Underscore.go

All(source, predicate)

Arguments

• source - array or map
• predicate - func(element, index or key) bool

Return

• bool - all the values that pass a truth test predicate

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 1, Name: "two"},
	{ID: 1, Name: "three"},
}
ok := All(src, func(r testModel, _ int) bool {
	return r.Id == 1
})
// ok == true

AllBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• bool

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 1, Name: "two"},
	{ID: 1, Name: "three"},
}
ok := AllBy(src, nil)
// ok == true

ok = AllBy(src, map[string]interface{}{
	"name": "a",
})
// ok == false

ok = AllBy(src, map[string]interface{}{
	"id": 1,
})
// ok == true

Any(source, predicate)

Arguments

• source - array or map
• predicate - func(element or value, index or key) bool

Return

• bool - any of the values that pass a truth test predicate

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
ok := Any(src, func(r testModel, _ int) bool {
	return r.Id == 0
})
// ok == false

AnyBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• bool

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
ok := AnyBy(src, map[string]interface{}{
	"Id": 0,
})
// ok == false

ok = AnyBy(src, map[string]interface{}{
	"id":   src[0].Id,
	"name": src[0].Name,
})
// ok == true

Chain(source).AsParallel()...

Support

• Each
• Object

Examples

arr := []int{ 1, 2, 3 }
Chain(arr).AsParallel().Each(func (n, i int) {
	// code
})

Chain(source)

Arguments

• source - array or map

Return

• IQuery - a wrapped object, wrapped objects until value is called

Examples

res := make(map[string][]int)
Chain([]int{1, 2, 1, 4, 1, 3}).Uniq(nil).Group(func(n, _ int) string {
	if n%2 == 0 {
		return "even"
	}

	return "old"
}).Value(&res)
// len(res) == 2 && ok == true

Clone()

Return

• interface{}

Examples

arr := []int{1, 2, 3}
var duplicate []int
Chain(arr).Clone().Value(&duplicate)
// or
duplicate := Clone(arr)
ok := All(duplicate, func(n, i int) bool {
	return arr[i] == n
})
// ok == true

Each(source, iterator)

Arguments

• source - array or map
• iterator - func(element or value, index or key)

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 1, Name: "two"},
	{ID: 1, Name: "three"},
}
Each(src, func (r testModel, i int) {
	// coding
})

Find(source, predicate)

Arguments

• source - array or map
• predicate - func(element or value, index or key) bool

Return

• interface{} -- source elem

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var item testModel
Chain(src).Find(func(r testModel, _ int) bool {
	return r.ID == 1
}).Value(&item)
// or
item := Find(src, func(r testModel, _ int) bool {
	return r.ID == 1
})
// item == arr[0]

FindBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• interface{} - source elem

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var item testModel
Chain(arr).FindBy(map[string]interface{}{
	"id": 2,
}).Value(&item)
// or
item := FindBy(arr, map[string]interface{}{
	"id": 2,
})
// item == arr[1]

FindIndex(source, predicate)

Arguments

• source - array or map
• predicate - func(element or value, index or key) bool

Return

• int - index

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 1, Name: "two"},
	{ID: 1, Name: "three"},
}
i := FindIndex(arr, func(r testModel, _ int) bool {
	return r.Name == arr[1].Name
})
// i == 1

FindIndexBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• int - index

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
i := FindIndexBy(arr, map[string]interface{}{
	"id": 1,
})
// i == 0

First(source)

Arguments

• source - array or map

Return

• interface{}

Examples

arr := []int{ 1, 2, 3 }
var res int
Chain(arr).First().Value(&res)
// or
res := First(arr).(int)
// res = 1

res := First(nil) 
// res == nil

Group(source, keySelector)

Arguments

• source - array or map
• keySelector - func(element or value, index or key) anyType

Return

• interface{} - map[anyType][](element or value)

Examples

src := []int{ 1, 2, 3, 4, 5 }
var res map[string][]int
Chain(src).Group(func (n, _ int) string {
	if n % 2 == 0 {
		return "even"
	}
	return "odd"
}).Value(&res)
// or
res := Group(src, func (n, _ int) string {
	if n % 2 == 0 {
		return "even"
	}
	return "odd"
}).(map[string][]int)
// res = map[odd:[1 3 5] even:[2 4]]

GroupBy(source, property)

Arguments

• source - array or map
• property - property name

Return

• interface{} - map[property type][](element or value)

