update readme file

Co-authored-by: wangxd01 <wangxd01@mingyuanyun.com>

README.md

@@ -4,13 +4,12 @@
 <br/>
 
 ![Go version](https://img.shields.io/badge/go-%3E%3D1.16<recommend>-9cf)
-[![Release](https://img.shields.io/badge/release-2.0.0-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-2.0.2-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)
 [![codecov](https://codecov.io/gh/duke-git/lancet/branch/main/graph/badge.svg?token=FC48T1F078)](https://codecov.io/gh/duke-git/lancet)
 [![License](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/duke-git/lancet/blob/main/LICENSE)
-
 </div>
 
 <div STYLE="page-break-after: always;"></div>
@@ -36,9 +35,9 @@ 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. now latest v1 is v1.2.6. </b>
+2. <b>For users who use version below go1.18, you should install v1.x.x. now latest v1 is v1.2.7. </b>
 ```go
-go get github.com/duke-git/lancet@v1.2.6 // below go1.18, install latest version of v1.x.x
+go get github.com/duke-git/lancet@v1.2.7 // below go1.18, install latest version of v1.x.x
 ```
 
 ## Usage
@@ -58,7 +57,7 @@ package main
 
 import (
     "fmt"
-    "github.com/duke-git/lancet/strutil"
+    "github.com/duke-git/lancet/v2/strutil"
 )
 
 func main() {
@@ -175,6 +174,14 @@ import "github.com/duke-git/lancet/v2/datetime"
 - [GetNightTimestamp](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#GetNightTimestamp)
 - [FormatTimeToStr](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#FormatTimeToStr)
 - [FormatStrToTime](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#FormatStrToTime)
+- [NewUnix](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#NewUnix)
+- [NewUnixNow](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#NewUnixNow)
+- [NewFormat](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#NewFormat)
+- [NewISO8601](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#NewISO8601)
+- [ToUnix](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#ToUnix)
+- [ToFormat](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#ToFormat)
+- [ToFormatForTpl](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#ToFormatForTpl)
+- [ToIso8601](https://github.com/duke-git/lancet/blob/main/docs/datetime.md#ToIso8601)
 
 ### Fileutil package implements some basic functions for file operations.
 
@@ -230,9 +237,12 @@ import "github.com/duke-git/lancet/v2/mathutil"
 ```
 
 #### Function list:
+- [Average](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Average)
 - [Exponent](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Exponent)
 - [Fibonacci](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Fibonacci)
 - [Factorial](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Factorial)
+- [Max](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Max)
+- [Min](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Min)
 - [Percent](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#Percent)
 - [RoundToFloat](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#RoundToFloat)
 - [RoundToString](https://github.com/duke-git/lancet/blob/main/docs/mathutil.md#RoundToString)
@@ -309,6 +319,7 @@ import "github.com/duke-git/lancet/v2/slice"
 - [FlattenDeep](#FlattenDeep)
 - [ForEach](https://github.com/duke-git/lancet/blob/main/docs/slice.md#ForEach)
 - [GroupBy](https://github.com/duke-git/lancet/blob/main/docs/slice.md#GroupBy)
+- [GroupWith](https://github.com/duke-git/lancet/blob/main/docs/slice.md#GroupWith)
 - [IntSlice](https://github.com/duke-git/lancet/blob/main/docs/slice.md#IntSlice)
 - [InterfaceSlice](https://github.com/duke-git/lancet/blob/main/docs/slice.md#InterfaceSlice)
 - [Intersection](https://github.com/duke-git/lancet/blob/main/docs/slice.md#Intersection)

README_zh-CN.md

@@ -4,13 +4,12 @@
 <br/>
 
 ![Go version](https://img.shields.io/badge/go-%3E%3D1.16<recommend>-9cf)
-[![Release](https://img.shields.io/badge/release-2.0.0-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-2.0.2-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)
 [![codecov](https://codecov.io/gh/duke-git/lancet/branch/main/graph/badge.svg?token=FC48T1F078)](https://codecov.io/gh/duke-git/lancet)
 [![License](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/duke-git/lancet/blob/main/LICENSE)
-
 </div>
 
 <div STYLE="page-break-after: always;"></div>
@@ -36,9 +35,9 @@
 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v1.2.6。</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v1.2.7。</b>
 ```go
-go get github.com/duke-git/lancet@v1.2.6 // 使用go1.18以下版本, 必须安装v1.x.x版本
+go get github.com/duke-git/lancet@v1.2.7 // 使用go1.18以下版本, 必须安装v1.x.x版本
 ```
 
 ## 用法
@@ -58,7 +57,7 @@ package main
 
 import (
     "fmt"
-    "github.com/duke-git/lancet/strutil"
+    "github.com/duke-git/lancet/v2/strutil"
 )
 
 func main() {
@@ -174,6 +173,14 @@ import "github.com/duke-git/lancet/v2/datetime"
 - [GetNightTimestamp](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#GetNightTimestamp)
 - [FormatTimeToStr](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#FormatTimeToStr)
 - [FormatStrToTime](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#FormatStrToTime)
+- [NewUnix](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#NewUnix)
+- [NewUnixNow](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#NewUnixNow)
+- [NewFormat](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#NewFormat)
+- [NewISO8601](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#NewISO8601)
+- [ToUnix](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#ToUnix)
+- [ToFormat](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#ToFormat)
+- [ToFormatForTpl](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#ToFormatForTpl)
+- [ToIso8601](https://github.com/duke-git/lancet/blob/main/docs/datetime_zh-CN.md#ToIso8601)
 
 ### fileutil包支持文件基本操作。
 
@@ -229,9 +236,12 @@ import "github.com/duke-git/lancet/v2/mathutil"
 ```
 
