[T any](slice []T, predicate func(item T) bool) []T
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    numbers := []int{1, 2, 3, 4, 5}
+
+	result1 := slice.DropRightWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := slice.DropRightWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := slice.DropRightWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [1 2]
+	// []
+	// [1 2 3 4 5]
 }
 ```

@@ -1126,6 +1300,76 @@ func main() {
 }
 ```

+### <span id="FilterMap">FilterMap</span>
+
+<p>Returns a slice which apply both filtering and mapping to the given slice. iteratee callback function should returntwo values: 1, mapping result. 2, whether the result element should be included or not.</p>
+
+<b>Signature:</b>
+
+```go
+func FilterMap[T any, U any](slice []T, iteratee func(index int, item T) (U, bool)) []U
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5}
+
+	getEvenNumStr := func(i, num int) (string, bool) {
+		if num%2 == 0 {
+			return strconv.FormatInt(int64(num), 10), true
+		}
+		return "", false
+	}
+
+	result := slice.FilterMap(nums, getEvenNumStr)
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"2", "4"}
+}
+```
+
+### <span id="FlatMap">FlatMap</span>
+
+<p>Manipulates a slice and transforms and flattens it to a slice of another type.</p>
+
+<b>Signature:</b>
+
+```go
+func FlatMap[T any, U any](slice []T, iteratee func(index int, item T) []U) []U
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4}
+
+	result := slice.FlatMap(nums, func(i int, num int) []string {
+		s := "hi-" + strconv.FormatInt(int64(num), 10)
+		return []string{s}
+	})
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"hi-1", "hi-2", "hi-3", "hi-4"}
+}
+```
+
 ### <span id="Merge">Merge</span>

 <p>Merge all given slices into one slice.</p>
@@ -1341,13 +1585,155 @@ func main() {
    nums := []int{1, 2, 3, 4, 5}
    result := slice.Shuffle(nums)

-    fmt.Println(res) 
-    
+    fmt.Println(res)
+
    // Output:
    // [3 1 5 4 2] (random order)
 }
 ```

+### <span id="IsAscending">IsAscending</span>
+
+<p>Checks if a slice is ascending order.</p>
+
+<b>Signature:</b>
+
+```go
+func IsAscending[T constraints.Ordered](slice []T) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsAscending([]int{1, 2, 3, 4, 5})
+	result2 := slice.IsAscending([]int{5, 4, 3, 2, 1})
+	result3 := slice.IsAscending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+```
+
+### <span id="IsDescending">IsDescending</span>
+
+<p>Checks if a slice is descending order.</p>
+
+<b>Signature:</b>
+
+```go
+func IsDescending[T constraints.Ordered](slice []T) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsDescending([]int{5, 4, 3, 2, 1})
+	result2 := slice.IsDescending([]int{1, 2, 3, 4, 5})
+	result3 := slice.IsDescending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+```
+
+### <span id="IsSorted">IsSorted</span>
+
+<p>Checks if a slice is sorted (ascending or descending).</p>
+
+<b>Signature:</b>
+
+```go
+func IsSorted[T constraints.Ordered](slice []T) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsSorted([]int{5, 4, 3, 2, 1})
+	result2 := slice.IsSorted([]int{1, 2, 3, 4, 5})
+	result3 := slice.IsSorted([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+```
+
+### <span id="IsSortedByKey">IsSortedByKey</span>
+
+<p>Checks if a slice is sorted by iteratee function.</p>
+
+<b>Signature:</b>
+
+```go
+func IsSortedByKey[T any, K constraints.Ordered](slice []T, iteratee func(item T) K) bool
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsSortedByKey([]string{"a", "ab", "abc"}, func(s string) int {
+		return len(s)
+	})
+	result2 := slice.IsSortedByKey([]string{"abc", "ab", "a"}, func(s string) int {
+		return len(s)
+	})
+	result3 := slice.IsSortedByKey([]string{"abc", "a", "ab"}, func(s string) int {
+		return len(s)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+```
+
 ### <span id="Sort">Sort</span>

 <p>Sorts a slice of any ordered type(number or string), use quick sort algrithm. Default sort order is ascending (asc), if want descending order, set param `sortOrder` to `desc`. Ordered type: number(all ints uints floats) or string.
--- a/docs/slice_zh-CN.md
+++ b/docs/slice_zh-CN.md
@@ -24,6 +24,7 @@ import (

 -   [AppendIfAbsent](#AppendIfAbsent)
 -   [Contain](#Contain)
+-   [ContainBy](#ContainBy)
 -   [ContainSubSlice](#ContainSubSlice)
 -   [Chunk](#Chunk)
 -   [Compact](#Compact)
@@ -35,6 +36,9 @@ import (
 -   [DifferenceWith](#DifferenceWith)
 -   [DeleteAt](#DeleteAt)
 -   [Drop](#Drop)
+-   [DropRight](#DropRight)
+-   [DropWhile](#DropWhile)
+-   [DropRightWhile](#DropRightWhile)
 -   [Every](#Every)
 -   [Equal](#Equal)
 -   [EqualWith](#EqualWith)
@@ -53,6 +57,8 @@ import (
 -   [IndexOf](#IndexOf)
 -   [LastIndexOf](#LastIndexOf)
 -   [Map](#Map)
+-   [FilterMap](#FilterMap)
+-   [FlatMap](#FlatMap)
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce](#Reduce)
@@ -60,6 +66,10 @@ import (
 -   [ReplaceAll](#ReplaceAll)
 -   [Repeat](#Repeat)
 -   [Shuffle](#Shuffle)
+-   [IsAscending](#IsAscending)
+-   [IsDescending](#IsDescending)
+-   [IsSorted](#IsSorted)
+-   [IsSortedByKey](#IsSortedByKey)
 -   [Sort](#Sort)
 -   [SortBy](#SortBy)
 -   [SortByField<sup>deprecated</sup>](#SortByField)
@@ -142,6 +152,51 @@ func main() {
 }
 ```

+### <span id="ContainBy">ContainBy</span>
+
+<p>根据predicate函数判断切片是否包含某个值。</p>
+
+<b>函数签名:</b>
+
+```go
+func ContainBy[T any](slice []T, predicate func(item T) bool) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    type foo struct {
+		A string
+		B int
+	}
+
+	array1 := []foo{{A: "1", B: 1}, {A: "2", B: 2}}
+	result1 := slice.ContainBy(array1, func(f foo) bool { return f.A == "1" && f.B == 1 })
+	result2 := slice.ContainBy(array1, func(f foo) bool { return f.A == "2" && f.B == 1 })
+
+	array2 := []string{"a", "b", "c"}
+	result3 := slice.ContainBy(array2, func(t string) bool { return t == "a" })
+	result4 := slice.ContainBy(array2, func(t string) bool { return t == "d" })
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// false
+	// true
+	// false
+}
+```
+
 ### <span id="ContainSubSlice">ContainSubSlice</span>

 <p>判断slice是否包含subslice</p>
@@ -486,9 +541,10 @@ func main() {
 }
 ```

+
 ### <span id="Drop">Drop</span>

-<p>创建一个切片，当n > 0时从开头删除n个元素，或者当n < 0时从结尾删除n个元素</p>
+<p>从切片的头部删除n个元素。</p>

 <b>函数签名:</b>

@@ -506,20 +562,139 @@ import (

 func main() {
    result1 := slice.Drop([]string{"a", "b", "c"}, 0)
-    result2 := slice.Drop([]string{"a", "b", "c"}, 1)
-    result3 := slice.Drop([]string{"a", "b", "c"}, -1)
-    result4 := slice.Drop([]string{"a", "b", "c"}, 4)
+	result2 := slice.Drop([]string{"a", "b", "c"}, 1)
+	result3 := slice.Drop([]string{"a", "b", "c"}, -1)
+	result4 := slice.Drop([]string{"a", "b", "c"}, 4)

-    fmt.Println(result1)
-    fmt.Println(result2)
-    fmt.Println(result3)
-    fmt.Println(result4)
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)

-    // Output:
-    // [a b c]
-    // [b c]
-    // [a b]
-    // []
+	// Output:
+	// [a b c]
+	// [b c]
+	// [a b c]
+	// []
+}
+```
+
+### <span id="DropRight">DropRight</span>
+
+<p>从切片的尾部删除n个元素。</p>
+
+<b>函数签名:</b>
+
+```go
+func DropRight[T any](slice []T, n int) []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.DropRight([]string{"a", "b", "c"}, 0)
+	result2 := slice.DropRight([]string{"a", "b", "c"}, 1)
+	result3 := slice.DropRight([]string{"a", "b", "c"}, -1)
+	result4 := slice.DropRight([]string{"a", "b", "c"}, 4)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// [a b c]
+	// [a b]
+	// [a b c]
+	// []
+}
+```
+
+### <span id="DropWhile">DropWhile</span>
+
+<p>从切片的头部删除n个元素，这个n个元素满足predicate函数返回true。</p>
+
+<b>函数签名:</b>
+
+```go
+func DropWhile[T any](slice []T, predicate func(item T) bool) []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.DropWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := slice.DropWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := slice.DropWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [2 3 4 5]
+	// []
+	// [1 2 3 4 5]
+}
+```
+
+### <span id="DropRightWhile">DropRightWhile</span>
+
+<p>从切片的尾部删除n个元素，这个n个元素满足predicate函数返回true。</p>
+
+<b>函数签名:</b>
+
+```go
+func DropRightWhile[T any](slice []T, predicate func(item T) bool) []T
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    numbers := []int{1, 2, 3, 4, 5}
+
+	result1 := slice.DropRightWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := slice.DropRightWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := slice.DropRightWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [1 2]
+	// []
+	// [1 2 3 4 5]
 }
 ```

@@ -1127,6 +1302,76 @@ func main() {
 }
 ```

+### <span id="FilterMap">FilterMap</span>
+
+<p>返回一个将filter和map操作应用于给定切片的切片。 iteratee回调函数应该返回两个值：1，结果值。2，结果值是否应该被包含在返回的切片中。</p>
+
+<b>函数签名:</b>
+
+```go
+func FilterMap[T any, U any](slice []T, iteratee func(index int, item T) (U, bool)) []U
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5}
+
+	getEvenNumStr := func(i, num int) (string, bool) {
+		if num%2 == 0 {
+			return strconv.FormatInt(int64(num), 10), true
+		}
+		return "", false
+	}
+
+	result := slice.FilterMap(nums, getEvenNumStr)
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"2", "4"}
+}
+```
+
+### <span id="FlatMap">FlatMap</span>
+
+<p>将切片转换为其它类型切片。</p>
+
+<b>函数签名:</b>
+
+```go
+func FlatMap[T any, U any](slice []T, iteratee func(index int, item T) []U) []U
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4}
+
+	result := slice.FlatMap(nums, func(i int, num int) []string {
+		s := "hi-" + strconv.FormatInt(int64(num), 10)
+		return []string{s}
+	})
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"hi-1", "hi-2", "hi-3", "hi-4"}
+}
+```
+
 ### <span id="Merge">Merge</span>

 <p>合并多个切片（不会消除重复元素).</p>
@@ -1349,6 +1594,148 @@ func main() {
 }
 ```

+### <span id="IsAscending">IsAscending</span>
+
+<p>检查切片元素是否按升序排列。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsAscending[T constraints.Ordered](slice []T) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsAscending([]int{1, 2, 3, 4, 5})
+	result2 := slice.IsAscending([]int{5, 4, 3, 2, 1})
+	result3 := slice.IsAscending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+```
+
+### <span id="IsDescending">IsDescending</span>
+
+<p>检查切片元素是否按降序排列。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsDescending[T constraints.Ordered](slice []T) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsDescending([]int{5, 4, 3, 2, 1})
+	result2 := slice.IsDescending([]int{1, 2, 3, 4, 5})
+	result3 := slice.IsDescending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+```
+
+### <span id="IsSorted">IsSorted</span>
+
+<p>检查切片元素是否是有序的（升序或降序）。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsSorted[T constraints.Ordered](slice []T) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsSorted([]int{5, 4, 3, 2, 1})
+	result2 := slice.IsSorted([]int{1, 2, 3, 4, 5})
+	result3 := slice.IsSorted([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+```
+
+### <span id="IsSortedByKey">IsSortedByKey</span>
+
+<p>通过iteratee函数，检查切片元素是否是有序的。</p>
+
+<b>函数签名:</b>
+
+```go
+func IsSortedByKey[T any, K constraints.Ordered](slice []T, iteratee func(item T) K) bool
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    result1 := slice.IsSortedByKey([]string{"a", "ab", "abc"}, func(s string) int {
+		return len(s)
+	})
+	result2 := slice.IsSortedByKey([]string{"abc", "ab", "a"}, func(s string) int {
+		return len(s)
+	})
+	result3 := slice.IsSortedByKey([]string{"abc", "a", "ab"}, func(s string) int {
+		return len(s)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+```
+
 ### <span id="Sort">Sort</span>

 <p>对任何有序类型（数字或字符串）的切片进行排序，使用快速排序算法。 默认排序顺序为升序 (asc)，如果需要降序，请将参数 `sortOrder` 设置为 `desc`。 Ordered类型：数字（所有整数浮点数）或字符串。</p>
--- a/docs/strutil.md
+++ b/docs/strutil.md
@@ -33,8 +33,9 @@ import (
 -   [UpperKebabCase](#UpperKebabCase)
 -   [LowerFirst](#LowerFirst)
 -   [UpperFirst](#UpperFirst)
-   [PadEnd](#PadEnd)
+-   [Pad](#Pad)
 -   [PadStart](#PadStart)
+-   [PadEnd](#PadEnd)
 -   [Reverse](#Reverse)
 -   [SnakeCase](#SnakeCase)
 -   [UpperSnakeCase](#UpperSnakeCase)
@@ -42,6 +43,8 @@ import (
 -   [Substring](#Substring)
 -   [Wrap](#Wrap)
 -   [Unwrap](#Unwrap)
+-   [SplitWords](#SplitWords)
+-   [WordCount](#WordCount)