Examples

arr := []testModel{
	{ID: 1, Name: "a"},
	{ID: 2, Name: "a"},
	{ID: 3, Name: "b"},
	{ID: 4, Name: "b"},
}
var res map[string][]testModel
Chain(arr).GroupBy("name").Value(&res)
// or
res := GroupBy(arr, "name").(map[string][]testModel)
// res = map[a:[{{0} 1 a} {{0} 2 a}] b:[{{0} 3 b} {{0} 4 b}]]

Index(source, indexSelector)

Arguments

• source - array or map
• indexSelector - func(element or value, index or key) anyType

Return

• interface{} - map[anyType](element or value)

Examples

src := []string{ "a", "b" }
var res map[string]string
Chain(src).Index(func (r string, _ int) string {
	return r
}).Value(&res)
// or
res := Index(src, func (r string, _ int) string {
	return r
}).(map[string]string)
// res = map[a:a b:b]

IndexBy(source, property)

Arguments

• source - array or map
• property - string

Return

• interface{} - map[propertyType](element or value)

Examples

arr := []testModel{
	{ID: 1, Name: "a"},
	{ID: 2, Name: "a"},
	{ID: 3, Name: "b"},
	{ID: 4, Name: "b"},
}
var res map[int]testModel
Chain(arr).IndexBy("id").Value(&res)
// or
res := IndexBy(arr, "id").(map[int]testModel)
// res = map[1:{{0} 1 a} 2:{{0} 2 a} 3:{{0} 3 b} 4:{{0} 4 b}]

IsArray(element)

Arguments

• element - object

Return

• bool

Examples

if !IsArray([]int{}) {
	// wrong
}

if IsArray(map[string]int{}) {
	// wrong
}

IsMatch(element, properties)

Arguments

• element - object
• properties - map[string]interface{}

Return

• bool

Examples

m := testModel{ 1, "one" }
ok := IsMatch(nil, nil)
// ok = false

ok = IsMatch(m, nil)
// ok = false

ok = IsMatch(m, map[string]interface{}{
	"id": m.Id,
	"name": "a",
})
// ok = false

ok = IsMatch(m, map[string]interface{}{
	"id": m.Id,
	"name": m.Name,
})
// ok = true

Keys()

Arguments

• source - map

Return

• interface{} - []keyType

Examples

arr := []string{ "aa" }
v := Keys(arr)
// v = nil

dict := map[int]string{	
	1: "a",
	2: "b",
	3: "c",
	4: "d",
}
var res []int
Chain(dict).Keys().Value(&res)
// or
res := Keys(dict).([]int)
// res = [1 2 3 4]

Last(source)

Arguments

• source - array or map

Return

• interface{} - last element of source

Examples

arr := []int{1, 2, 3}
var res int
chain(arr).Last().Value(&res)
// or
res := Last(arr).(int)
// res = 3

dict := map[string]string{
	"a": "aa",
	"b": "bb",
}
var str string
Chain(dict).Last().Value(&str)
// or
str := Last(dict).(string)
// res = "aa" or "bb"

Map(source, selector)

Arguments

• source - array or map
• selector - func(element, index or key) anyType

Return

• interface{} - an slice of property value

Examples

arr := []string{ "11", "12", "13" }
var res []int
Chain(arr).Map(func (s string, _ int) int {
	n, _ := strconv.Atoi(s)
	return n
}).Value(&res)
// or
res := Map(arr, func (s string, _ int) int {
	n, _ := strconv.Atoi(s)
	return n
}).([]int)
// res = [11 12 13]

MapBy(source, property)

Arguments

• source - array
• property - string

Return

• interface{} - an slice of property value

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var res []string
Chain(arr).MapBy("name").Value(&res)
// or
res := MapBy(arr, "name").([]string)
// res = [one two three]

MapMany(source, selector)

Arguments

• source - array or map
• selector - func(element, index or key) anyType with array or slice

Return

• interface{} - an slice of property elem value

Examples

src := []int{1, 2}
MapMany(src, func(r, _ int) int {
	return r // will panic because `r` is not array or slice
})
// or
Chain(src).MapMany(func(r, _ int) int {
	return r // will panic because `r` is not array or slice
})

var res []int
Chain(src).MapMany(func(r, _ int) []int {
	var temp []int
	Range(0, r, 1).Map(func(_, _ int) int {
		return r
	}).Value(&temp)
	return temp
}).Value(&res)
// or
res := MapMany(src, func(r, _ int) []int {
	var temp []int
	Range(0, r, 1).Map(func(_, _ int) int {
		return r
	}).Value(&temp)
	return temp
}).([]int)
// res = [1 2 2]