 #### Function list:
+- [Average](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Average)
 - [Exponent](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Exponent)
 - [Fibonacci](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Fibonacci)
 - [Factorial](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Factorial)
+- [Max](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Max)
+- [Min](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Min)
 - [Percent](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#Percent)
 - [RoundToFloat](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#RoundToFloat)
 - [RoundToString](https://github.com/duke-git/lancet/blob/main/docs/mathutil_zh-CN.md#RoundToString)
@@ -307,6 +317,7 @@ import "github.com/duke-git/lancet/v2/slice"
 - [FlattenDeep](#FlattenDeep)
 - [ForEach](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#ForEach)
 - [GroupBy](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#GroupBy)
+- [GroupWith](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#GroupWith)
 - [IntSlice](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#IntSlice)
 - [InterfaceSlice](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#InterfaceSlice)
 - [Intersection](https://github.com/duke-git/lancet/blob/main/docs/slice_zh-CN.md#Intersection)

algorithm/sorter.go

@@ -37,7 +37,7 @@ func InsertionSort[T any](slice []T, comparator lancetconstraints.Comparator) []
 			preIndex--
 		}
 
-		slice[preIndex+1] = preItem
+		slice[preIndex+1] = currentItem
 	}
 
 	return slice

algorithm/sorter_test.go

@@ -89,10 +89,10 @@ func TestInsertionSort(t *testing.T) {
 	asssert := internal.NewAssert(t, "TestInsertionSort")
 
 	comparator := &peopleAgeComparator{}
-	sortedPeopleByAge := SelectionSort(peoples, comparator)
+	sortedPeopleByAge := InsertionSort(peoples, comparator)
 	t.Log(sortedPeopleByAge)
 
-	expected := "[{d 8} {b 10} {c 17} {a 20} {e 28}]"
+	expected := "[{e 28} {a 20} {c 17} {b 10} {d 8}]"
 	actual := fmt.Sprintf("%v", sortedPeopleByAge)
 
 	asssert.Equal(expected, actual)

convertor/convertor.go

@@ -6,9 +6,10 @@ package convertor
 
 import (
 	"bytes"
-	"encoding/gob"
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
+	"math"
 	"reflect"
 	"regexp"
 	"strconv"
@@ -21,14 +22,44 @@ func ToBool(s string) (bool, error) {
 }
 
 // ToBytes convert interface to bytes
-func ToBytes(data any) ([]byte, error) {
-	var buf bytes.Buffer
-	enc := gob.NewEncoder(&buf)
-	err := enc.Encode(data)
-	if err != nil {
-		return nil, err
+func ToBytes(value any) ([]byte, error) {
+	v := reflect.ValueOf(value)
+
+	switch value.(type) {
+	case int, int8, int16, int32, int64:
+		number := v.Int()
+		buf := bytes.NewBuffer([]byte{})
+		buf.Reset()
+		err := binary.Write(buf, binary.BigEndian, number)
+		return buf.Bytes(), err
+	case uint, uint8, uint16, uint32, uint64:
+		number := v.Uint()
+		buf := bytes.NewBuffer([]byte{})
+		buf.Reset()
+		err := binary.Write(buf, binary.BigEndian, number)
+		return buf.Bytes(), err
+	case float32:
+		number := float32(v.Float())
+		bits := math.Float32bits(number)
+		bytes := make([]byte, 4)
+		binary.BigEndian.PutUint32(bytes, bits)
+		return bytes, nil
+	case float64:
+		number := v.Float()
+		bits := math.Float64bits(number)
+		bytes := make([]byte, 8)
+		binary.BigEndian.PutUint64(bytes, bits)
+		return bytes, nil
+	case bool:
+		return strconv.AppendBool([]byte{}, v.Bool()), nil
+	case string:
+		return []byte(v.String()), nil
+	case []byte:
+		return v.Bytes(), nil
+	default:
+		newValue, err := json.Marshal(value)
+		return newValue, err
 	}
-	return buf.Bytes(), nil
 }
 
 // ToChar convert string to char slice

convertor/convertor_test.go

@@ -42,14 +42,21 @@ func TestToBytes(t *testing.T) {
 		"1",
 	}
 	expected := [][]byte{
-		{3, 4, 0, 0},
-		{3, 2, 0, 0},
-		{4, 12, 0, 1, 49},
+		{0, 0, 0, 0, 0, 0, 0, 0},
+		{102, 97, 108, 115, 101},
+		{49},
 	}
 	for i := 0; i < len(cases); i++ {
 		actual, _ := ToBytes(cases[i])
 		assert.Equal(expected[i], actual)
 	}
+
+	bytesData, err := ToBytes("abc")
+	if err != nil {
+		t.Error(err)
+		t.Fail()
+	}
+	assert.Equal("abc", ToString(bytesData))
 }
 
 func TestToInt(t *testing.T) {

datastructure/link/doublylink_test.go

@@ -44,14 +44,11 @@ func TestDoublyLink_InsertAt(t *testing.T) {
 	err := link.InsertAt(1, 1)
 	assert.IsNotNil(err)
 