 <div STYLE="page-break-after: always;"></div>

@@ -449,6 +452,51 @@ func main() {
 }
 ```

+### <span id="Pad">Pad</span>
+
+<p>Pads string on the left and right side if it's shorter than size.</p>
+
+<b>Signature:</b>
+
+```go
+func Pad(source string, size int, padStr string) string
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.Pad("foo", 1, "bar")
+    result2 := strutil.Pad("foo", 2, "bar")
+    result3 := strutil.Pad("foo", 3, "bar")
+    result4 := strutil.Pad("foo", 4, "bar")
+    result5 := strutil.Pad("foo", 5, "bar")
+    result6 := strutil.Pad("foo", 6, "bar")
+    result7 := strutil.Pad("foo", 7, "bar")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+    fmt.Println(result7)
+    // Output:
+    // foo
+    // foo
+    // foo
+    // foob
+    // bfoob
+    // bfooba
+    // bafooba
+}
+```
+
 ### <span id="PadEnd">PadEnd</span>

 <p>Pads string on the right side if it's shorter than size.</p>
@@ -802,3 +850,91 @@ func main() {
    // *foo*
 }
 ```
+
+
+### <span id="SplitWords">SplitWords</span>
+
+<p>Splits a string into words, word only contains alphabetic characters.</p>
+
+<b>Signature:</b>
+
+```go
+func SplitWords(s string) []string
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.SplitWords("a word")
+    result2 := strutil.SplitWords("I'am a programmer")
+    result3 := strutil.SplitWords("Bonjour, je suis programmeur")
+    result4 := strutil.SplitWords("a -b-c' 'd'e")
+    result5 := strutil.SplitWords("你好，我是一名码农")
+    result6 := strutil.SplitWords("こんにちは，私はプログラマーです")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+
+    // Output:
+    // [a word]
+    // [I'am a programmer]
+    // [Bonjour je suis programmeur]
+    // [a b-c' d'e]
+    // []
+    // []
+}
+```
+
+
+### <span id="WordCount">WordCount</span>
+
+<p>Return the number of meaningful word, word only contains alphabetic characters.</p>
+
+<b>Signature:</b>
+
+```go
+func WordCount(s string) int
+```
+
+<b>Example:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.WordCount("a word")
+    result2 := strutil.WordCount("I'am a programmer")
+    result3 := strutil.WordCount("Bonjour, je suis programmeur")
+    result4 := strutil.WordCount("a -b-c' 'd'e")
+    result5 := strutil.WordCount("你好，我是一名码农")
+    result6 := strutil.WordCount("こんにちは，私はプログラマーです")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+
+    // Output:
+    // 2
+    // 3
+    // 4
+    // 3
+    // 0
+    // 0
+}
+```
--- a/docs/strutil_zh-CN.md
+++ b/docs/strutil_zh-CN.md
@@ -33,6 +33,7 @@ import (
 -   [UpperKebabCase](#UpperKebabCase)
 -   [LowerFirst](#LowerFirst)
 -   [UpperFirst](#UpperFirst)
+-   [Pad](#Pad)
 -   [PadEnd](#PadEnd)
 -   [PadStart](#PadStart)
 -   [Reverse](#Reverse)
@@ -42,6 +43,8 @@ import (
 -   [Substring](#Substring)
 -   [Wrap](#Wrap)
 -   [Unwrap](#Unwrap)
+-   [SplitWords](#SplitWords)
+-   [WordCount](#WordCount)

 <div STYLE="page-break-after: always;"></div>

@@ -449,6 +452,51 @@ func main() {
 }
 ```

+### <span id="Pad">Pad</span>
+
+<p>如果字符串长度短于size，则在左右两侧填充字符串。</p>
+
+<b>函数签名:</b>
+
+```go
+func Pad(source string, size int, padStr string) string
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.Pad("foo", 1, "bar")
+    result2 := strutil.Pad("foo", 2, "bar")
+    result3 := strutil.Pad("foo", 3, "bar")
+    result4 := strutil.Pad("foo", 4, "bar")
+    result5 := strutil.Pad("foo", 5, "bar")
+    result6 := strutil.Pad("foo", 6, "bar")
+    result7 := strutil.Pad("foo", 7, "bar")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+    fmt.Println(result7)
+    // Output:
+    // foo
+    // foo
+    // foo
+    // foob
+    // bfoob
+    // bfooba
+    // bafooba
+}
+```
+
 ### <span id="PadEnd">PadEnd</span>

 <p>如果字符串长度短于size，则在右侧填充字符串。</p>
@@ -802,3 +850,90 @@ func main() {
    // *foo*
 }
 ```
+
+### <span id="SplitWords">SplitWords</span>
+
+<p>将字符串拆分为单词，只支持字母字符单词。</p>
+
+<b>函数签名:</b>
+
+```go
+func SplitWords(s string) []string
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.SplitWords("a word")
+    result2 := strutil.SplitWords("I'am a programmer")
+    result3 := strutil.SplitWords("Bonjour, je suis programmeur")
+    result4 := strutil.SplitWords("a -b-c' 'd'e")
+    result5 := strutil.SplitWords("你好，我是一名码农")
+    result6 := strutil.SplitWords("こんにちは，私はプログラマーです")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+
+    // Output:
+    // [a word]
+    // [I'am a programmer]
+    // [Bonjour je suis programmeur]
+    // [a b-c' d'e]
+    // []
+    // []
+}
+```
+
+
+### <span id="WordCount">WordCount</span>
+
+<p>返回有意义单词的数量，只支持字母字符单词。</p>
+
+<b>函数签名:</b>
+
+```go
+func WordCount(s string) int
+```
+
+<b>示例:</b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/strutil"
+)
+
+func main() {
+    result1 := strutil.WordCount("a word")
+    result2 := strutil.WordCount("I'am a programmer")
+    result3 := strutil.WordCount("Bonjour, je suis programmeur")
+    result4 := strutil.WordCount("a -b-c' 'd'e")
+    result5 := strutil.WordCount("你好，我是一名码农")
+    result6 := strutil.WordCount("こんにちは，私はプログラマーです")
+
+    fmt.Println(result1)
+    fmt.Println(result2)
+    fmt.Println(result3)
+    fmt.Println(result4)
+    fmt.Println(result5)
+    fmt.Println(result6)
+
+    // Output:
+    // 2
+    // 3
+    // 4
+    // 3
+    // 0
+    // 0
+}
+```
--- a/docs/xerror.md
+++ b/docs/xerror.md
@@ -22,20 +22,40 @@ import (

 ## Index

+-   [New](#New)
+-   [Wrap](#Wrap)
 -   [Unwrap](#Unwrap)
+-   [XError_Wrap](#XError_Wrap)
+-   [XError_Unwrap](#XError_Unwrap)
+-   [XError_With](#XError_With)
+-   [XError_Is](#XError_Is)
+-   [XError_Id](#XError_Id)
+-   [XError_Values](#XError_Values)
+-   [XError_StackTrace](#XError_StackTrace)
+-   [XError_Info](#XError_Info)
+-   [XError_Error](#XError_Error)
+-   [TryUnwrap](#TryUnwrap)

 <div STYLE="page-break-after: always;"></div>

 ## Documentation

-### <span id="Unwrap">Unwrap</span>
+### <span id="New">New</span>

-<p>Unwrap if err is nil then it returns a valid value. If err is not nil, Unwrap panics with err.</p>
+<p>Creates a new XError pointer instance with message.</p>

 <b>Signature:</b>

 ```go
-func Unwrap[T any](val T, err error) T
+type XError struct {
+    id      string
+    message string
+    stack   *stack
+    cause   error
+    values  map[string]any
+}
+
+func New(format string, args ...any) *XError
 ```

 <b>Example:</b>
@@ -49,7 +69,407 @@ import (
 )

 func main() {
-    result1 := xerror.Unwrap(strconv.Atoi("42"))
+    err := xerror.New("error")
+    fmt.Println(err.Error())
+
+    // Output:
+    // error
+}
+```
+
+### <span id="Wrap">Wrap</span>
+
+<p>Creates a new XError pointer instance based on error object, and add message.</p>
+
+<b>Signature:</b>
+
+```go
+func Wrap(cause error, message ...any) *XError
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("wrong password")
+    wrapErr := xerror.Wrap(err, "error")
+
+    fmt.Println(wrapErr.Error())
+
+    // Output:
+    // error: wrong password
+}
+```
+
+### <span id="Unwrap">Unwrap</span>
+
+<p>Returns unwrapped XError from err by errors.As. If no XError, returns nil.</p>
+
+<b>Signature:</b>
+
+```go
+func Unwrap(err error) *XError
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/pkg/errors"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").With("level", "high")
+    wrapErr := errors.Wrap(err1, "oops")
+
+    err := xerror.Unwrap(wrapErr)
+
+    values := err.Values()
+    fmt.Println(values["level"])
+
+    // Output:
+    // high
+}
+```
+
+### <span id="XError_Wrap">XError_Wrap</span>
+
+<p>Creates a new XError and copy message and id to new one.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Wrap(cause error) *XError
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("wrong password")
+    wrapErr := xerror.Wrap(err, "error")
+
+    fmt.Println(wrapErr.Error())
+
+    // Output:
+    // error: wrong password
+}
+```
+
+### <span id="XError_Unwrap">XError_Unwrap</span>
+
+<p>Compatible with github.com/pkg/errors.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Unwrap() error
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").With("level", "high")
+    err2 := err1.Wrap(errors.New("invalid username"))
+
+    err := err2.Unwrap()
+
+    fmt.Println(err.Error())
+
+    // Output:
+    // invalid username
+}
+```
+
+### <span id="XError_With">XError_With</span>
+
+<p>Adds key and value related to the XError object.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) With(key string, value any) *XError
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error").With("level", "high")
+
+    errLevel := err.Values()["level"]
+
+    fmt.Println(errLevel)
+
+    // Output:
+    // high
+}
+```
+
+### <span id="XError_Id">XError_Id</span>
+
+<p>Sets XError object id to check equality in XError.Is.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Id(id string) *XError
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").Id("e001")
+    err2 := xerror.New("error").Id("e001")
+    err3 := xerror.New("error").Id("e003")
+
+    equal := err1.Is(err2)
+    notEqual := err1.Is(err3)
+
+    fmt.Println(equal)
+    fmt.Println(notEqual)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="XError_Is">XError_Is</span>
+
+<p>Checks if target error is XError and Error.id of two errors are matched.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Is(target error) bool
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").Id("e001")
+    err2 := xerror.New("error").Id("e001")
+    err3 := xerror.New("error").Id("e003")
+
+    equal := err1.Is(err2)
+    notEqual := err1.Is(err3)
+
+    fmt.Println(equal)
+    fmt.Println(notEqual)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="XError_Values">XError_Values</span>
+
+<p>Returns map of key and value that is set by With. All wrapped xerror.XError key and values will be merged. Key and values of wrapped error is overwritten by upper xerror.XError.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Values() map[string]any
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error").With("level", "high")
+
+    errLevel := err.Values()["level"]
+
+    fmt.Println(errLevel)
+
+    // Output:
+    // high
+}
+```
+
+
+### <span id="XError_StackTrace">XError_StackTrace</span>
+
+<p>Returns stack trace which is compatible with pkg/errors.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) StackTrace() StackTrace
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error")
+
+    stacks := err.Stacks()
+
+    fmt.Println(stacks[0].Func)
+    fmt.Println(stacks[0].Line)
+
+    containFile := strings.Contains(stacks[0].File, "xxx.go")
+    fmt.Println(containFile)
+}
+```
+
+
+### <span id="XError_Info">XError_Info</span>
+
+<p>Returns information of xerror, which can be printed.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Info() *errInfo
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    cause := errors.New("error")
+    err := xerror.Wrap(cause, "invalid username").Id("e001").With("level", "high")
+
+    errInfo := err.Info()
+
+    fmt.Println(errInfo.Id)
+    fmt.Println(errInfo.Cause)
+    fmt.Println(errInfo.Values["level"])
+    fmt.Println(errInfo.Message)
+
+    // Output:
+    // e001
+    // error
+    // high
+    // invalid username
+}
+```
+
+
+### <span id="XError_Error">XError_Error</span>
+
+<p>Error implements standard error interface.</p>
+
+<b>Signature:</b>
+
+```go
+func (e *XError) Error() string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error")
+    fmt.Println(err.Error())
+
+    // Output:
+    // error
+}
+```
+### <span id="TryUnwrap">TryUnwrap</span>
+
+<p>TryUnwrap if err is nil then it returns a valid value. If err is not nil, Unwrap panics with err.</p>
+
+<b>Signature:</b>
+
+```go
+func TryUnwrap[T any](val T, err error) T
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    result1 := xerror.TryUnwrap(strconv.Atoi("42"))
    fmt.Println(result1)

    _, err := strconv.Atoi("4o2")
@@ -59,7 +479,7 @@ func main() {
        fmt.Println(result2)
    }()

-    xerror.Unwrap(strconv.Atoi("4o2"))
+    xerror.TryUnwrap(strconv.Atoi("4o2"))

    // Output:
    // 42
--- a/docs/xerror_zh-CN.md
+++ b/docs/xerror_zh-CN.md
@@ -22,20 +22,40 @@ import (

 ## 目录

+-   [New](#New)
+-   [Wrap](#Wrap)
 -   [Unwrap](#Unwrap)
+-   [XError_Wrap](#XError_Wrap)
+-   [XError_Unwrap](#XError_Unwrap)
+-   [XError_With](#XError_With)
+-   [XError_Is](#XError_Is)
+-   [XError_Id](#XError_Id)
+-   [XError_Values](#XError_Values)
+-   [XError_StackTrace](#XError_StackTrace)
+-   [XError_Info](#XError_Info)
+-   [XError_Error](#XError_Error)
+-   [TryUnwrap](#TryUnwrap)

 <div STYLE="page-break-after: always;"></div>

 ## 文档

-### <span id="Unwrap">Unwrap</span>
+### <span id="New">New</span>

-<p>检查error, 如果err为nil则展开，则它返回一个有效值，如果err不是nil则Unwrap使用err发生panic。</p>
+<p>创建XError对象实例。</p>