MapManyBy(source, property)

Arguments

• source - array
• property - string

Return

• interface{} - an slice of propery elem value

Examples

src := []mapManyTestModel{
	{Slice: []string{"a", "b"}},
	{Slice: []string{"c", "d"}},
}
Chain(src).MapManyBy("Str") // will panic because `Str` property value is not array or slice
// or
MapManyBy(src, "Str") // will panic because `Str` property value is not array or slice

var res []string
Chain(src).MapManyBy("Slice").Value(&res)
// or
res := MapManyBy(src, "Slice").([]string)
// res = [a b c d]

Md5(plaintext)

Arguments

• plaintext - string

Return

• string - md5 string

Examples

if Md5("123456") != "e10adc3949ba59abbe56e057f20f883e" {
	// wrong
}	

Object(arr)

Arguments

• arr - array

Return

• map, error

Examples

arr := []interface{}{
	[]interface{}{"a", 1},
	[]interface{}{"b", 2},
}
var res map[string]int
Chain(arr).Object().Value(&res)
// or
res := Object(arr).(map[string]int)
// res = map[b:2 a:1] or map[a:1 b:2]

Property(name)

Arguments

• name - property name

Return

• func(interface{}) (interface{}, error)

Examples

item := testModel{ 1, "one" }

getAge := Property("age")
_, err := getAge(item)
// err != nil

getName := Property("name")
name, err := getName(item)
// name = "one"

Property(name)

Arguments

• name - property name

Return

• func(interface{}) (reflect.Value, error)

Examples

item := testModel{ 1, "one" }

getAgeRV := PropertyRV("age")
_, err := getAgeRV(item)
// err != nil

getNameRV := PropertyRV("name")
nameRV, err := getNameRV(item)
// nameRV = reflect.ValueOf("one")

Range(start, stop, step)

Arguments

• start - int
• stop - int
• step - int

Return

• IQuery - a wrapped object, wrapped objects until value is called

Examples

var res []int
Range(0, 0, 1).Value(&res)
// res = []

var res []int
Range(0, 10, 0).Value(&res)
// res = []

var res []int
Range(10, 0, 1).Value(&res)
// res = []

var res []int
Range(0, 2, 1).Value(&res)
// res = [0 1]

var res []int
Range(0, 3, 2).Value(&res)
// res = [0 2]

Reduce(source, iterator)

Arguments

• source - array
• iterator - func(memo, element or value, key or index) memo
• memo - anyType

Return

• interface{} - memo

Examples

var res []int
Chain([]int{1, 2}).Reduce(func(memo []int, n, _ int) []int {
	memo = append(memo, n)
	memo = append(memo, n+10)
	return memo
}, make([]int, 0)).Value(&res)
// or
res := Reduce([]int{1, 2}, func(memo []int, n, _ int) []int {
	memo = append(memo, n)
	memo = append(memo, n+10)
	return memo
}, make([]int, 0)).([]int)
// res = [1 11 2 12]

Reject(source, predicate)

Arguments

• source - array or map
• predicate - func(element or value, index or key) bool

Return

• interface{} - an array of all the values that without pass a truth test predicate

Examples

arr := []int{1, 2, 3, 4}
var res []int
Chain(arr).Reject(func(n, i int) bool {
	return n%2 == 0
}).Value(&res)
// or
res := Reject(arr, func(n, i int) bool {
	return n%2 == 0
}).([]int)
// res = [1 3]

RejectBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• interface{} - an array of all the values that without pass a truth test properties

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(arr).RejectBy(map[string]interface{}{
	"Id": 1,
}).Value(&res)
// or
res := RejectBy(arr, map[string]interface{}{
	"Id": 1,
}).([]testModel)
// res = [{{0} 2 two} {{0} 3 three}]

Reverse(source, selector)

Arguments

• source - array or map
• selector - func(element, key or index) anyType

Return

• interface{} - an array of source that reversed

Examples

arr := []testModel{
	{ID: 2, Name: "two"},
	{ID: 1, Name: "one"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(arr).Reverse(func(n testModel, _ int) int {
	return n.ID
}).Value(&res)
// or
res := Reverse(arr, func(n testModel, _ int) int {
	return n.ID
}).([]testModel)
// res = [{{0} 3 three} {{0} 2 two} {{0} 1 one}]