-	err = link.InsertAt(0, 1)
-	err = link.InsertAt(1, 2)
-	err = link.InsertAt(2, 4)
-	err = link.InsertAt(2, 3)
+	link.InsertAt(0, 1)
+	link.InsertAt(1, 2)
+	link.InsertAt(2, 4)
+	link.InsertAt(2, 3)
 
-	if err != nil {
-		t.FailNow()
-	}
 	link.Print()
 
 	expected := []int{1, 2, 3, 4}

datastructure/link/singlylink.go

@@ -3,6 +3,7 @@ package datastructure
 import (
 	"errors"
 	"fmt"
+	"reflect"
 
 	"github.com/duke-git/lancet/v2/datastructure"
 )
@@ -144,6 +145,27 @@ func (link *SinglyLink[T]) DeleteAt(index int) error {
 	return errors.New("delete error")
 }
 
+// DeleteValue delete value in singly linklist
+func (link *SinglyLink[T]) DeleteValue(value T) {
+	if link.Head == nil {
+		return
+	}
+	dummyHead := datastructure.NewLinkNode(value)
+	dummyHead.Next = link.Head
+	current := dummyHead
+
+	for current.Next != nil {
+		if reflect.DeepEqual(current.Next.Value, value) {
+			current.Next = current.Next.Next
+			link.length--
+		} else {
+			current = current.Next
+		}
+	}
+
+	link.Head = dummyHead.Next
+}
+
 // Reverse the linked list
 func (link *SinglyLink[T]) Reverse() {
 	var pre, next *datastructure.LinkNode[T]

datastructure/link/singlylink_test.go

@@ -45,20 +45,28 @@ func TestSinglyLink_InsertAt(t *testing.T) {
 	assert.IsNotNil(err)
 
 	err = link.InsertAt(0, 1)
-	err = link.InsertAt(1, 2)
-	err = link.InsertAt(2, 4)
-	err = link.InsertAt(2, 3)
-
 	if err != nil {
 		t.FailNow()
 	}
+	err = link.InsertAt(1, 2)
+	if err != nil {
+		t.FailNow()
+	}
+	err = link.InsertAt(2, 4)
+	if err != nil {
+		t.FailNow()
+	}
+	err = link.InsertAt(2, 3)
+	if err != nil {
+		t.FailNow()
+	}
+
 	link.Print()
 
 	expected := []int{1, 2, 3, 4}
 	values := link.Values()
 
 	assert.Equal(expected, values)
-
 }
 
 func TestSinglyLink_DeleteAtHead(t *testing.T) {
@@ -103,6 +111,24 @@ func TestSinglyLink_DeleteAtTail(t *testing.T) {
 	assert.Equal(expected, values)
 }
 
+func TestSinglyLink_DeleteValue(t *testing.T) {
+	assert := internal.NewAssert(t, "TestSinglyLink_DeleteValue")
+
+	link := NewSinglyLink[int]()
+
+	link.InsertAtTail(1)
+	link.InsertAtTail(2)
+	link.InsertAtTail(2)
+	link.InsertAtTail(3)
+	link.InsertAtTail(4)
+
+	link.DeleteValue(2)
+	assert.Equal([]int{1, 3, 4}, link.Values())
+
+	link.DeleteValue(1)
+	assert.Equal([]int{3, 4}, link.Values())
+}
+
 func TestSinglyLink_DeleteAt(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSinglyLink_DeleteAt")
 

datastructure/list/list_test.go

@@ -99,7 +99,7 @@ func TestPopFirst(t *testing.T) {
 	assert.Equal([]int{2, 3}, list.Data())
 
 	list2 := NewList([]int{})
-	v, ok = list2.PopFirst()
+	_, ok = list2.PopFirst()
 	assert.Equal(false, ok)
 	assert.Equal([]int{}, list2.Data())
 }
@@ -114,7 +114,7 @@ func TestPopLast(t *testing.T) {
 	assert.Equal([]int{1, 2}, list.Data())
 
 	list2 := NewList([]int{})
-	v, ok = list2.PopLast()
+	_, ok = list2.PopLast()
 	assert.Equal(false, ok)
 	assert.Equal([]int{}, list2.Data())
 }

datastructure/node.go

@@ -1,3 +1,7 @@
+// Copyright 2021 dudaodong@gmail.com. All rights reserved.
+// Use of this source code is governed by MIT license
+
+// Package datastructure implements some data structure. eg. list, linklist, stack, queue, tree, graph.
 package datastructure
 
 // LinkNode is a linkedlist node, which have a Value and Pre points to previous node, Next points to a next node of the link.

datastructure/queue/linkedqueue_test.go

@@ -40,14 +40,14 @@ func TestLinkedQueue_Front(t *testing.T) {
 	assert := internal.NewAssert(t, "TestLinkedQueue_Front")
 
 	queue := NewLinkedQueue[int]()
-	val, err := queue.Front()
+	_, err := queue.Front()
 	assert.IsNotNil(err)
 
 	queue.EnQueue(1)
 	queue.EnQueue(2)
 	queue.EnQueue(3)
 
-	val, err = queue.Front()
+	val, err := queue.Front()
 	assert.Equal(1, *val)
 	assert.IsNil(err)
 }
@@ -56,14 +56,14 @@ func TestLinkedQueue_Back(t *testing.T) {
 	assert := internal.NewAssert(t, "TestLinkedQueue_Back")
 
 	queue := NewLinkedQueue[int]()
-	val, err := queue.Back()
+	_, err := queue.Back()
 	assert.IsNotNil(err)
 
 	queue.EnQueue(1)
 	queue.EnQueue(2)
 	queue.EnQueue(3)
 