 <b>函数签名:</b>

 ```go
-func Unwrap[T any](val T, err error) T
+type XError struct {
+    id      string
+    message string
+    stack   *stack
+    cause   error
+    values  map[string]any
+}
+
+func New(format string, args ...any) *XError
 ```

 <b>示例:</b>
@@ -49,7 +69,408 @@ import (
 )

 func main() {
-    result1 := xerror.Unwrap(strconv.Atoi("42"))
+    err := xerror.New("error")
+    fmt.Println(err.Error())
+
+    // Output:
+    // error
+}
+```
+
+### <span id="Wrap">Wrap</span>
+
+<p>根据error对象创建XError对象实例，可添加message。</p>
+
+<b>函数签名:</b>
+
+```go
+func Wrap(cause error, message ...any) *XError
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("wrong password")
+    wrapErr := xerror.Wrap(err, "error")
+
+    fmt.Println(wrapErr.Error())
+
+    // Output:
+    // error: wrong password
+}
+```
+
+### <span id="Unwrap">Unwrap</span>
+
+<p>从error对象中解构出XError。</p>
+
+<b>函数签名:</b>
+
+```go
+func Unwrap(err error) *XError
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/pkg/errors"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").With("level", "high")
+    wrapErr := errors.Wrap(err1, "oops")
+
+    err := xerror.Unwrap(wrapErr)
+
+    values := err.Values()
+    fmt.Println(values["level"])
+
+    // Output:
+    // high
+}
+```
+
+### <span id="XError_Wrap">XError_Wrap</span>
+
+<p>创建新的XError对象并将消息和id复制到新的对象中。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Wrap(cause error) *XError
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("wrong password")
+    wrapErr := xerror.Wrap(err, "error")
+
+    fmt.Println(wrapErr.Error())
+
+    // Output:
+    // error: wrong password
+}
+```
+
+### <span id="XError_Unwrap">XError_Unwrap</span>
+
+<p>解构XEerror为error对象。适配github.com/pkg/errors。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Unwrap() error
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").With("level", "high")
+    err2 := err1.Wrap(errors.New("invalid username"))
+
+    err := err2.Unwrap()
+
+    fmt.Println(err.Error())
+
+    // Output:
+    // invalid username
+}
+```
+
+### <span id="XError_With">XError_With</span>
+
+<p>添加与XError对象的键和值。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) With(key string, value any) *XError
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error").With("level", "high")
+
+    errLevel := err.Values()["level"]
+
+    fmt.Println(errLevel)
+
+    // Output:
+    // high
+}
+```
+
+### <span id="XError_Id">XError_Id</span>
+
+<p>设置XError对象的id。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Id(id string) *XError
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").Id("e001")
+    err2 := xerror.New("error").Id("e001")
+    err3 := xerror.New("error").Id("e003")
+
+    equal := err1.Is(err2)
+    notEqual := err1.Is(err3)
+
+    fmt.Println(equal)
+    fmt.Println(notEqual)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="XError_Is">XError_Is</span>
+
+<p>检查目标error是否为XError，两个错误中的error.id是否匹配。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Is(target error) bool
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err1 := xerror.New("error").Id("e001")
+    err2 := xerror.New("error").Id("e001")
+    err3 := xerror.New("error").Id("e003")
+
+    equal := err1.Is(err2)
+    notEqual := err1.Is(err3)
+
+    fmt.Println(equal)
+    fmt.Println(notEqual)
+
+    // Output:
+    // true
+    // false
+}
+```
+
+### <span id="XError_Values">XError_Values</span>
+
+<p>返回由With设置的键和值的映射。将合并所有XError键和值。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Values() map[string]any
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error").With("level", "high")
+
+    errLevel := err.Values()["level"]
+
+    fmt.Println(errLevel)
+
+    // Output:
+    // high
+}
+```
+
+
+### <span id="XError_StackTrace">XError_StackTrace</span>
+
+<p>返回与pkg/error兼容的堆栈信息。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) StackTrace() StackTrace
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error")
+
+    stacks := err.Stacks()
+
+    fmt.Println(stacks[0].Func)
+    fmt.Println(stacks[0].Line)
+
+    containFile := strings.Contains(stacks[0].File, "xxx.go")
+    fmt.Println(containFile)
+}
+```
+
+
+### <span id="XError_Info">XError_Info</span>
+
+<p>返回可打印的XError对象信息。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Info() *errInfo
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    cause := errors.New("error")
+    err := xerror.Wrap(cause, "invalid username").Id("e001").With("level", "high")
+
+    errInfo := err.Info()
+
+    fmt.Println(errInfo.Id)
+    fmt.Println(errInfo.Cause)
+    fmt.Println(errInfo.Values["level"])
+    fmt.Println(errInfo.Message)
+
+    // Output:
+    // e001
+    // error
+    // high
+    // invalid username
+}
+```
+
+
+### <span id="XError_Error">XError_Error</span>
+
+<p>实现标准库的error接口。</p>
+
+<b>函数签名:</b>
+
+```go
+func (e *XError) Error() string
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    err := xerror.New("error")
+    fmt.Println(err.Error())
+
+    // Output:
+    // error
+}
+```
+
+### <span id="TryUnwrap">TryUnwrap</span>
+
+<p>检查error, 如果err为nil则展开，则它返回一个有效值，如果err不是nil则TryUnwrap使用err发生panic。</p>
+
+<b>函数签名:</b>
+
+```go
+func TryUnwrap[T any](val T, err error) T
+```
+
+<b>示例:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/xerror"
+)
+
+func main() {
+    result1 := xerror.TryUnwrap(strconv.Atoi("42"))
    fmt.Println(result1)

    _, err := strconv.Atoi("4o2")
@@ -59,7 +480,7 @@ func main() {
        fmt.Println(result2)
    }()

-    xerror.Unwrap(strconv.Atoi("4o2"))
+    xerror.TryUnwrap(strconv.Atoi("4o2"))

    // Output:
    // 42
--- a/maputil/map.go
+++ b/maputil/map.go
@@ -4,7 +4,11 @@
 // Package maputil includes some functions to manipulate map.
 package maputil

-import "reflect"
+import (
+	"reflect"
+
+	"github.com/duke-git/lancet/v2/slice"
+)

 // Keys returns a slice of the map's keys.
 // Play: https://go.dev/play/p/xNB5bTb97Wd
@@ -34,6 +38,30 @@ func Values[K comparable, V any](m map[K]V) []V {
 	return values
 }

+// KeysBy creates a slice whose element is the result of function mapper invoked by every map's key.
+// Play: todo
+func KeysBy[K comparable, V any, T any](m map[K]V, mapper func(item K) T) []T {
+	keys := make([]T, 0, len(m))
+
+	for k := range m {
+		keys = append(keys, mapper(k))
+	}
+
+	return keys
+}
+
+// ValuesBy creates a slice whose element is the result of function mapper invoked by every map's value.
+// Play: todo
+func ValuesBy[K comparable, V any, T any](m map[K]V, mapper func(item V) T) []T {
+	keys := make([]T, 0, len(m))
+
+	for _, v := range m {
+		keys = append(keys, mapper(v))
+	}
+
+	return keys
+}
+
 // Merge maps, next key will overwrite previous key.
 // Play: https://go.dev/play/p/H95LENF1uB-
 func Merge[K comparable, V any](maps ...map[K]V) map[K]V {
@@ -69,6 +97,71 @@ func Filter[K comparable, V any](m map[K]V, predicate func(key K, value V) bool)
 	return result
 }

+// FilterByKeys iterates over map, return a new map whose keys are all given keys.
+// Play: todo
+func FilterByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V {
+	result := make(map[K]V)
+
+	for k, v := range m {
+		if slice.Contain(keys, k) {
+			result[k] = v
+		}
+	}
+	return result
+}
+
+// FilterByValues iterates over map, return a new map whose values are all given values.
+// Play: todo
+func FilterByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V {
+	result := make(map[K]V)
+
+	for k, v := range m {
+		if slice.Contain(values, v) {
+			result[k] = v
+		}
+	}
+	return result
+}
+
+// OmitBy is the opposite of Filter, removes all the map elements for which the predicate function returns true.
+// Play: todo
+func OmitBy[K comparable, V any](m map[K]V, predicate func(key K, value V) bool) map[K]V {
+	result := make(map[K]V)
+
+	for k, v := range m {
+		if !predicate(k, v) {
+			result[k] = v
+		}
+	}
+	return result
+}
+
+// OmitByKeys the opposite of FilterByKeys, extracts all the map elements which keys are not omitted.
+// Play: todo
+func OmitByKeys[K comparable, V any](m map[K]V, keys []K) map[K]V {
+	result := make(map[K]V)
+
+	for k, v := range m {
+		if !slice.Contain(keys, k) {
+			result[k] = v
+		}
+	}
+	return result
+}
+
+// OmitByValues the opposite of FilterByValues. remov all elements whose value are in the give slice.
+// Play: todo
+func OmitByValues[K comparable, V comparable](m map[K]V, values []V) map[K]V {
+	result := make(map[K]V)
+
+	for k, v := range m {
+		if !slice.Contain(values, v) {
+			result[k] = v
+		}
+	}
+	return result
+}
+
 // Intersect iterates over maps, return a new map of key and value pairs in all given maps.
 // Play: https://go.dev/play/p/Zld0oj3sjcC
 func Intersect[K comparable, V any](maps ...map[K]V) map[K]V {
@@ -126,3 +219,73 @@ func IsDisjoint[K comparable, V any](mapA, mapB map[K]V) bool {
 	}
 	return true
 }
+
+// Entry is a key/value pairs.
+type Entry[K comparable, V any] struct {
+	Key   K
+	Value V
+}
+
+// Entries transforms a map into array of key/value pairs.
+// Play: todo
+func Entries[K comparable, V any](m map[K]V) []Entry[K, V] {
+	entries := make([]Entry[K, V], 0, len(m))
+
+	for k, v := range m {
+		entries = append(entries, Entry[K, V]{
+			Key:   k,
+			Value: v,
+		})
+	}
+
+	return entries
+}
+
+// FromEntries creates a map based on a slice of key/value pairs
+// Play: todo
+func FromEntries[K comparable, V any](entries []Entry[K, V]) map[K]V {
+	result := make(map[K]V, len(entries))
+
+	for _, v := range entries {
+		result[v.Key] = v.Value
+	}
+
+	return result
+}
+
+// Transform a map to another type map.
+// Play: todo
+func Transform[K1 comparable, V1 any, K2 comparable, V2 any](m map[K1]V1, iteratee func(key K1, value V1) (K2, V2)) map[K2]V2 {
+	result := make(map[K2]V2, len(m))
+
+	for k1, v1 := range m {
+		k2, v2 := iteratee(k1, v1)
+		result[k2] = v2
+	}
+
+	return result
+}
+
+// MapKeys transforms a map to other type map by manipulating it's keys.
+// Play: todo
+func MapKeys[K comparable, V any, T comparable](m map[K]V, iteratee func(key K, value V) T) map[T]V {
+	result := make(map[T]V, len(m))
+
+	for k, v := range m {
+		result[iteratee(k, v)] = v
+	}
+
+	return result
+}
+
+// MapValues transforms a map to other type map by manipulating it's values.
+// Play: todo
+func MapValues[K comparable, V any, T any](m map[K]V, iteratee func(key K, value V) T) map[K]T {
+	result := make(map[K]T, len(m))
+
+	for k, v := range m {
+		result[k] = iteratee(k, v)
+	}
+
+	return result
+}
--- a/maputil/map_example_test.go
+++ b/maputil/map_example_test.go
@@ -3,6 +3,7 @@ package maputil
 import (
 	"fmt"
 	"sort"
+	"strconv"
 )

 func ExampleKeys() {
@@ -41,6 +42,51 @@ func ExampleValues() {
 	// [a a b c d]
 }

+func ExampleKeysBy() {
+	m := map[int]string{
+		1: "a",
+		2: "a",
+		3: "b",
+	}
+
+	keys := KeysBy(m, func(n int) int {
+		return n + 1
+	})
+
+	sort.Ints(keys)
+
+	fmt.Println(keys)
+
+	// Output:
+	// [2 3 4]
+}
+
+func ExampleValuesBy() {
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+	values := ValuesBy(m, func(v string) string {
+		switch v {
+		case "a":
+			return "a-1"
+		case "b":
+			return "b-2"
+		case "c":
+			return "c-3"
+		default:
+			return ""
+		}
+	})
+
+	sort.Strings(values)
+
+	fmt.Println(values)
+
+	// Output:
+	// [a-1 b-2 c-3]
+}
 func ExampleMerge() {
 	m1 := map[int]string{
 		1: "a",
@@ -99,6 +145,40 @@ func ExampleFilter() {
 	// map[b:2 d:4]
 }

+func ExampleFilterByKeys() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	result := FilterByKeys(m, []string{"a", "b"})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[a:1 b:2]
+}
+
+func ExampleFilterByValues() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	result := FilterByValues(m, []int{3, 4})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[c:3 d:4]
+}
+
 func ExampleIntersect() {
 	m1 := map[string]int{
 		"a": 1,
@@ -179,3 +259,141 @@ func ExampleIsDisjoint() {
 	// true
 	// false
 }
+
+func ExampleEntries() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+	}
+
+	result := Entries(m)
+
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].Value < result[j].Value
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// [{a 1} {b 2} {c 3}]
+}
+
+func ExampleFromEntries() {
+
+	result := FromEntries([]Entry[string, int]{
+		{Key: "a", Value: 1},
+		{Key: "b", Value: 2},
+		{Key: "c", Value: 3},
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[a:1 b:2 c:3]
+}
+
+func ExampleTransform() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+	}
+
+	result := Transform(m, func(k string, v int) (string, string) {
+		return k, strconv.Itoa(v)
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[a:1 b:2 c:3]
+}
+
+func ExampleMapKeys() {
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+
+	result := MapKeys(m, func(k int, _ string) string {
+		return strconv.Itoa(k)
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[1:a 2:b 3:c]
+}
+
+func ExampleMapValues() {
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+
+	result := MapValues(m, func(k int, v string) string {
+		return v + strconv.Itoa(k)
+	})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[1:a1 2:b2 3:c3]
+}
+
+func ExampleOmitBy() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+	isEven := func(_ string, value int) bool {
+		return value%2 == 0
+	}
+
+	result := OmitBy(m, isEven)
+
+	fmt.Println(result)
+
+	// Output:
+	// map[a:1 c:3 e:5]
+}
+
+func ExampleOmitByKeys() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	result := OmitByKeys(m, []string{"a", "b"})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[c:3 d:4 e:5]
+}
+
+func ExampleOmitByValues() {
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	result := OmitByValues(m, []int{4, 5})
+
+	fmt.Println(result)
+
+	// Output:
+	// map[a:1 b:2 c:3]
+}
--- a/maputil/map_test.go
+++ b/maputil/map_test.go
@@ -2,6 +2,7 @@ package maputil

 import (
 	"sort"
+	"strconv"
 	"testing"