ReverseBy(source, selector)

Arguments

• source - array or map
• property - string

Return

• interface{} - an array of source that reversed

Examples

arr := []testModel{
	{ID: 2, Name: "two"},
	{ID: 1, Name: "one"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(arr).ReverseBy("id").Value(&res)
// or
res := ReverseBy(arr, "id").([]testModel)
// res = [{{0} 3 three} {{0} 2 two} {{0} 1 one}]

Size(source)

Arguments

• source - array or map

Return

• int

Examples

dict := map[string]int{
	"a": 1,
	"b": 2,
	"c": 3,
}
l := Size(dict)
// l = 3

Sort(source, selector)

Arguments

• source - array or map
• selector - func(element, key or index) anyType

Return

• interface{} - an array of source that sorted

Examples

arr := []testModel{
	{ID: 2, Name: "two"},
	{ID: 1, Name: "one"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(arr).Sort(func(n testModel, _ int) int {
	return n.ID
}).Value(&res)
// or
res := Sort(arr, func(n testModel, _ int) int {
	return n.ID
}).([]testModel)
// res = [{{0} 1 one} {{0} 2 two} {{0} 3 three}]

SortBy(source, property)

Arguments

• source - array or map
• property - string

Return

• interface{}

Examples

arr := []testModel{
	{ID: 2, Name: "two"},
	{ID: 1, Name: "one"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(arr).SortBy("id").Value(&res)
// or
res := SortBy(arr, "id").([]testModel)
// res = [{{0} 1 one} {{0} 2 two} {{0} 3 three}]

Take(source, count)

Arguments

• source - array or map
• count - int

Return

• interface{}

Examples

arr := []int{1, 2, 3}
var res []int
Chain(arr).Take(1).Value(&res)
// or
res := Take(arr, 1).([]int)
// res = [1]

Uniq(source, selector)

Arguments

• source - array
• selector - nil or func(element or value, index or key) anyType

Return

• interface{} - only the first occurence of each value is kept

Examples

arr := []int{1, 2, 1, 4, 1, 3}
var res []int
Chain(arr).Uniq(func(n, _ int) int {
	return n % 2
}).Value(&res)
// or
res := Uniq(arr, func(n, _ int) int {
	return n % 2
}).([]int)
// res = [1 2]

UniqBy(source, property)

Arguments

• source - array
• property - string

Return

• interface{}

Examples

arr := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "one"},
	{ID: 3, Name: "one"},
}
var res []testModel
Chain(arr).UniqBy("name").Value(&res)
// or
res := UniqBy(arr, "Name").([]testModel)
// res = [{{0} 1 one}]

UUID()

Return

• string - uuid string

Examples

uuid := UUID()
//1a40272540e57d1c80e7b06042219d0c

Value(result)

Examples

arr := []int{1, 2, 1, 4, 1, 3}
var res map[string][]int
Chain(arr).Uniq(nil).Group(func(n, _ int) string {
	if n%2 == 0 {
		return "even"
	}

	return "old"
}).Value(&res)
// res = map[old:[1 3] even:[2 4]]

Values(source)

Arguments

• source - map

Return

• interface{} - an array of source's values

Examples

src := map[int]string{
	1: "a",
	2: "b",
	3: "c",
	4: "d",
}
var res []string
Chain(src).Values().Value(&res)
// or
res := Values(src).([]string)
// res = [a b c d]

Where(source, predicate)

Arguments

• source - array or map
• predicate - func(element or value, index or key) bool

Return

• interface{} - an array of all the values that pass a truth test predicate

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(src).Where(func(r testModel, i int) bool {
	return r.ID%2 == 0
}).Value(&res)
// or
res := Where(src, func(r testModel, i int) bool {
	return r.ID%2 == 0
}).([]testModel)
// res = [{{0} 2 two}]

WhereBy(source, properties)

Arguments

• source - array or map
• properties - map[string]interface{}

Return

• interface{} - an array of all the values that pass a truth test properties

Examples

src := []testModel{
	{ID: 1, Name: "one"},
	{ID: 2, Name: "two"},
	{ID: 3, Name: "three"},
}
var res []testModel
Chain(src).WhereBy(map[string]interface{}{
	"name": "one",
}).Value(&res)
// or
res := WhereBy(src, map[string]interface{}{
	"name": "one",
}).([]testModel
// res = [{{0} 1 one}]