-	val, err = queue.Back()
+	val, err := queue.Back()
 	assert.Equal(3, *val)
 	assert.IsNil(err)
 }

datastructure/stack/arraystack_test.go

@@ -26,14 +26,14 @@ func TestArrayStack_Pop(t *testing.T) {
 	assert := internal.NewAssert(t, "TestArrayStack_Pop")
 
 	stack := NewArrayStack[int]()
-	topItem, err := stack.Pop()
+	_, err := stack.Pop()
 	assert.IsNotNil(err)
 
 	stack.Push(1)
 	stack.Push(2)
 	stack.Push(3)
 
-	topItem, err = stack.Pop()
+	topItem, err := stack.Pop()
 	assert.IsNil(err)
 	assert.Equal(3, *topItem)
 
@@ -45,14 +45,14 @@ func TestArrayStack_Peak(t *testing.T) {
 	assert := internal.NewAssert(t, "TestArrayStack_Peak")
 
 	stack := NewArrayStack[int]()
-	topItem, err := stack.Peak()
+	_, err := stack.Peak()
 	assert.IsNotNil(err)
 
 	stack.Push(1)
 	stack.Push(2)
 	stack.Push(3)
 
-	topItem, err = stack.Peak()
+	topItem, err := stack.Peak()
 	assert.IsNil(err)
 	assert.Equal(3, *topItem)
 

datastructure/stack/linkedstack_test.go

@@ -28,14 +28,14 @@ func TestLinkedStack_Pop(t *testing.T) {
 	assert := internal.NewAssert(t, "TestLinkedStack_Pop")
 
 	stack := NewLinkedStack[int]()
-	topItem, err := stack.Pop()
+	_, err := stack.Pop()
 	assert.IsNotNil(err)
 
 	stack.Push(1)
 	stack.Push(2)
 	stack.Push(3)
 
-	topItem, err = stack.Pop()
+	topItem, err := stack.Pop()
 	assert.IsNil(err)
 	assert.Equal(3, *topItem)
 
@@ -48,14 +48,14 @@ func TestLinkedStack_Peak(t *testing.T) {
 	assert := internal.NewAssert(t, "TestLinkedStack_Peak")
 
 	stack := NewLinkedStack[int]()
-	topItem, err := stack.Peak()
+	_, err := stack.Peak()
 	assert.IsNotNil(err)
 
 	stack.Push(1)
 	stack.Push(2)
 	stack.Push(3)
 
-	topItem, err = stack.Peak()
+	topItem, err := stack.Peak()
 	assert.IsNil(err)
 	assert.Equal(3, *topItem)
 

datetime/conversion.go

@@ -0,0 +1,60 @@
+// Copyright 2021 dudaodong@gmail.com. All rights reserved.
+// Use of this source code is governed by MIT license.
+
+package datetime
+
+import "time"
+
+type theTime struct {
+	unix int64
+}
+
+// NewUnixNow return unix timestamp of current time
+func NewUnixNow() *theTime {
+	return &theTime{unix: time.Now().Unix()}
+}
+
+// NewUnix return unix timestamp of specified time
+func NewUnix(unix int64) *theTime {
+	return &theTime{unix: unix}
+}
+
+// NewFormat return unix timestamp of specified time string, t should be "yyyy-mm-dd hh:mm:ss"
+func NewFormat(t string) (*theTime, error) {
+	timeLayout := "2006-01-02 15:04:05"
+	loc := time.FixedZone("CST", 8*3600)
+	tt, err := time.ParseInLocation(timeLayout, t, loc)
+	if err != nil {
+		return nil, err
+	}
+	return &theTime{unix: tt.Unix()}, nil
+}
+
+// NewISO8601 return unix timestamp of specified iso8601 time string
+func NewISO8601(iso8601 string) (*theTime, error) {
+	t, err := time.ParseInLocation(time.RFC3339, iso8601, time.UTC)
+	if err != nil {
+		return nil, err
+	}
+	return &theTime{unix: t.Unix()}, nil
+}
+
+// ToUnix return unix timestamp
+func (t *theTime) ToUnix() int64 {
+	return t.unix
+}
+
+// ToFormat return the time string 'yyyy-mm-dd hh:mm:ss' of unix time
+func (t *theTime) ToFormat() string {
+	return time.Unix(t.unix, 0).Format("2006-01-02 15:04:05")
+}
+
+// ToFormatForTpl return the time string which format is specified tpl
+func (t *theTime) ToFormatForTpl(tpl string) string {
+	return time.Unix(t.unix, 0).Format(tpl)
+}
+
+// ToFormatForTpl return iso8601 time string
+func (t *theTime) ToIso8601() string {
+	return time.Unix(t.unix, 0).Format(time.RFC3339)
+}