 	"github.com/duke-git/lancet/v2/internal"
@@ -41,6 +42,51 @@ func TestValues(t *testing.T) {
 	assert.Equal([]string{"a", "a", "b", "c", "d"}, values)
 }

+func TestKeysBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestKeysBy")
+
+	m := map[int]string{
+		1: "a",
+		2: "a",
+		3: "b",
+	}
+
+	keys := KeysBy(m, func(n int) int {
+		return n + 1
+	})
+
+	sort.Ints(keys)
+
+	assert.Equal([]int{2, 3, 4}, keys)
+}
+
+func TestValuesBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestValuesBy")
+
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+
+	values := ValuesBy(m, func(v string) string {
+		switch v {
+		case "a":
+			return "a-1"
+		case "b":
+			return "b-2"
+		case "c":
+			return "c-3"
+		default:
+			return ""
+		}
+	})
+
+	sort.Strings(values)
+
+	assert.Equal([]string{"a-1", "b-2", "c-3"}, values)
+}
+
 func TestMerge(t *testing.T) {
 	assert := internal.NewAssert(t, "TestMerge")

@@ -104,6 +150,107 @@ func TestFilter(t *testing.T) {
 	}, acturl)
 }

+func TestFilterByKeys(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFilterByKeys")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	acturl := FilterByKeys(m, []string{"a", "b"})
+
+	assert.Equal(map[string]int{
+		"a": 1,
+		"b": 2,
+	}, acturl)
+}
+
+func TestFilterByValues(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFilterByValues")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	acturl := FilterByValues(m, []int{3, 4})
+
+	assert.Equal(map[string]int{
+		"c": 3,
+		"d": 4,
+	}, acturl)
+}
+
+func TestOmitBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestOmitBy")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+	isEven := func(_ string, value int) bool {
+		return value%2 == 0
+	}
+
+	acturl := OmitBy(m, isEven)
+
+	assert.Equal(map[string]int{
+		"a": 1,
+		"c": 3,
+		"e": 5,
+	}, acturl)
+}
+
+func TestOmitByKeys(t *testing.T) {
+	assert := internal.NewAssert(t, "TestOmitByKeys")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	acturl := OmitByKeys(m, []string{"a", "b"})
+
+	assert.Equal(map[string]int{
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}, acturl)
+}
+
+func TestOmitByValues(t *testing.T) {
+	assert := internal.NewAssert(t, "TestOmitByValues")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+		"d": 4,
+		"e": 5,
+	}
+
+	acturl := OmitByValues(m, []int{4, 5})
+
+	assert.Equal(map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+	}, acturl)
+}
+
 func TestIntersect(t *testing.T) {
 	assert := internal.NewAssert(t, "TestIntersect")

@@ -170,3 +317,104 @@ func TestIsDisjoint(t *testing.T) {

 	assert.Equal(false, IsDisjoint(m1, m3))
 }
+
+func TestEntries(t *testing.T) {
+	assert := internal.NewAssert(t, "TestEntries")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+	}
+
+	result := Entries(m)
+
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].Value < result[j].Value
+	})
+
+	expected := []Entry[string, int]{{Key: "a", Value: 1}, {Key: "b", Value: 2}, {Key: "c", Value: 3}}
+
+	assert.Equal(expected, result)
+}
+
+func TestFromEntries(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFromEntries")
+
+	result := FromEntries([]Entry[string, int]{
+		{Key: "a", Value: 1},
+		{Key: "b", Value: 2},
+		{Key: "c", Value: 3},
+	})
+
+	assert.Equal(3, len(result))
+	assert.Equal(1, result["a"])
+	assert.Equal(2, result["b"])
+	assert.Equal(3, result["c"])
+}
+
+func TestTransform(t *testing.T) {
+	assert := internal.NewAssert(t, "TestTransform")
+
+	m := map[string]int{
+		"a": 1,
+		"b": 2,
+		"c": 3,
+	}
+
+	result := Transform(m, func(k string, v int) (string, string) {
+		return k, strconv.Itoa(v)
+	})
+
+	expected := map[string]string{
+		"a": "1",
+		"b": "2",
+		"c": "3",
+	}
+
+	assert.Equal(expected, result)
+}
+
+func TestMapKeys(t *testing.T) {
+	assert := internal.NewAssert(t, "TestMapKeys")
+
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+
+	result := MapKeys(m, func(k int, _ string) string {
+		return strconv.Itoa(k)
+	})
+
+	expected := map[string]string{
+		"1": "a",
+		"2": "b",
+		"3": "c",
+	}
+
+	assert.Equal(expected, result)
+}
+
+func TestMapValues(t *testing.T) {
+	assert := internal.NewAssert(t, "TestMapKeys")
+
+	m := map[int]string{
+		1: "a",
+		2: "b",
+		3: "c",
+	}
+
+	result := MapValues(m, func(k int, v string) string {
+		return v + strconv.Itoa(k)
+	})
+
+	expected := map[int]string{
+		1: "a1",
+		2: "b2",
+		3: "c3",
+	}
+
+	assert.Equal(expected, result)
+}
--- a/random/random.go
+++ b/random/random.go
@@ -13,12 +13,16 @@ import (
 )

 const (
-	NUMERAL       = "0123456789"
-	LOWER_LETTERS = "abcdefghijklmnopqrstuvwxyz"
-	UPPER_LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-	LETTERS       = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	Numeral       = "0123456789"
+	LowwerLetters = "abcdefghijklmnopqrstuvwxyz"
+	UpperLetters  = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	Letters       = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 )

+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
 // RandInt generate random int between min and max, maybe min,  not be max.
 // Play: https://go.dev/play/p/pXyyAAI5YxD
 func RandInt(min, max int) int {
@@ -28,9 +32,12 @@ func RandInt(min, max int) int {
 	if max < min {
 		min, max = max, min
 	}
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))

-	return r.Intn(max-min) + min
+	// fix: https://github.com/duke-git/lancet/issues/75
+	// r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	// return r.Intn(max-min) + min
+
+	return rand.Intn(max-min) + min
 }

 // RandBytes generate random byte slice.
@@ -51,40 +58,42 @@ func RandBytes(length int) []byte {
 // RandString generate random string of specified length.
 // Play: https://go.dev/play/p/W2xvRUXA7Mi
 func RandString(length int) string {
-	return random(LETTERS, length)
+	return random(Letters, length)
 }

 // RandUpper generate a random upper case string.
 // Play: https://go.dev/play/p/29QfOh0DVuh
 func RandUpper(length int) string {
-	return random(UPPER_LETTERS, length)
+	return random(UpperLetters, length)
 }

 // RandLower generate a random lower case string.
 // Play: https://go.dev/play/p/XJtZ471cmtI
 func RandLower(length int) string {
-	return random(LOWER_LETTERS, length)
+	return random(LowwerLetters, length)
 }

 // RandNumeral generate a random numeral string of specified length.
 // Play: https://go.dev/play/p/g4JWVpHsJcf
 func RandNumeral(length int) string {
-	return random(NUMERAL, length)
+	return random(Numeral, length)
 }

 // RandNumeralOrLetter generate a random numeral or letter string.
 // Play: https://go.dev/play/p/19CEQvpx2jD
 func RandNumeralOrLetter(length int) string {
-	return random(NUMERAL+LETTERS, length)
+	return random(Numeral+Letters, length)
 }

 // random generate a random string based on given string range.
 func random(s string, length int) string {
 	b := make([]byte, length)
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	// fix: https://github.com/duke-git/lancet/issues/75
+	// r := rand.New(rand.NewSource(time.Now().UnixNano()))

 	for i := range b {
-		b[i] = s[r.Int63()%int64(len(s))]
+		b[i] = s[rand.Int63()%int64(len(s))]
 	}

 	return string(b)
--- a/slice/slice.go
+++ b/slice/slice.go
@@ -6,7 +6,6 @@ package slice

 import (
 	"fmt"
-	"math"
 	"math/rand"
 	"reflect"
 	"sort"
@@ -23,7 +22,7 @@ var (
 )

 // Contain check if the target value is in the slice or not.
-// Play: https://go.dev/play/p/_454yEHcNjf
+// Play: todo
 func Contain[T comparable](slice []T, target T) bool {
 	for _, item := range slice {
 		if item == target {
@@ -34,6 +33,17 @@ func Contain[T comparable](slice []T, target T) bool {
 	return false
 }

+// ContainBy returns true if predicate function return true.
+func ContainBy[T any](slice []T, predicate func(item T) bool) bool {
+	for _, item := range slice {
+		if predicate(item) {
+			return true
+		}
+	}
+
+	return false
+}
+
 // ContainSubSlice check if the slice contain a given subslice or not.
 // Play: https://go.dev/play/p/bcuQ3UT6Sev
 func ContainSubSlice[T comparable](slice, subSlice []T) bool {
@@ -422,6 +432,35 @@ func Map[T any, U any](slice []T, iteratee func(index int, item T) U) []U {
 	return result
 }

+// FilterMap returns a slice which apply both filtering and mapping to the given slice.
+// iteratee callback function should returntwo values:
+// 1, mapping result.
+// 2, whether the result element should be included or not
+// Play: todo
+func FilterMap[T any, U any](slice []T, iteratee func(index int, item T) (U, bool)) []U {
+	result := []U{}
+
+	for i, v := range slice {
+		if a, ok := iteratee(i, v); ok {
+			result = append(result, a)
+		}
+	}
+
+	return result
+}
+
+// FlatMap manipulates a slice and transforms and flattens it to a slice of another type.
+// Play: todo
+func FlatMap[T any, U any](slice []T, iteratee func(index int, item T) []U) []U {
+	result := make([]U, 0, len(slice))
+
+	for i, v := range slice {
+		result = append(result, iteratee(i, v)...)
+	}
+
+	return result
+}
+
 // Reduce creates an slice of values by running each element of slice thru iteratee function.
 // Play: https://go.dev/play/p/_RfXJJWIsIm
 func Reduce[T any](slice []T, iteratee func(index int, item1, item2 T) T, initial T) T {
@@ -559,24 +598,72 @@ func DeleteAt[T any](slice []T, start int, end ...int) []T {
 	return slice
 }

-// Drop creates a slice with `n` elements dropped from the beginning when n > 0, or `n` elements dropped from the ending when n < 0.
-// Play: https://go.dev/play/p/pJ-d6MUWcvK
+// Drop drop n elements from the start of a slice.
+// Play: https://go.dev/play/p/jnPO2yQsT8H
 func Drop[T any](slice []T, n int) []T {
 	size := len(slice)

-	if size == 0 || n == 0 {
-		return slice
-	}
-
-	if math.Abs(float64(n)) >= float64(size) {
+	if size <= n {
 		return []T{}
 	}

-	if n < 0 {
-		return slice[0 : size+n]
+	if n <= 0 {
+		return slice
 	}

-	return slice[n:size]
+	result := make([]T, 0, size-n)
+
+	return append(result, slice[n:]...)
+}
+
+// DropRight drop n elements from the end of a slice.
+// Play: https://go.dev/play/p/8bcXvywZezG
+func DropRight[T any](slice []T, n int) []T {
+	size := len(slice)
+
+	if size <= n {
+		return []T{}
+	}
+
+	if n <= 0 {
+		return slice
+	}
+
+	result := make([]T, 0, size-n)
+
+	return append(result, slice[:size-n]...)
+}
+
+// DropWhile drop n elements from the start of a slice while predicate function returns true.
+// Play: https://go.dev/play/p/4rt252UV_qs
+func DropWhile[T any](slice []T, predicate func(item T) bool) []T {
+	i := 0
+
+	for ; i < len(slice); i++ {
+		if !predicate(slice[i]) {
+			break
+		}
+	}
+
+	result := make([]T, 0, len(slice)-i)
+
+	return append(result, slice[i:]...)
+}
+
+// DropRightWhile drop n elements from the end of a slice while predicate function returns true.
+// Play: https://go.dev/play/p/6wyK3zMY56e
+func DropRightWhile[T any](slice []T, predicate func(item T) bool) []T {
+	i := len(slice) - 1
+
+	for ; i >= 0; i-- {
+		if !predicate(slice[i]) {
+			break
+		}
+	}
+
+	result := make([]T, 0, i+1)
+
+	return append(result, slice[:i+1]...)
 }

 // InsertAt insert the value or other slice into slice at index.
@@ -783,6 +870,64 @@ func Shuffle[T any](slice []T) []T {
 	return slice
 }

+// IsAscending checks if a slice is ascending order.
+// Play: https://go.dev/play/p/9CtsFjet4SH
+func IsAscending[T constraints.Ordered](slice []T) bool {
+	for i := 1; i < len(slice); i++ {
+		if slice[i-1] > slice[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// IsDescending checks if a slice is descending order.
+// Play: https://go.dev/play/p/U_LljFXma14
+func IsDescending[T constraints.Ordered](slice []T) bool {
+	for i := 1; i < len(slice); i++ {
+		if slice[i-1] < slice[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// IsSorted checks if a slice is sorted(ascending or descending).
+// Play: https://go.dev/play/p/nCE8wPLwSA-
+func IsSorted[T constraints.Ordered](slice []T) bool {
+	return IsAscending(slice) || IsDescending(slice)
+}
+
+// IsSortedByKey checks if a slice is sorted by iteratee function.
+// Play: https://go.dev/play/p/tUoGB7DOHI4
+func IsSortedByKey[T any, K constraints.Ordered](slice []T, iteratee func(item T) K) bool {
+	size := len(slice)
+
+	isAscending := func(data []T) bool {
+		for i := 0; i < size-1; i++ {
+			if iteratee(data[i]) > iteratee(data[i+1]) {
+				return false
+			}
+		}
+
+		return true
+	}
+
+	isDescending := func(data []T) bool {
+		for i := 0; i < size-1; i++ {
+			if iteratee(data[i]) < iteratee(data[i+1]) {
+				return false
+			}
+		}
+
+		return true
+	}
+
+	return isAscending(slice) || isDescending(slice)
+}
+
 // Sort sorts a slice of any ordered type(number or string), use quick sort algrithm.
 // default sort order is ascending (asc), if want descending order, set param `sortOrder` to `desc`.
 // Play: https://go.dev/play/p/V9AVjzf_4Fk
--- a/slice/slice_example_test.go
+++ b/slice/slice_example_test.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"math"
 	"reflect"
+	"strconv"
 )

 func ExampleContain() {
@@ -18,6 +19,32 @@ func ExampleContain() {
 	// false
 }

+func ExampleContainBy() {
+	type foo struct {
+		A string
+		B int
+	}
+
+	array1 := []foo{{A: "1", B: 1}, {A: "2", B: 2}}
+	result1 := ContainBy(array1, func(f foo) bool { return f.A == "1" && f.B == 1 })
+	result2 := ContainBy(array1, func(f foo) bool { return f.A == "2" && f.B == 1 })
+
+	array2 := []string{"a", "b", "c"}
+	result3 := ContainBy(array2, func(t string) bool { return t == "a" })
+	result4 := ContainBy(array2, func(t string) bool { return t == "d" })
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// true
+	// false
+	// true
+	// false
+}
+
 func ExampleContainSubSlice() {
 	result1 := ContainSubSlice([]string{"a", "b", "c"}, []string{"a", "b"})
 	result2 := ContainSubSlice([]string{"a", "b", "c"}, []string{"a", "d"})
@@ -367,6 +394,38 @@ func ExampleMap() {
 	// [2 3 4]
 }

+func ExampleFilterMap() {
+	nums := []int{1, 2, 3, 4, 5}
+
+	getEvenNumStr := func(i, num int) (string, bool) {
+		if num%2 == 0 {
+			return strconv.FormatInt(int64(num), 10), true
+		}
+		return "", false
+	}
+
+	result := FilterMap(nums, getEvenNumStr)
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"2", "4"}
+}
+
+func ExampleFlatMap() {
+	nums := []int{1, 2, 3, 4}
+
+	result := FlatMap(nums, func(i int, num int) []string {
+		s := "hi-" + strconv.FormatInt(int64(num), 10)
+		return []string{s}
+	})
+
+	fmt.Printf("%#v", result)
+
+	// Output:
+	// []string{"hi-1", "hi-2", "hi-3", "hi-4"}
+}
+
 func ExampleReduce() {
 	nums := []int{1, 2, 3}

@@ -482,10 +541,74 @@ func ExampleDrop() {
 	// Output:
 	// [a b c]
 	// [b c]
-	// [a b]
+	// [a b c]
 	// []
 }

+func ExampleDropRight() {
+	result1 := DropRight([]string{"a", "b", "c"}, 0)
+	result2 := DropRight([]string{"a", "b", "c"}, 1)
+	result3 := DropRight([]string{"a", "b", "c"}, -1)
+	result4 := DropRight([]string{"a", "b", "c"}, 4)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// [a b c]
+	// [a b]
+	// [a b c]
+	// []
+}
+
+func ExampleDropWhile() {
+	numbers := []int{1, 2, 3, 4, 5}
+
+	result1 := DropWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := DropWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := DropWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [2 3 4 5]
+	// []
+	// [1 2 3 4 5]
+}
+
+func ExampleDropRightWhile() {
+	numbers := []int{1, 2, 3, 4, 5}
+
+	result1 := DropRightWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	result2 := DropRightWhile(numbers, func(n int) bool {
+		return true
+	})
+	result3 := DropRightWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// [1 2]
+	// []
+	// [1 2 3 4 5]
+}
+
 func ExampleInsertAt() {
 	result1 := InsertAt([]string{"a", "b", "c"}, 0, "1")
 	result2 := InsertAt([]string{"a", "b", "c"}, 1, "1")
@@ -621,6 +744,75 @@ func ExampleReverse() {
 	// [d c b a]
 }

+func ExampleIsAscending() {
+
+	result1 := IsAscending([]int{1, 2, 3, 4, 5})
+	result2 := IsAscending([]int{5, 4, 3, 2, 1})
+	result3 := IsAscending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+
+func ExampleIsDescending() {
+
+	result1 := IsDescending([]int{5, 4, 3, 2, 1})
+	result2 := IsDescending([]int{1, 2, 3, 4, 5})
+	result3 := IsDescending([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// false
+	// false
+}
+
+func ExampleIsSorted() {
+
+	result1 := IsSorted([]int{1, 2, 3, 4, 5})
+	result2 := IsSorted([]int{5, 4, 3, 2, 1})
+	result3 := IsSorted([]int{2, 1, 3, 4, 5})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+
+func ExampleIsSortedByKey() {
+	result1 := IsSortedByKey([]string{"a", "ab", "abc"}, func(s string) int {
+		return len(s)
+	})
+	result2 := IsSortedByKey([]string{"abc", "ab", "a"}, func(s string) int {
+		return len(s)
+	})
+	result3 := IsSortedByKey([]string{"abc", "a", "ab"}, func(s string) int {
+		return len(s)
+	})
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+
+	// Output:
+	// true
+	// true
+	// false
+}
+
 func ExampleSort() {
 	nums := []int{1, 4, 3, 2, 5}

--- a/slice/slice_test.go
+++ b/slice/slice_test.go
@@ -3,6 +3,7 @@ package slice
 import (
 	"fmt"
 	"math"
+	"strconv"
 	"testing"

 	"github.com/duke-git/lancet/v2/internal"
@@ -19,6 +20,28 @@ func TestContain(t *testing.T) {
 	assert.Equal(true, Contain([]int{1, 2, 3}, 1))
 }

+func TestContainBy(t *testing.T) {
+	assert := internal.NewAssert(t, "TestContainBy")
+
+	type foo struct {
+		A string
+		B int
+	}
+
+	array1 := []foo{{A: "1", B: 1}, {A: "2", B: 2}}
+	result1 := ContainBy(array1, func(f foo) bool { return f.A == "1" && f.B == 1 })
+	result2 := ContainBy(array1, func(f foo) bool { return f.A == "2" && f.B == 1 })
+
+	array2 := []string{"a", "b", "c"}
+	result3 := ContainBy(array2, func(t string) bool { return t == "a" })
+	result4 := ContainBy(array2, func(t string) bool { return t == "d" })
+
+	assert.Equal(true, result1)
+	assert.Equal(false, result2)
+	assert.Equal(true, result3)
+	assert.Equal(false, result4)
+}
+
 func TestContainSubSlice(t *testing.T) {
 	assert := internal.NewAssert(t, "TestContainSubSlice")
 	assert.Equal(true, ContainSubSlice([]string{"a", "a", "b", "c"}, []string{"a", "a"}))
@@ -315,6 +338,36 @@ func TestMap(t *testing.T) {
 	assert.Equal(studentsOfAdd10Aage, Map(students, mapFunc))
 }

+func TestFilterMap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFilterMap")
+
+	nums := []int{1, 2, 3, 4, 5}
+
+	getEvenNumStr := func(i, num int) (string, bool) {
+		if num%2 == 0 {
+			return strconv.FormatInt(int64(num), 10), true
+		}
+		return "", false
+	}
+
+	result := FilterMap(nums, getEvenNumStr)
+
+	assert.Equal([]string{"2", "4"}, result)
+}
+
+func TestFlatMap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestFlatMap")
+
+	nums := []int{1, 2, 3, 4}
+
+	result := FlatMap(nums, func(i int, num int) []string {
+		s := "hi-" + strconv.FormatInt(int64(num), 10)
+		return []string{s}
+	})
+
+	assert.Equal([]string{"hi-1", "hi-2", "hi-3", "hi-4"}, result)
+}
+
 func TestReduce(t *testing.T) {
 	cases := [][]int{
 		{},
@@ -377,7 +430,7 @@ func TestDeleteAt(t *testing.T) {
 }

 func TestDrop(t *testing.T) {
-	assert := internal.NewAssert(t, "TestInterfaceSlice")
+	assert := internal.NewAssert(t, "TestDrop")

 	assert.Equal([]int{}, Drop([]int{}, 0))
 	assert.Equal([]int{}, Drop([]int{}, 1))
@@ -388,9 +441,64 @@ func TestDrop(t *testing.T) {
 	assert.Equal([]int{}, Drop([]int{1, 2, 3, 4, 5}, 5))
 	assert.Equal([]int{}, Drop([]int{1, 2, 3, 4, 5}, 6))

-	assert.Equal([]int{1, 2, 3, 4}, Drop([]int{1, 2, 3, 4, 5}, -1))
-	assert.Equal([]int{}, Drop([]int{1, 2, 3, 4, 5}, -6))
-	assert.Equal([]int{}, Drop([]int{1, 2, 3, 4, 5}, -6))
+	assert.Equal([]int{1, 2, 3, 4, 5}, Drop([]int{1, 2, 3, 4, 5}, -1))
+}
+
+func TestDropRight(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDropRight")
+
+	assert.Equal([]int{}, DropRight([]int{}, 0))
+	assert.Equal([]int{}, DropRight([]int{}, 1))
+	assert.Equal([]int{}, DropRight([]int{}, -1))
+
+	assert.Equal([]int{1, 2, 3, 4, 5}, DropRight([]int{1, 2, 3, 4, 5}, 0))
+	assert.Equal([]int{1, 2, 3, 4}, DropRight([]int{1, 2, 3, 4, 5}, 1))
+	assert.Equal([]int{}, DropRight([]int{1, 2, 3, 4, 5}, 5))
+	assert.Equal([]int{}, DropRight([]int{1, 2, 3, 4, 5}, 6))
+
+	assert.Equal([]int{1, 2, 3, 4, 5}, DropRight([]int{1, 2, 3, 4, 5}, -1))
+}
+
+func TestDropWhile(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDropWhile")
+
+	numbers := []int{1, 2, 3, 4, 5}
+
+	r1 := DropWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	assert.Equal([]int{2, 3, 4, 5}, r1)
+
+	r2 := DropWhile(numbers, func(n int) bool {
+		return true
+	})
+	assert.Equal([]int{}, r2)
+
+	r3 := DropWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+	assert.Equal([]int{1, 2, 3, 4, 5}, r3)
+}
+
+func TestDropRightWhile(t *testing.T) {
+	assert := internal.NewAssert(t, "TestDropRightWhile")
+
+	numbers := []int{1, 2, 3, 4, 5}
+
+	r1 := DropRightWhile(numbers, func(n int) bool {
+		return n != 2
+	})
+	assert.Equal([]int{1, 2}, r1)
+
+	r2 := DropRightWhile(numbers, func(n int) bool {
+		return true
+	})
+	assert.Equal([]int{}, r2)
+
+	r3 := DropRightWhile(numbers, func(n int) bool {
+		return n == 0
+	})
+	assert.Equal([]int{1, 2, 3, 4, 5}, r3)
 }

 func TestInsertAt(t *testing.T) {
@@ -548,6 +656,46 @@ func TestDifferenceBy(t *testing.T) {
 	assert.Equal([]int{1, 2}, DifferenceBy(s1, s2, addOne))
 }

+func TestIsAscending(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsAscending")
+
+	assert.Equal(true, IsAscending([]int{1, 2, 3, 4, 5}))
+	assert.Equal(false, IsAscending([]int{5, 4, 3, 2, 1}))
+	assert.Equal(false, IsAscending([]int{2, 1, 3, 4, 5}))
+}
+
+func TestIsDescending(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsDescending")
+
+	assert.Equal(true, IsDescending([]int{5, 4, 3, 2, 1}))
+	assert.Equal(false, IsDescending([]int{1, 2, 3, 4, 5}))
+	assert.Equal(false, IsDescending([]int{2, 1, 3, 4, 5}))
+}
+
+func TestIsSorted(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsSorted")
+
+	assert.Equal(true, IsSorted([]int{5, 4, 3, 2, 1}))
+	assert.Equal(true, IsSorted([]int{1, 2, 3, 4, 5}))
+	assert.Equal(false, IsSorted([]int{2, 1, 3, 4, 5}))
+}
+
+func TestIsSortedByKey(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsSortedByKey")
+
+	assert.Equal(true, IsSortedByKey([]string{"a", "ab", "abc"}, func(s string) int {
+		return len(s)
+	}))
+
+	assert.Equal(true, IsSortedByKey([]string{"abc", "ab", "a"}, func(s string) int {
+		return len(s)
+	}))
+
+	assert.Equal(false, IsSortedByKey([]string{"abc", "a", "ab"}, func(s string) int {
+		return len(s)
+	}))
+}
+
 func TestSort(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSort")

--- a/stream/stream.go
+++ b/stream/stream.go
@@ -10,6 +10,7 @@ import (
 	"bytes"
 	"encoding/gob"

+	"github.com/duke-git/lancet/v2/slice"
 	"golang.org/x/exp/constraints"
 )

@@ -23,7 +24,7 @@ import (
 // 	Map(mapper func(item T) T) StreamI[T]
 // 	Peek(consumer func(item T)) StreamI[T]