datetime/conversion_test.go

@@ -0,0 +1,53 @@
+package datetime
+
+import (
+	"testing"
+
+	"github.com/duke-git/lancet/v2/internal"
+)
+
+func TestToUnix(t *testing.T) {
+	assert := internal.NewAssert(t, "TestToUnix")
+
+	tm1 := NewUnixNow()
+	unixTimestamp := tm1.ToUnix()
+	tm2 := NewUnix(unixTimestamp)
+
+	assert.Equal(tm1, tm2)
+}
+
+func TestToFormat(t *testing.T) {
+	assert := internal.NewAssert(t, "TestToFormat")
+
+	_, err := NewFormat("2022/03/18 17:04:05")
+	assert.IsNotNil(err)
+
+	tm, err := NewFormat("2022-03-18 17:04:05")
+	assert.IsNil(err)
+
+	t.Log("ToFormat -> ", tm.ToFormat())
+}
+
+func TestToFormatForTpl(t *testing.T) {
+	assert := internal.NewAssert(t, "TestToFormatForTpl")
+
+	_, err := NewFormat("2022/03/18 17:04:05")
+	assert.IsNotNil(err)
+
+	tm, err := NewFormat("2022-03-18 17:04:05")
+	assert.IsNil(err)
+
+	t.Log("ToFormatForTpl -> ", tm.ToFormatForTpl("2006/01/02 15:04:05"))
+}
+
+func TestToIso8601(t *testing.T) {
+	assert := internal.NewAssert(t, "TestToIso8601")
+
+	_, err := NewISO8601("2022-03-18 17:04:05")
+	assert.IsNotNil(err)
+
+	tm, err := NewISO8601("2006-01-02T15:04:05.999Z")
+	assert.IsNil(err)
+
+	t.Log("ToIso8601 -> ", tm.ToIso8601())
+}

docs/datetime.md

@@ -6,6 +6,7 @@ Package datetime supports date and time format and compare.
 ## Source:
 
 - [https://github.com/duke-git/lancet/blob/main/datetime/datetime.go](https://github.com/duke-git/lancet/blob/main/datetime/datetime.go)
+- [https://github.com/duke-git/lancet/blob/main/datetime/conversion.go](https://github.com/duke-git/lancet/blob/main/datetime/conversion.go)
 
 <div STYLE="page-break-after: always;"></div>
 
@@ -28,7 +29,6 @@ import (
 - [BeginOfWeek](#BeginOfWeek)
 - [BeginOfMonth](#BeginOfMonth)
 - [BeginOfYear](#BeginOfYear)
-
 - [EndOfMinute](#EndOfMinute)
 - [EndOfHour](#EndOfHour)
 - [EndOfDay](#EndOfDay)
@@ -41,9 +41,19 @@ import (
 - [GetZeroHourTimestamp](#GetZeroHourTimestamp)
 - [GetNightTimestamp](#GetNightTimestamp)
 - [FormatTimeToStr](#FormatTimeToStr)
-
 - [FormatStrToTime](#FormatStrToTime)
 
+- [NewUnixNow](#NewUnixNow)
+- [NewUnix](#NewUnix)
+- [NewFormat](#NewFormat)
+- [NewISO8601](#NewISO8601)
+- [ToUnix](#ToUnix)
+- [ToFormat](#ToFormat)
+- [ToFormatForTpl](#ToFormatForTpl)
+- [ToIso8601](#ToIso8601)
+
+
+
 <div STYLE="page-break-after: always;"></div>
 
 ## Documentation
@@ -667,3 +677,221 @@ func main() {
 
 
 
+### <span id="NewUnixNow">NewUnixNow</span>
+<p>Return unix timestamp of current time</p>
+
+<b>Signature:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewUnixNow() *theTime
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnixNow()
+    fmt.Println(tm) //&{1647597438}
+}
+```
+
+
+### <span id="NewUnix">NewUnix</span>
+<p>Return unix timestamp of specified int64 value.</p>
+
+<b>Signature:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewUnix(unix int64) *theTime
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnix(1647597438)
+    fmt.Println(tm) //&{1647597438}
+}
+```
+
+
+
+### <span id="NewFormat">NewFormat</span>
+<p>Return unix timestamp of specified time string, t should be "yyyy-mm-dd hh:mm:ss".</p>
+
+<b>Signature:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewFormat(t string) (*theTime, error)
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, err := datetime.NewFormat("2022-03-18 17:04:05")
+    fmt.Println(tm) //&{1647594245}
+}
+```
+
+
+
+
+### <span id="NewISO8601">NewISO8601</span>
+<p>Return unix timestamp of specified iso8601 time string.</p>
+
+<b>Signature:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewISO8601(iso8601 string) (*theTime, error)
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, err := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
+    fmt.Println(tm) //&{1136214245}
+}
+```
+
+
+
+### <span id="ToUnix">ToUnix</span>
+<p>Return unix timestamp.</p>
+
+<b>Signature:</b>
+
+```go
+func (t *theTime) ToUnix() int64
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnixNow()
+    fmt.Println(tm.ToUnix()) //1647597438
+}
+```
+
+
+
+### <span id="ToFormat">ToFormat</span>
+<p>Return time string 'yyyy-mm-dd hh:mm:ss'.</p>
+
+<b>Signature:</b>
+
+```go
+func (t *theTime) ToFormat() string
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
+    fmt.Println(tm.ToFormat()) //"2022-03-18 17:04:05"
+}
+```
+
+
+
+### <span id="ToFormatForTpl">ToFormatForTpl</span>
+<p>Return the time string which format is specified tpl.</p>
+
+<b>Signature:</b>
+
+```go
+func (t *theTime) ToFormatForTpl(tpl string) string
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
+    ts := tm.ToFormatForTpl("2006/01/02 15:04:05")
+    fmt.Println(ts) //"2022/03/18 17:04:05"
+}
+```
+
+
+### <span id="ToIso8601">ToIso8601</span>
+<p>Return iso8601 time string.</p>
+
+<b>Signature:</b>
+
+```go
+func (t *theTime) ToIso8601() string
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
+    ts := tm.ToIso8601()
+    fmt.Println(ts) //"2006-01-02T23:04:05+08:00"
+}
+```

docs/datetime_zh-CN.md

@@ -28,7 +28,6 @@ import (
 - [BeginOfWeek](#BeginOfWeek)
 - [BeginOfMonth](#BeginOfMonth)
 - [BeginOfYear](#BeginOfYear)
-
 - [EndOfMinute](#EndOfMinute)
 - [EndOfHour](#EndOfHour)
 - [EndOfDay](#EndOfDay)
@@ -43,6 +42,15 @@ import (
 - [FormatTimeToStr](#FormatTimeToStr)
 - [FormatStrToTime](#FormatStrToTime)
 