-// 	Sort(less func(a, b T) bool) StreamI[T]
+// 	Sorted(less func(a, b T) bool) StreamI[T]
 // 	Max(less func(a, b T) bool) (T, bool)
 // 	Min(less func(a, b T) bool) (T, bool)

@@ -43,7 +44,7 @@ import (

 // 	// part of methods custom extension
 // 	Reverse() StreamI[T]
-// 	Range(start, end int64) StreamI[T]
+// 	Range(start, end int) StreamI[T]
 // 	Concat(streams ...StreamI[T]) StreamI[T]
 // }

@@ -72,12 +73,12 @@ func Generate[T any](generator func() func() (item T, ok bool)) stream[T] {
 	return FromSlice(source)
 }

-// FromSlice create stream from slice.
+// FromSlice creates stream from slice.
 func FromSlice[T any](source []T) stream[T] {
 	return stream[T]{source: source}
 }

-// FromChannel create stream from channel.
+// FromChannel creates stream from channel.
 func FromChannel[T any](source <-chan T) stream[T] {
 	s := make([]T, 0)

@@ -88,7 +89,7 @@ func FromChannel[T any](source <-chan T) stream[T] {
 	return FromSlice(s)
 }

-// FromRange create a number stream from start to end. both start and end are included. [start, end]
+// FromRange creates a number stream from start to end. both start and end are included. [start, end]
 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")
@@ -106,6 +107,16 @@ func FromRange[T constraints.Integer | constraints.Float](start, end, step T) st
 	return FromSlice(source)
 }

+// 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.
+func Concat[T any](a, b stream[T]) stream[T] {
+	source := make([]T, 0)
+
+	source = append(source, a.source...)
+	source = append(source, b.source...)
+
+	return FromSlice(source)
+}
+
 // Distinct returns a stream that removes the duplicated items.
 func (s stream[T]) Distinct() stream[T] {
 	source := make([]T, 0)
@@ -255,6 +266,98 @@ 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.
+func (s stream[T]) FindFirst() (T, bool) {
+	var result T
+
+	if s.source == nil || len(s.source) == 0 {
+		return result, false
+	}
+
+	return s.source[0], true
+}
+
+// Reverse returns a stream whose elements are reverse order of given stream.
+func (s stream[T]) Reverse() stream[T] {
+	l := len(s.source)
+	source := make([]T, l)
+
+	for i := 0; i < l; i++ {
+		source[i] = s.source[l-1-i]
+	}
+	return FromSlice(source)
+}
+
+// Range returns a stream whose elements are in the range from start(included) to end(excluded) original stream.
+func (s stream[T]) Range(start, end int) stream[T] {
+	if start < 0 {
+		start = 0
+	}
+	if end < 0 {
+		end = 0
+	}
+	if start >= end {
+		return FromSlice([]T{})
+	}
+
+	source := make([]T, 0)
+
+	if end > len(s.source) {
+		end = len(s.source)
+	}
+
+	for i := start; i < end; i++ {
+		source = append(source, s.source[i])
+	}
+
+	return FromSlice(source)
+}
+
+// Sorted returns a stream consisting of the elements of this stream, sorted according to the provided less function.
+func (s stream[T]) Sorted(less func(a, b T) bool) stream[T] {
+	source := []T{}
+	source = append(source, s.source...)
+
+	slice.SortBy(source, less)
+
+	return FromSlice(source)
+}
+
+// Max returns the maximum element of this stream according to the provided less function.
+// less: a > b
+func (s stream[T]) Max(less func(a, b T) bool) (T, bool) {
+	var max T
+
+	if len(s.source) == 0 {
+		return max, false
+	}
+
+	for i, v := range s.source {
+		if less(v, max) || i == 0 {
+			max = v
+		}
+	}
+	return max, true
+}
+
+// Min returns the minimum element of this stream according to the provided less function.
+// less: a < b
+func (s stream[T]) Min(less func(a, b T) bool) (T, bool) {
+	var min T
+
+	if len(s.source) == 0 {
+		return min, false
+	}
+
+	for i, v := range s.source {
+		if less(v, min) || i == 0 {
+			min = v
+		}
+	}
+
+	return min, true
+}
+
 // ToSlice return the elements in the stream.
 func (s stream[T]) ToSlice() []T {
 	return s.source
--- a/stream/stream_test.go
+++ b/stream/stream_test.go
@@ -247,3 +247,92 @@ func TestStream_Reduce(t *testing.T) {

 	assert.Equal(6, result)
 }
+
+func TestStream_FindFirst(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_FindFirst")
+
+	stream := FromSlice([]int{1, 2, 3})
+
+	result, ok := stream.FindFirst()
+
+	assert.Equal(1, result)
+	assert.Equal(true, ok)
+}
+
+func TestStream_Reverse(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Reverse")
+
+	s := FromSlice([]int{1, 2, 3})
+
+	rs := s.Reverse()
+
+	assert.Equal([]int{3, 2, 1}, rs.ToSlice())
+}
+
+func TestStream_Range(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Range")
+
+	s := FromSlice([]int{1, 2, 3})
+
+	s1 := s.Range(-1, 0)
+	assert.Equal([]int{}, s1.ToSlice())
+
+	s2 := s.Range(0, -1)
+	assert.Equal([]int{}, s2.ToSlice())
+
+	s3 := s.Range(0, 0)
+	assert.Equal([]int{}, s3.ToSlice())
+
+	s4 := s.Range(1, 1)
+	assert.Equal([]int{}, s4.ToSlice())
+
+	s5 := s.Range(0, 1)
+	assert.Equal([]int{1}, s5.ToSlice())
+
+	s6 := s.Range(0, 4)
+	assert.Equal([]int{1, 2, 3}, s6.ToSlice())
+}
+
+func TestStream_Concat(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Concat")
+
+	s1 := FromSlice([]int{1, 2, 3})
+	s2 := FromSlice([]int{4, 5, 6})
+
+	s := Concat(s1, s2)
+
+	assert.Equal([]int{1, 2, 3, 4, 5, 6}, s.ToSlice())
+}
+
+func TestStream_Sorted(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Sorted")
+
+	s := FromSlice([]int{4, 2, 1, 3})
+
+	s1 := s.Sorted(func(a, b int) bool { return a < b })
+
+	assert.Equal([]int{4, 2, 1, 3}, s.ToSlice())
+	assert.Equal([]int{1, 2, 3, 4}, s1.ToSlice())
+}
+
+func TestStream_Max(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Max")
+
+	s := FromSlice([]int{4, 2, 1, 3})
+
+	max, ok := s.Max(func(a, b int) bool { return a > b })
+
+	assert.Equal(4, max)
+	assert.Equal(true, ok)
+}
+
+func TestStream_Min(t *testing.T) {
+	assert := internal.NewAssert(t, "TestStream_Min")
+
+	s := FromSlice([]int{4, 2, 1, 3})
+
+	max, ok := s.Max(func(a, b int) bool { return a < b })
+
+	assert.Equal(1, max)
+	assert.Equal(true, ok)
+}
--- a/strutil/string.go
+++ b/strutil/string.go
@@ -67,44 +67,25 @@ func LowerFirst(s string) string {
 	return string(r) + s[size:]
 }

-// PadEnd pads string on the right side if it's shorter than size.
+// PadStart pads string on the left and right side if it's shorter than size.
 // Padding characters are truncated if they exceed size.
-// Play: https://go.dev/play/p/9xP8rN0vz--
-func PadEnd(source string, size int, padStr string) string {
-	len1 := len(source)
-	len2 := len(padStr)
-
-	if len1 >= size {
-		return source
-	}
-
-	fill := ""
-	if len2 >= size-len1 {
-		fill = padStr[0 : size-len1]
-	} else {
-		fill = strings.Repeat(padStr, size-len1)
-	}
-	return source + fill[0:size-len1]
+// Play: todo
+func Pad(source string, size int, padStr string) string {
+	return padAtPosition(source, size, padStr, 0)
 }

 // PadStart pads string on the left side if it's shorter than size.
 // Padding characters are truncated if they exceed size.
 // Play: https://go.dev/play/p/xpTfzArDfvT
 func PadStart(source string, size int, padStr string) string {
-	len1 := len(source)
-	len2 := len(padStr)
+	return padAtPosition(source, size, padStr, 1)
+}

-	if len1 >= size {
-		return source
-	}
-
-	fill := ""
-	if len2 >= size-len1 {
-		fill = padStr[0 : size-len1]
-	} else {
-		fill = strings.Repeat(padStr, size-len1)
-	}
-	return fill[0:size-len1] + source
+// PadEnd pads string on the right side if it's shorter than size.
+// Padding characters are truncated if they exceed size.
+// Play: https://go.dev/play/p/9xP8rN0vz--
+func PadEnd(source string, size int, padStr string) string {
+	return padAtPosition(source, size, padStr, 2)
 }

 // KebabCase coverts string to kebab-case, non letters and numbers will be ignored.
@@ -306,3 +287,76 @@ func Substring(s string, offset int, length uint) string {

 	return strings.Replace(str, "\x00", "", -1)
 }
+
+// SplitWords splits a string into words, word only contains alphabetic characters.
+// Play: todo
+func SplitWords(s string) []string {
+	var word string
+	var words []string
+	var r rune
+	var size, pos int
+
+	isWord := false
+
+	for len(s) > 0 {
+		r, size = utf8.DecodeRuneInString(s)
+
+		switch {
+		case isLetter(r):
+			if !isWord {
+				isWord = true
+				word = s
+				pos = 0
+			}
+
+		case isWord && (r == '\'' || r == '-'):
+			// is word
+
+		default:
+			if isWord {
+				isWord = false
+				words = append(words, word[:pos])
+			}
+		}
+
+		pos += size
+		s = s[size:]
+	}
+
+	if isWord {
+		words = append(words, word[:pos])
+	}
+
+	return words
+}
+
+// WordCount return the number of meaningful word, word only contains alphabetic characters.
+// Play: todo
+func WordCount(s string) int {
+	var r rune
+	var size, count int
+
+	isWord := false
+
+	for len(s) > 0 {
+		r, size = utf8.DecodeRuneInString(s)
+
+		switch {
+		case isLetter(r):
+			if !isWord {
+				isWord = true
+				count++
+			}
+
+		case isWord && (r == '\'' || r == '-'):
+			// is word
+
+		default:
+			isWord = false
+		}
+
+		s = s[size:]
+	}
+
+	return count
+}
--- a/strutil/string_example_test.go
+++ b/strutil/string_example_test.go
@@ -186,6 +186,33 @@ func ExampleUpperFirst() {
 	// Bar大
 }

+func ExamplePad() {
+	result1 := Pad("foo", 1, "bar")
+	result2 := Pad("foo", 2, "bar")
+	result3 := Pad("foo", 3, "bar")
+	result4 := Pad("foo", 4, "bar")
+	result5 := Pad("foo", 5, "bar")
+	result6 := Pad("foo", 6, "bar")
+	result7 := Pad("foo", 7, "bar")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+	fmt.Println(result6)
+	fmt.Println(result7)
+
+	// Output:
+	// foo
+	// foo
+	// foo
+	// foob
+	// bfoob
+	// bfooba
+	// bafooba
+}
+
 func ExamplePadEnd() {
 	result1 := PadEnd("foo", 1, "bar")
 	result2 := PadEnd("foo", 2, "bar")
@@ -361,3 +388,53 @@ func ExampleSubstring() {
 	// de
 	// 你好
 }
+
+func ExampleSplitWords() {
+
+	result1 := SplitWords("a word")
+	result2 := SplitWords("I'am a programmer")
+	result3 := SplitWords("Bonjour, je suis programmeur")
+	result4 := SplitWords("a -b-c' 'd'e")
+	result5 := SplitWords("你好，我是一名码农")
+	result6 := SplitWords("こんにちは，私はプログラマーです")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+	fmt.Println(result6)
+
+	// Output:
+	// [a word]
+	// [I'am a programmer]
+	// [Bonjour je suis programmeur]
+	// [a b-c' d'e]
+	// []
+	// []
+}
+
+func ExampleWordCount() {
+
+	result1 := WordCount("a word")
+	result2 := WordCount("I'am a programmer")
+	result3 := WordCount("Bonjour, je suis programmeur")
+	result4 := WordCount("a -b-c' 'd'e")
+	result5 := WordCount("你好，我是一名码农")
+	result6 := WordCount("こんにちは，私はプログラマーです")
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+	fmt.Println(result5)
+	fmt.Println(result6)
+
+	// Output:
+	// 2
+	// 3
+	// 4
+	// 3
+	// 0
+	// 0
+}
--- a/strutil/string_internal.go
+++ b/strutil/string_internal.go
@@ -98,3 +98,73 @@ func toUpperAll(rs []rune) []rune {
 	}
 	return rs
 }
+
+// padWithPosition pads string
+func padAtPosition(str string, length int, padStr string, position int) string {
+	if len(str) >= length {
+		return str
+	}
+
+	if padStr == "" {
+		padStr = " "
+	}
+
+	length = length - len(str)
+	startPadLen := 0
+	if position == 0 {
+		startPadLen = length / 2
+	} else if position == 1 {
+		startPadLen = length
+	}
+	endPadLen := length - startPadLen
+
+	charLen := len(padStr)
+	leftPad := ""
+	cur := 0
+	for cur < startPadLen {
+		leftPad += string(padStr[cur%charLen])
+		cur++
+	}
+
+	cur = 0
+	rightPad := ""
+	for cur < endPadLen {
+		rightPad += string(padStr[cur%charLen])
+		cur++
+	}
+
+	return leftPad + str + rightPad
+}
+
+// isLetter checks r is a letter but not CJK character.
+func isLetter(r rune) bool {
+	if !unicode.IsLetter(r) {
+		return false
+	}
+
+	switch {
+	// cjk char: /[\u3040-\u30ff\u3400-\u4dbf\u4e00-\u9fff\uf900-\ufaff\uff66-\uff9f]/
+
+	// hiragana and katakana (Japanese only)
+	case r >= '\u3034' && r < '\u30ff':
+		return false
+
+	// CJK unified ideographs extension A (Chinese, Japanese, and Korean)
+	case r >= '\u3400' && r < '\u4dbf':
+		return false
+
+	// CJK unified ideographs (Chinese, Japanese, and Korean)
+	case r >= '\u4e00' && r < '\u9fff':
+		return false
+
+	// CJK compatibility ideographs (Chinese, Japanese, and Korean)
+	case r >= '\uf900' && r < '\ufaff':
+		return false
+
+	// half-width katakana (Japanese only)
+	case r >= '\uff66' && r < '\uff9f':
+		return false
+	}
+
+	return true
+}
--- a/strutil/string_test.go
+++ b/strutil/string_test.go
@@ -168,9 +168,19 @@ func TestLowerFirst(t *testing.T) {
 	}
 }

+func TestPad(t *testing.T) {
+	assert := internal.NewAssert(t, "TestPad")
+
+	assert.Equal("a ", Pad("a", 2, ""))
+	assert.Equal("a", Pad("a", 1, "b"))
+	assert.Equal("ab", Pad("a", 2, "b"))
+	assert.Equal("mabcdm", Pad("abcd", 6, "m"))
+}
+
 func TestPadEnd(t *testing.T) {
 	assert := internal.NewAssert(t, "TestPadEnd")

+	assert.Equal("a ", PadEnd("a", 2, " "))
 	assert.Equal("a", PadEnd("a", 1, "b"))
 	assert.Equal("ab", PadEnd("a", 2, "b"))
 	assert.Equal("abcdmn", PadEnd("abcd", 6, "mno"))
@@ -298,3 +308,37 @@ func TestSubstring(t *testing.T) {
 	assert.Equal("de", Substring("abcde", -2, 3))
 	assert.Equal("你好", Substring("你好，欢迎你", 0, 2))
 }
+
+func TestSplitWords(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSplitWords")
+
+	cases := map[string][]string{
+		"a word":                       {"a", "word"},
+		"I'am a programmer":            {"I'am", "a", "programmer"},
+		"Bonjour, je suis programmeur": {"Bonjour", "je", "suis", "programmeur"},
+		"a -b-c' 'd'e":                 {"a", "b-c'", "d'e"},
+		"你好，我是一名码农":                    nil,
+		"こんにちは，私はプログラマーです": nil,
+	}
+
+	for k, v := range cases {
+		assert.Equal(v, SplitWords(k))
+	}
+}
+
+func TestWordCount(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSplitWords")
+
+	cases := map[string]int{
+		"a word":                       2, //   {"a", "word"},
+		"I'am a programmer":            3, //   {"I'am", "a", "programmer"},
+		"Bonjour, je suis programmeur": 4, // {"Bonjour", "je", "suis", "programmeur"},
+		"a -b-c' 'd'e":                 3, // {"a", "b-c'", "d'e"},
+		"你好，我是一名码农":                    0, // nil,
+		"こんにちは，私はプログラマーです": 0, // nil,
+	}
+
+	for k, v := range cases {
+		assert.Equal(v, WordCount(k))
+	}
+}
--- a/validator/validator.go
+++ b/validator/validator.go
@@ -281,6 +281,10 @@ func IsZeroValue(value any) bool {
 	}

 	rv := reflect.ValueOf(value)
+	if rv.Kind() == reflect.Ptr {
+		rv = rv.Elem()
+	}
+
 	if !rv.IsValid() {
 		return true
 	}
--- a/xerror/stack.go
+++ b/xerror/stack.go
@@ -0,0 +1,228 @@
+// Copyright 2023 dudaodong@gmail.com. All rights reserved.
+// Use of this source code is governed by MIT license
+
+package xerror
+
+import (
+	"fmt"
+	"io"
+	"path"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+// Stack contains function, file and line number info in the stack trace.
+type Stack struct {
+	Func string `json:"func"`
+	File string `json:"file"`
+	Line int    `json:"line"`
+}
+
+// Stacks returns stack trace array generated by pkg/errors
+func (e *XError) Stacks() []*Stack {
+	resp := make([]*Stack, len(*e.stack))
+	for i, st := range *e.stack {
+		f := frame(st)
+		resp[i] = &Stack{
+			Func: f.name(),
+			File: f.file(),
+			Line: f.line(),
+		}
+	}
+	return resp
+}
+
+// StackTrace returns stack trace which is compatible with pkg/errors
+func (e *XError) StackTrace() StackTrace {
+	return e.stack.StackTrace()
+}
+
+// ---------------------------------------
+// Stacktrace part is implemented based on copy of https://github.com/pkg/errors
+//
+// Copyright (c) 2015, Dave Cheney <dave@cheney.net>
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// * Redistributions of source code must retain the above copyright notice, this
+//   list of conditions and the following disclaimer.
+//
+// * Redistributions in binary form must reproduce the above copyright notice,
+//   this list of conditions and the following disclaimer in the documentation
+//   and/or other materials provided with the distribution.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+type frame uintptr
+type stack []uintptr
+
+// StackTrace is array of frame. It's exported for compatibility with github.com/pkg/errors
+type StackTrace []frame
+
+// pc returns the program counter for this frame;
+// multiple frames may have the same PC value.
+func (f frame) pc() uintptr { return uintptr(f) - 1 }
+
+// file returns the full path to the file that contains the
+// function for this Frame's pc.
+func (f frame) file() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	file, _ := fn.FileLine(f.pc())
+	return file
+}
+
+// line returns the line number of source code of the
+// function for this Frame's pc.
+func (f frame) line() int {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return 0
+	}
+	_, line := fn.FileLine(f.pc())
+	return line
+}
+
+// name returns the name of this function, if known.
+func (f frame) name() string {
+	fn := runtime.FuncForPC(f.pc())
+	if fn == nil {
+		return "unknown"
+	}
+	return fn.Name()
+}
+
+// Format of frame formats the frame according to the fmt.Formatter interface.
+//
+//	%s    source file
+//	%d    source line
+//	%n    function name
+//	%v    equivalent to %s:%d
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//	%+s   function name and path of source file relative to the compile time
+//	      GOPATH separated by \n\t (<funcname>\n\t<path>)
+//	%+v   equivalent to %+s:%d
+func (f frame) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 's':
+		switch {
+		case s.Flag('+'):
+			_, _ = io.WriteString(s, f.name())
+			_, _ = io.WriteString(s, "\n\t")
+			_, _ = io.WriteString(s, f.file())
+		default:
+			_, _ = io.WriteString(s, path.Base(f.file()))
+		}
+	case 'd':
+		_, _ = io.WriteString(s, strconv.Itoa(f.line()))
+	case 'n':
+		_, _ = io.WriteString(s, funcname(f.name()))
+	case 'v':
+		f.Format(s, 's')
+		_, _ = io.WriteString(s, ":")
+		f.Format(s, 'd')
+	}
+}
+
+// MarshalText formats a stacktrace Frame as a text string. The output is the
+// same as that of fmt.Sprintf("%+v", f), but without newlines or tabs.
+func (f frame) MarshalText() ([]byte, error) {
+	name := f.name()
+	if name == "unknown" {
+		return []byte(name), nil
+	}
+	return []byte(fmt.Sprintf("%s %s:%d", name, f.file(), f.line())), nil
+}
+
+// Format formats the stack of Frames according to the fmt.Formatter interface.
+//
+//	%s	lists source files for each Frame in the stack
+//	%v	lists the source file and line number for each Frame in the stack
+//
+// Format accepts flags that alter the printing of some verbs, as follows:
+//
+//	%+v   Prints filename, function, and line number for each Frame in the stack.
+func (st StackTrace) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case s.Flag('+'):
+			for _, f := range st {
+				_, _ = io.WriteString(s, "\n")
+				f.Format(s, verb)
+			}
+		case s.Flag('#'):
+			fmt.Fprintf(s, "%#v", []frame(st))
+		default:
+			st.formatSlice(s, verb)
+		}
+	case 's':
+		st.formatSlice(s, verb)
+	}
+}
+
+// formatSlice will format this StackTrace into the given buffer as a slice of
+// Frame, only valid when called with '%s' or '%v'.
+func (st StackTrace) formatSlice(s fmt.State, verb rune) {
+	_, _ = io.WriteString(s, "[")
+	for i, f := range st {
+		if i > 0 {
+			_, _ = io.WriteString(s, " ")
+		}
+		f.Format(s, verb)
+	}
+	_, _ = io.WriteString(s, "]")
+}
+
+func (s *stack) Format(st fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		switch {
+		case st.Flag('+'):
+			for _, pc := range *s {
+				f := frame(pc)
+				fmt.Fprintf(st, "\n%+v", f)
+			}
+		}
+	}
+}
+
+func (s *stack) StackTrace() StackTrace {
+	frames := make([]frame, len(*s))
+	for i := 0; i < len(frames); i++ {
+		frames[i] = frame((*s)[i])
+	}
+	return frames
+}
+
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(4, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// funcname removes the path prefix component of a function's name reported by func.Name().
+func funcname(name string) string {
+	i := strings.LastIndex(name, "/")
+	name = name[i+1:]
+	i = strings.Index(name, ".")
+	return name[i+1:]
+}
--- a/xerror/xerror.go
+++ b/xerror/xerror.go
@@ -4,10 +4,202 @@
 // Package xerror implements helpers for errors
 package xerror

-// Unwrap if err is nil then it returns a valid value
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/duke-git/lancet/v2/random"
+)
+
+// XError is to handle error related information.
+type XError struct {
+	id      string
+	message string
+	stack   *stack
+	cause   error
+	values  map[string]any
+}
+
+// New creates a new XError with message
+func New(format string, args ...any) *XError {
+	err := newXError()
+	err.message = fmt.Sprintf(format, args...)
+	return err
+}
+
+// Wrap creates a new XError and add message.
+func Wrap(cause error, message ...any) *XError {
+	err := newXError()
+
+	if len(message) > 0 {
+		var newMsgs []string
+		for _, m := range message {
+			newMsgs = append(newMsgs, fmt.Sprintf("%v", m))
+		}
+		err.message = strings.Join(newMsgs, " ")
+	}
+
+	err.cause = cause
+
+	return err
+}
+
+// Unwrap returns unwrapped XError from err by errors.As. If no XError, returns nil
+func Unwrap(err error) *XError {
+	var e *XError
+	if errors.As(err, &e) {
+		return e
+	}
+	return nil
+}
+
+func newXError() *XError {
+	id, err := random.UUIdV4()
+	if err != nil {
+		return nil
+	}
+
+	return &XError{
+		id:     id,
+		stack:  callers(),
+		values: make(map[string]any),
+	}
+}
+
+func (e *XError) copy(dest *XError) {
+	dest.message = e.message
+	dest.id = e.id
+	dest.cause = e.cause
+
+	for k, v := range e.values {
+		dest.values[k] = v
+	}
+}
+
+// Error implements standard error interface.
+func (e *XError) Error() string {
+	msg := e.message
+	cause := e.cause
+
+	if cause == nil {
+		return msg
+	}
+
+	msg = fmt.Sprintf("%s: %v", msg, cause.Error())
+
+	return msg
+}
+
+// Format returns:
+// - %v, %s, %q: formatted message
+// - %+v: formatted message with stack trace
+func (e *XError) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			_, _ = io.WriteString(s, e.Error())
+			e.stack.Format(s, verb)
+			return
+		}
+		fallthrough
+	case 's':
+		_, _ = io.WriteString(s, e.Error())
+	case 'q':
+		fmt.Fprintf(s, "%q", e.Error())
+	}
+}
+
+// Wrap creates a new XError and copy message and id to new one.
+func (e *XError) Wrap(cause error) *XError {
+	err := newXError()
+	e.copy(err)
+	err.cause = cause
+	return err
+}
+
+// Unwrap compatible with github.com/pkg/errors
+func (e *XError) Unwrap() error {
+	return e.cause
+}
+
+// With adds key and value related to the error object
+func (e *XError) With(key string, value any) *XError {
+	e.values[key] = value
+	return e
+}
+
+// Is checks if target error is XError and Error.id of two errors are matched.
+func (e *XError) Is(target error) bool {
+	var err *XError
+
+	if errors.As(target, &err) {
+		if e.id != "" && e.id == err.id {
+			return true
+		}
+	}
+
+	return e == target
+}
+
+// Id sets id to check equality in XError.Is
+func (e *XError) Id(id string) *XError {
+	e.id = id
+	return e
+}
+
+// Values returns map of key and value that is set by With. All wrapped xerror.XError key and values will be merged.
+// Key and values of wrapped error is overwritten by upper xerror.XError.
+func (e *XError) Values() map[string]any {
+	var values map[string]any
+
+	if cause := e.Unwrap(); cause != nil {
+		if err, ok := cause.(*XError); ok {
+			values = err.Values()
+		}
+	}
+
+	if values == nil {
+		values = make(map[string]any)
+	}
+
+	for key, value := range e.values {
+		values[key] = value
+	}
+
+	return values
+}
+
+type errInfo struct {
+	Message    string         `json:"message"`
+	Id         string         `json:"id"`
+	StackTrace []*Stack       `json:"stacktrace"`
+	Cause      error          `json:"cause"`
+	Values     map[string]any `json:"values"`
+}
+
+// Info returns information of xerror, which can be printed.
+func (e *XError) Info() *errInfo {
+	errInfo := &errInfo{
+		Message:    e.message,
+		Id:         e.id,
+		StackTrace: e.Stacks(),
+		Cause:      e.cause,
+		Values:     make(map[string]any),
+	}
+
+	for k, v := range e.values {
+		errInfo.Values[k] = v
+	}
+
+	return errInfo
+}
+
+// TryUnwrap if err is nil then it returns a valid value
 // If err is not nil, Unwrap panics with err.
 // Play: https://go.dev/play/p/w84d7Mb3Afk
-func Unwrap[T any](val T, err error) T {
+func TryUnwrap[T any](val T, err error) T {
 	if err != nil {
 		panic(err)
 	}
--- a/xerror/xerror_example_test.go
+++ b/xerror/xerror_example_test.go
@@ -1,13 +1,144 @@
 package xerror

 import (
+	"errors"
 	"fmt"
 	"reflect"
 	"strconv"
+	"strings"
 )