+- [NewUnixNow](#NewUnixNow)
+- [NewUnix](#NewUnix)
+- [NewFormat](#NewFormat)
+- [NewISO8601](#NewISO8601)
+- [ToUnix](#ToUnix)
+- [ToFormat](#ToFormat)
+- [ToFormatForTpl](#ToFormatForTpl)
+- [ToIso8601](#ToIso8601)
+
 <div STYLE="page-break-after: always;"></div>
 
 ## 文档
@@ -665,4 +673,221 @@ func main() {
 ```
 
 
+### <span id="NewUnixNow">NewUnixNow</span>
+<p>创建一个当前时间的unix时间戳</p>
 
+<b>函数签名:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewUnixNow() *theTime
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnixNow()
+    fmt.Println(tm) //&{1647597438}
+}
+```
+
+
+### <span id="NewUnix">NewUnix</span>
+<p>创建一个unix时间戳</p>
+
+<b>函数签名:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewUnix(unix int64) *theTime
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnix(1647597438)
+    fmt.Println(tm) //&{1647597438}
+}
+```
+
+
+
+### <span id="NewFormat">NewFormat</span>
+<p>创建一个yyyy-mm-dd hh:mm:ss格式时间字符串的unix时间戳</p>
+
+<b>函数签名:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewFormat(t string) (*theTime, error)
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, err := datetime.NewFormat("2022-03-18 17:04:05")
+    fmt.Println(tm) //&{1647594245}
+}
+```
+
+
+
+
+### <span id="NewISO8601">NewISO8601</span>
+<p>创建一个iso8601格式时间字符串的unix时间戳</p>
+
+<b>函数签名:</b>
+
+```go
+type theTime struct {
+	unix int64
+}
+func NewISO8601(iso8601 string) (*theTime, error)
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, err := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
+    fmt.Println(tm) //&{1136214245}
+}
+```
+
+
+
+### <span id="ToUnix">ToUnix</span>
+<p>返回unix时间戳</p>
+
+<b>函数签名:</b>
+
+```go
+func (t *theTime) ToUnix() int64
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm := datetime.NewUnixNow()
+    fmt.Println(tm.ToUnix()) //1647597438
+}
+```
+
+
+
+### <span id="ToFormat">ToFormat</span>
+<p>返回格式'yyyy-mm-dd hh:mm:ss'的日期字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func (t *theTime) ToFormat() string
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
+    fmt.Println(tm.ToFormat()) //"2022-03-18 17:04:05"
+}
+```
+
+
+
+### <span id="ToFormatForTpl">ToFormatForTpl</span>
+<p>返回tpl格式指定的日期字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func (t *theTime) ToFormatForTpl(tpl string) string
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewFormat("2022-03-18 17:04:05")
+    ts := tm.ToFormatForTpl("2006/01/02 15:04:05")
+    fmt.Println(ts) //"2022/03/18 17:04:05"
+}
+```
+
+
+### <span id="ToIso8601">ToIso8601</span>
+<p>返回iso8601日期字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func (t *theTime) ToIso8601() string
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/datetime"
+)
+
+func main() {
+    tm, _ := datetime.NewISO8601("2006-01-02T15:04:05.999Z")
+    ts := tm.ToIso8601()
+    fmt.Println(ts) //"2006-01-02T23:04:05+08:00"
+}
+```

docs/mathutil.md

@@ -20,9 +20,13 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## Index
+- [Average](#Average)
 - [Exponent](#Exponent)
 - [Fibonacci](#Fibonacci)
 - [Factorial](#Factorial)
+- [Max](#Max)
+- [Min](#Min)
+
 - [Percent](#Percent)
 - [RoundToFloat](#RoundToFloat)
 - [RoundToString](#RoundToString)
@@ -33,6 +37,35 @@ import (
 ## Documentation
 
 
+
+### <span id="Average">Average</span>
+<p>Return average value of numbers. Maybe call RoundToFloat to round result.</p>
+
+<b>Signature:</b>
+
+```go
+func Average[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Average(0, 0)) //0
+	fmt.Println(mathutil.Average(1, 1)) //1
+	avg := mathutil.Average(1.2, 1.4) //1.2999999998
+	roundAvg := mmathutil.RoundToFloat(avg, 1) // 1.3
+}
+```
+
+
+
 ### <span id="Exponent">Exponent</span>
 <p>Calculate x to the nth power.</p>
 
@@ -117,6 +150,60 @@ func main() {
 
 
 
+### <span id="Max">Max</span>
+<p>Return max value of numbers.</p>
+
+<b>Signature:</b>
+
+```go
+func Max[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Max(0, 0)) //0
+	fmt.Println(mathutil.Max(1, 2, 3)) //3
+	fmt.Println(mathutil.Max(1.2, 1.4, 1.1, 1.4)) //1.4
+}
+```
+
+
+
+### <span id="Min">Min</span>
+<p>Return min value of numbers.</p>
+
+<b>Signature:</b>
+
+```go
+func Min[T lancetconstraints.Number](numbers ...T) T
+```
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Min(0, 0)) //0
+	fmt.Println(mathutil.Min(1, 2, 3)) //1
+	fmt.Println(mathutil.Min(1.2, 1.4, 1.1, 1.4)) //1.1
+}
+```
+
+
+
 ### <span id="Percent">Percent</span>
 <p>calculate the percentage of val to total, retain n decimal places.</p>
 

docs/mathutil_zh-CN.md

@@ -20,10 +20,13 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## 目录
+- [Average](#Average)
 - [Exponent](#Exponent)
 - [Fibonacci](#Fibonacci)
 - [Factorial](#Factorial)
-
+- [Max](#Max)
+- [Min](#Min)
+  
 - [Percent](#Percent)
 - [RoundToFloat](#RoundToFloat)
 - [RoundToString](#RoundToString)
@@ -34,6 +37,33 @@ import (
 ## Documentation
 
 
+### <span id="Average">Average</span>
+<p>计算平均数. 可能需要对结果调用RoundToFloat方法四舍五入</p>
+
+<b>函数签名:</b>
+
+```go
+func Average[T lancetconstraints.Number](numbers ...T) T
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Average(0, 0)) //0
+	fmt.Println(mathutil.Average(1, 1)) //1
+	avg := mathutil.Average(1.2, 1.4) //1.2999999998
+	roundAvg := mmathutil.RoundToFloat(avg, 1) // 1.3
+}
+```
+
+
 ### <span id="Exponent">Exponent</span>
 <p>指数计算（x的n次方）</p>
 
@@ -117,6 +147,59 @@ func main() {
 ```
 