-func ExampleUnwrap() {
-	result1 := Unwrap(strconv.Atoi("42"))
+func ExampleNew() {
+	err := New("error")
+	fmt.Println(err.Error())
+
+	// Output:
+	// error
+}
+
+func ExampleWrap() {
+	err := New("wrong password")
+	wrapErr := Wrap(err, "error")
+
+	fmt.Println(wrapErr.Error())
+
+	// Output:
+	// error: wrong password
+}
+
+func ExampleXError_Wrap() {
+	err1 := New("error").With("level", "high")
+	err2 := err1.Wrap(errors.New("invalid username"))
+
+	fmt.Println(err2.Error())
+
+	// Output:
+	// error: invalid username
+}
+
+func ExampleXError_Unwrap() {
+	err1 := New("error").With("level", "high")
+	err2 := err1.Wrap(errors.New("invalid username"))
+
+	err := err2.Unwrap()
+
+	fmt.Println(err.Error())
+
+	// Output:
+	// invalid username
+}
+
+func ExampleXError_StackTrace() {
+	err := New("error")
+
+	stacks := err.Stacks()
+
+	fmt.Println(stacks[0].Func)
+	fmt.Println(stacks[0].Line)
+
+	containFile := strings.Contains(stacks[0].File, "xerror_example_test.go")
+	fmt.Println(containFile)
+
+	// Output:
+	// github.com/duke-git/lancet/v2/xerror.ExampleXError_StackTrace
+	// 52
+	// true
+}
+
+func ExampleXError_With() {
+	err := New("error").With("level", "high")
+
+	errLevel := err.Values()["level"]
+
+	fmt.Println(errLevel)
+
+	// Output:
+	// high
+}
+
+func ExampleXError_Id() {
+	err1 := New("error").Id("e001")
+	err2 := New("error").Id("e001")
+	err3 := New("error").Id("e003")
+
+	equal := err1.Is(err2)
+	notEqual := err1.Is(err3)
+
+	fmt.Println(equal)
+	fmt.Println(notEqual)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleXError_Is() {
+	err1 := New("error").Id("e001")
+	err2 := New("error").Id("e001")
+	err3 := New("error").Id("e003")
+
+	equal := err1.Is(err2)
+	notEqual := err1.Is(err3)
+
+	fmt.Println(equal)
+	fmt.Println(notEqual)
+
+	// Output:
+	// true
+	// false
+}
+
+func ExampleXError_Values() {
+	err := New("error").With("level", "high")
+
+	errLevel := err.Values()["level"]
+
+	fmt.Println(errLevel)
+
+	// Output:
+	// high
+}
+
+func ExampleXError_Info() {
+	cause := errors.New("error")
+	err := Wrap(cause, "invalid username").Id("e001").With("level", "high")
+
+	errInfo := err.Info()
+
+	fmt.Println(errInfo.Id)
+	fmt.Println(errInfo.Cause)
+	fmt.Println(errInfo.Values["level"])
+	fmt.Println(errInfo.Message)
+
+	// Output:
+	// e001
+	// error
+	// high
+	// invalid username
+}
+
+func ExampleTryUnwrap() {
+	result1 := TryUnwrap(strconv.Atoi("42"))
 	fmt.Println(result1)

 	_, err := strconv.Atoi("4o2")
@@ -17,7 +148,7 @@ func ExampleUnwrap() {
 		fmt.Println(result2)
 	}()

-	Unwrap(strconv.Atoi("4o2"))
+	TryUnwrap(strconv.Atoi("4o2"))

 	// Output:
 	// 42
--- a/xerror/xerror_test.go
+++ b/xerror/xerror_test.go
@@ -1,19 +1,21 @@
 package xerror

 import (
+	"errors"
 	"strconv"
+	"strings"
 	"testing"

 	"github.com/duke-git/lancet/v2/internal"
 )

-func TestUnwrap(t *testing.T) {
-	assert := internal.NewAssert(t, "TestUnwrap")
-	assert.Equal(42, Unwrap(strconv.Atoi("42")))
+func TestTryUnwrap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestTryUnwrap")
+	assert.Equal(42, TryUnwrap(strconv.Atoi("42")))
 }

-func TestUnwrapFail(t *testing.T) {
-	assert := internal.NewAssert(t, "TestUnwrapFail")
+func TestTryUnwrapFail(t *testing.T) {
+	assert := internal.NewAssert(t, "TestTryUnwrapFail")

 	_, err := strconv.Atoi("4o2")
 	defer func() {
@@ -21,5 +23,85 @@ func TestUnwrapFail(t *testing.T) {
 		assert.Equal(err.Error(), v.(*strconv.NumError).Error())
 	}()

-	Unwrap(strconv.Atoi("4o2"))
+	TryUnwrap(strconv.Atoi("4o2"))
+}
+
+func TestNew(t *testing.T) {
+	assert := internal.NewAssert(t, "TestNew")
+
+	err := New("error occurs")
+	assert.Equal("error occurs", err.Error())
+}
+
+func TestWrap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestWrap")
+
+	err := New("wrong password")
+	wrapErr := Wrap(err, "error")
+
+	assert.Equal("error: wrong password", wrapErr.Error())
+}
+
+func TestXError_Wrap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestXError_Wrap")
+
+	err1 := New("error").With("level", "high")
+	err2 := err1.Wrap(errors.New("bad"))
+
+	assert.Equal("error: bad", err2.Error())
+}
+
+func TestXError_Unwrap(t *testing.T) {
+	assert := internal.NewAssert(t, "TestXError_Unwrap")
+
+	err1 := New("error").With("level", "high")
+
+	err2 := err1.Wrap(errors.New("bad"))
+
+	err := err2.Unwrap()
+
+	assert.Equal("bad", err.Error())
+}
+
+func TestXError_StackTrace(t *testing.T) {
+	assert := internal.NewAssert(t, "TestXError_StackTrace")
+
+	err := New("error")
+
+	stacks := err.Stacks()
+
+	assert.Equal(3, len(stacks))
+	assert.Equal("github.com/duke-git/lancet/v2/xerror.TestXError_StackTrace", stacks[0].Func)
+	assert.Equal(69, stacks[0].Line)
+	assert.Equal(true, strings.Contains(stacks[0].File, "xerror_test.go"))
+}
+
+func TestXError_With_Id_Is_Values(t *testing.T) {
+	assert := internal.NewAssert(t, "TestXError_With_Id_Is_Values")
+
+	baseErr := New("baseError")
+	err1 := New("error1").Id("e001").With("level", "high")
+	err2 := New("error2").Id("e002").With("level", "low")
+
+	err := err1.Wrap(baseErr).With("v", "1.0")
+
+	assert.Equal(true, errors.Is(err, baseErr))
+	assert.NotEqual(err, err1)
+	assert.IsNotNil(err.Values()["v"])
+	assert.IsNil(err1.Values()["v"])
+
+	assert.Equal(false, errors.Is(err, err2))
+}
+
+func TestXError_Info(t *testing.T) {
+	assert := internal.NewAssert(t, "TestXError_Info")
+
+	cause := errors.New("error")
+	err := Wrap(cause, "invalid username").Id("e001").With("level", "high")
+
+	errInfo := err.Info()
+	assert.Equal("invalid username", errInfo.Message)
+	assert.Equal("e001", errInfo.Id)
+	assert.Equal(cause, errInfo.Cause)
+	assert.Equal("high", errInfo.Values["level"])
 }
Author	SHA1	Message	Date
dudaodong	66efe61834	release v2.1.16	2023-03-01 10:08:53 +08:00
dudaodong	94f7f3e0e5	doc: add new function docs	2023-02-28 15:03:02 +08:00
dudaodong	9d2c9806d1	feat: add ContainBy function	2023-02-24 14:19:10 +08:00
dudaodong	e523d4af6e	doc: add doc for FilterMap and FlatMap	2023-02-24 11:23:02 +08:00
dudaodong	f3801bcd8f	feat: add FlatMap	2023-02-24 11:14:59 +08:00
dudaodong	5767aad303	feat: add FilterMap	2023-02-24 10:55:27 +08:00
dudaodong	f7aaa1ed2a	fix: fix issue #75	2023-02-23 11:43:41 +08:00
dudaodong	ef19a414bc	doc: fix doc error	2023-02-23 10:58:43 +08:00
dudaodong	65704dea06	doc: fix doc error	2023-02-23 10:57:48 +08:00
dudaodong	5eac358bb0	doc: format code in doc file	2023-02-22 17:00:46 +08:00
dudaodong	8e36ef5cef	doc: add doc for new map functions	2023-02-22 16:59:01 +08:00
dudaodong	21b0d2ec0e	doc: add doc for WordCount and SplitWords function	2023-02-22 16:13:41 +08:00
dudaodong	32ca975204	feat: add OmitBy, OmitByKeys, OmitByValues	2023-02-21 14:52:10 +08:00
dudaodong	ec740e442c	feat: add WordCount	2023-02-21 14:27:00 +08:00
dudaodong	ed98ad53ec	feat: add SplitWords	2023-02-21 14:16:36 +08:00
dudaodong	af7b9d2710	doc: add doc for CopyProperties function	2023-02-20 14:10:55 +08:00
dudaodong	f08b368001	fix: update param type of CopyProperties	2023-02-20 14:04:45 +08:00
dudaodong	be8a0558f8	test: add examples for CopyProperties function	2023-02-20 12:00:49 +08:00
dudaodong	46de539e22	feat: add CopyProperties for merge properties between structs	2023-02-20 11:48:30 +08:00
dudaodong	36fb3abe9e	test: add examples for maputil package function	2023-02-19 16:59:21 +08:00
dudaodong	fee8d325b7	doc: add doc for Pad function	2023-02-19 12:58:14 +08:00
dudaodong	8784be1583	feat: add Pad function	2023-02-19 12:37:26 +08:00
dudaodong	84cd68de7f	fix: fix bugs of PadEnd and PadStart	2023-02-19 12:34:39 +08:00
dudaodong	a774c060ce	feat: add MapKeys and MapValues	2023-02-17 15:41:58 +08:00
dudaodong	730f061b95	feat: add Entries FromEntries Transform	2023-02-17 15:24:46 +08:00
dudaodong	2eb08f3404	feat: add FilterByValues function	2023-02-17 11:59:44 +08:00
dudaodong	4c1496b648	feat: add FilterByKeys function	2023-02-17 11:57:09 +08:00
dudaodong	c2ae784f27	feat: add ValuesBy function	2023-02-17 11:48:11 +08:00
dudaodong	e71cecefea	feat: add KeysBy function	2023-02-17 11:40:20 +08:00
dudaodong	572e53aa14	doc: add go playground demo for xerror package	2023-02-16 14:28:50 +08:00
dudaodong	ca9ecb9c8a	update go playground demo	2023-02-16 14:10:24 +08:00
dudaodong	8bf0786abe	release v2.1.15	2023-02-16 12:02:34 +08:00
dudaodong	61cb8395e3	doc: update doc for xerror package	2023-02-15 14:41:56 +08:00
dudaodong	dde8a41daf	doc: update doc for xerror package	2023-02-15 14:41:41 +08:00
dudaodong	d7518e01af	doc: fix ExampleXError_StackTrace bug	2023-02-15 12:04:14 +08:00
dudaodong	be9fa7acaa	doc: update doc for xerror package	2023-02-15 11:58:33 +08:00
dudaodong	2629a731cc	doc: update doc for xerror package	2023-02-15 11:53:21 +08:00
dudaodong	54c7f90b7f	test: add examples for xerror package	2023-02-15 10:39:51 +08:00
dudaodong	770bc88b88	doc: update doc for xerror package	2023-02-15 10:14:26 +08:00
dudaodong	4cc1722f81	feat: fix AesEcbEncrypt and AesEcbDecrypt	2023-02-14 16:42:25 +08:00
dudaodong	d0260b2841	feat: add XError to support more contextual error handling	2023-02-14 16:32:57 +08:00
dudaodong	57bd64cae7	feat: add stack	2023-02-14 10:21:38 +08:00
dudaodong	c383719496	doc: add doc for DeepClone function	2023-02-12 19:24:56 +08:00
dudaodong	4b196a72b1	feat: add DeepClone	2023-02-10 15:50:28 +08:00
dudaodong	888381a06c	doc: add drop and sort related function doc	2023-02-10 10:53:41 +08:00
dudaodong	a554eb7ef4	doc: add doc for sort function	2023-02-10 10:42:38 +08:00
dudaodong	26ff90122b	doc: add doc for Drop function	2023-02-10 10:31:02 +08:00
dudaodong	75b27c6540	feat: add IsSortedByKey	2023-02-10 10:10:57 +08:00
dudaodong	a7e77fa98d	feat: add IsSorted	2023-02-09 19:30:11 +08:00
dudaodong	abf392117a	feat: add IsAscending, Isdescending	2023-02-09 19:25:58 +08:00
dudaodong	d231d9f572	feat: add DropRightWhile	2023-02-09 17:53:26 +08:00
dudaodong	97447d058e	test: add test and example for DropWhile	2023-02-09 17:46:40 +08:00
dudaodong	040e112aa6	feat: add DropRight and DropWhile	2023-02-09 17:38:31 +08:00
dudaodong	afb021b4b5	feat: add Max, Min for stream	2023-02-08 15:20:29 +08:00
dudaodong	5075774000	feat: add Sorted for stream	2023-02-08 15:07:09 +08:00
dudaodong	6bba44dc50	feat: add Concat for stream	2023-02-07 10:47:28 +08:00
dudaodong	422022c74d	feat: add Range for stream	2023-02-07 10:36:07 +08:00
dudaodong	87fcf97e2d	feat: add FindFirst, Reverse for stream	2023-02-07 10:24:19 +08:00
dudaodong	05d1f348d4	refactor: update constant names	2023-02-06 19:39:31 +08:00
dudaodong	6f2f1f3004	fix: IsZeroValue support pointer	2023-02-06 19:36:36 +08:00