 
+### <span id="Max">Max</span>
+<p>返回参数中的最大数</p>
+
+<b>函数签名:</b>
+
+```go
+func Max[T lancetconstraints.Number](numbers ...T) T
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Max(0, 0)) //0
+	fmt.Println(mathutil.Max(1, 2, 3)) //3
+	fmt.Println(mathutil.Max(1.2, 1.4, 1.1, 1.4)) //1.4
+}
+```
+
+
+
+### <span id="Min">Min</span>
+<p>返回参数中的最小数</p>
+
+<b>函数签名:</b>
+
+```go
+func Min[T lancetconstraints.Number](numbers ...T) T
+```
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/mathutil"
+)
+
+func main() {
+	fmt.Println(mathutil.Min(0, 0)) //0
+	fmt.Println(mathutil.Min(1, 2, 3)) //1
+	fmt.Println(mathutil.Min(1.2, 1.4, 1.1, 1.4)) //1.1
+}
+```
+
+
 
 ### <span id="Percent">Percent</span>
 <p>计算百分比，保留n位小数</p>

docs/slice.md

@@ -37,8 +37,9 @@ import (
 - [FindLast](#FindLast)
 - [FlattenDeep](#FlattenDeep)
 - [ForEach](#ForEach)
-  
+
 - [GroupBy](#GroupBy)
+- [GroupWith](#GroupWith)
 - [IntSlice](#IntSlice)
 - [InterfaceSlice](#InterfaceSlice)
 - [Intersection](#Intersection)
@@ -564,6 +565,34 @@ func main() {
 
 
 
+### <span id="GroupWith">GroupWith</span>
+<p>Return a map composed of keys generated from the results of running each element of slice thru iteratee.</p>
+
+<b>Signature:</b>
+
+```go
+func GroupWith[T any, U comparable](slice []T, iteratee func(T) U) map[U][]T 
+```
+<b>Example:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+	nums := []float64{6.1, 4.2, 6.3}
+	floor := func(num float64) float64 {
+		return math.Floor(num)
+	}
+	res := slice.GroupWith(nums, floor)
+	fmt.Println(res) //map[float64][]float64{ 4: {4.2}, 6: {6.1, 6.3},}
+}
+```
+
+
+
 ### <span id="IntSlice">IntSlice</span>
 <p>Convert interface slice to int slice.</p>
 

docs/slice_zh-CN.md

@@ -39,6 +39,7 @@ import (
 - [ForEach](#ForEach)
   
 - [GroupBy](#GroupBy)
+- [GroupWith](#GroupWith)
 - [IntSlice](#IntSlice)
 - [InterfaceSlice](#InterfaceSlice)
 - [Intersection](#Intersection)
@@ -565,6 +566,32 @@ func main() {
 
 
 
+### <span id="GroupWith">GroupWith</span>
+<p>创建一个map，key是iteratee遍历slice中的每个元素返回的结果。 分组值的顺序是由他们出现在slice中的顺序确定的。每个键对应的值负责生成key的元素组成的数组。iteratee调用1个参数： (value)</p>
+
+<b>函数签名:</b>
+
+```go
+func GroupWith[T any, U comparable](slice []T, iteratee func(T) U) map[U][]T 
+```
+<b>例子:</b>
+
+```go
+import (
+	"fmt"
+	"github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+	nums := []float64{6.1, 4.2, 6.3}
+	floor := func(num float64) float64 {
+		return math.Floor(num)
+	}
+	res := slice.GroupWith(nums, floor)
+	fmt.Println(res) //map[float64][]float64{ 4: {4.2}, 6: {6.1, 6.3},}
+}
+```
+
 
 ### <span id="IntSlice">IntSlice</span>
 <p>将接口切片转换为int切片</p>

fileutil/file_test.go

@@ -76,10 +76,10 @@ func TestCopyFile(t *testing.T) {
 func TestListFileNames(t *testing.T) {
 	assert := internal.NewAssert(t, "TestListFileNames")
 
-	filesInPath, err := ListFileNames("../datetime/")
+	filesInPath, err := ListFileNames("./")
 	assert.IsNil(err)
 
-	expected := []string{"datetime.go", "datetime_test.go"}
+	expected := []string{"file.go", "file_test.go"}
 	assert.Equal(expected, filesInPath)
 }
 

lancetconstraints/constraints.go

@@ -11,3 +11,8 @@ type Comparator interface {
 	// Descending order: should return 1 -> v1 < v2, 0 -> v1 = v2, -1 -> v1 > v2
 	Compare(v1, v2 any) int
 }
+
+// Number contains all types of number and uintptr, used for generics constraint
+type Number interface {
+	int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64 | uintptr | float32 | float64
+}

mathutil/mathutil.go

@@ -9,6 +9,8 @@ import (
 	"math"
 	"strconv"
 	"strings"
+
+	"github.com/duke-git/lancet/v2/lancetconstraints"
 )
 
 // Exponent calculate x^n
@@ -90,3 +92,40 @@ func TruncRound(x float64, n int) float64 {
 	res, _ := strconv.ParseFloat(newFloat, 64)
 	return res
 }
+
+// Max return max value of params
+func Max[T lancetconstraints.Number](numbers ...T) T {
+	max := numbers[0]
+
+	for _, v := range numbers {
+		if max < v {
+			max = v
+		}
+	}
+
+	return max
+}
+
+// Min return min value of params
+func Min[T lancetconstraints.Number](numbers ...T) T {
+	min := numbers[0]
+
+	for _, v := range numbers {
+		if min > v {
+			min = v
+		}
+	}
+
+	return min
+}
+
+// Average return average value of params
+func Average[T lancetconstraints.Number](numbers ...T) T {
+	var sum T
+	n := T(len(numbers))
+
+	for _, v := range numbers {
+		sum += v
+	}
+	return sum / n
+}

mathutil/mathutil_test.go

@@ -70,3 +70,29 @@ func TestTruncRound(t *testing.T) {
 	assert.Equal(TruncRound(0.125, 3), float64(0.125))
 	assert.Equal(TruncRound(33.33333, 2), float64(33.33))
 }
+
+func TestAverage(t *testing.T) {
+	assert := internal.NewAssert(t, "TestAverage")
+
+	assert.Equal(Average(0, 0), 0)
+	assert.Equal(Average(1, 1), 1)
+	avg := Average(1.2, 1.4)
+	t.Log(avg)
+	assert.Equal(1.3, RoundToFloat(avg, 1))
+}
+
+func TestMax(t *testing.T) {
+	assert := internal.NewAssert(t, "TestMax")
+
+	assert.Equal(Max(0, 0), 0)
+	assert.Equal(Max(1, 2, 3), 3)
+	assert.Equal(Max(1.2, 1.4, 1.1, 1.4), 1.4)
+}
+
+func TestMin(t *testing.T) {
+	assert := internal.NewAssert(t, "TestMin")
+
+	assert.Equal(Min(0, 0), 0)
+	assert.Equal(Min(1, 2, 3), 1)
+	assert.Equal(Min(1.2, 1.4, 1.1, 1.4), 1.1)
+}

slice/slice.go

@@ -253,6 +253,25 @@ func GroupBy[T any](slice []T, groupFn func(index int, t T) bool) ([]T, []T) {
 	return groupA, groupB
 }
 
+// GroupWith return a map composed of keys generated from the results of running each element of slice thru iteratee.
+func GroupWith[T any, U comparable](slice []T, iteratee func(T) U) map[U][]T {
+	if iteratee == nil {
+		panic("iteratee func is missing")
+	}
+
+	res := make(map[U][]T)
+
+	for _, v := range slice {
+		key := iteratee(v)
+		if _, ok := res[key]; !ok {
+			res[key] = []T{}
+		}
+		res[key] = append(res[key], v)
+	}
+
+	return res
+}
+
 // Find iterates over elements of slice, returning the first one that passes a truth test on predicate function.
 // If return T is nil then no items matched the predicate func
 func Find[T any](slice []T, predicate func(index int, t T) bool) (*T, bool) {

slice/slice_test.go

@@ -1,6 +1,7 @@
 package slice
 
 import (
+	"math"
 	"testing"
 
 	"github.com/duke-git/lancet/v2/internal"
@@ -142,6 +143,20 @@ func TestGroupBy(t *testing.T) {
 	assert.Equal(expectedOdd, odd)
 }
 
+func TestGroupWith(t *testing.T) {
+	nums := []float64{6.1, 4.2, 6.3}
+	floor := func(num float64) float64 {
+		return math.Floor(num)
+	}
+	expected := map[float64][]float64{
+		4: {4.2},
+		6: {6.1, 6.3},
+	}
+	actual := GroupWith(nums, floor)
+	assert := internal.NewAssert(t, "TestGroupWith")
+	assert.Equal(expected, actual)
+}
+
 func TestCount(t *testing.T) {
 	nums := []int{1, 2, 3, 4, 5, 6}
 	evenFunc := func(i, num int) bool {