仿 common-lang 包的 go 语言工具库

common-lang-in-go

https://github.com/sjsdfg/common-lang-in-go

Java 程序员编写的类似 common-lang 工具包
包名就是要用大驼峰，不想改成 go 规范的包名。自己写的任性

how to use

go get github.com/sjsdfg/common-lang-in-go

StringUtils

IsEmpty(str string) bool
IsNotEmpty(str string) bool
IsAllEmpty(list ...string) bool
IsAnyEmpty(list ...string) bool
IsAnyNoneEmpty(list ...string) bool
IsBlank(str string) bool
IsNotBlank(str string) bool
IsZero(str string) bool
IsNotZero(str string) bool
IsAnyZero(list ...string) bool
IsAllZero(list ...string) bool
IsAnyNoneZero(list ...string) bool
Equal(str1, str2 string) bool
EqualIgnoreCase(str1, str2 string) bool
EqualsAny(str string, list ...string) bool
EqualsAnyIgnoreCase(str string, list ...string) bool
IsDigital(str string) bool
DefaultIfEmpty(str, defaultStr string) string
If(condition bool, ifTrue, ifFalse string) string
Truncate(str string, startIndex, endIndex int) string

CollectionUtils

match functions

AllMatch(list interface{}, action matchFunc) bool
AnyMatch(list interface{}, action matchFunc) bool
NoneMatch(list interface{}, action matchFunc) bool

Use Case

func TestAllMatch(t *testing.T) {
    testCase := []string{"a", "a", "a"}
    assert.Equal(t, true, AllMatch(testCase, func(index int) bool {
        return testCase[index] == "a"
    }))

    testCase = []string{"a", "a", "b"}
    assert.Equal(t, false, AllMatch(testCase, func(index int) bool {
        return testCase[index] == "a"
    }))
}

func TestAnyMatch(t *testing.T) {
    testCase := []string{"a", "a", "b"}
    assert.Equal(t, true, AnyMatch(testCase, func(index int) bool {
        return testCase[index] == "b"
    }))

    testCase = []string{"a", "a", "b"}
    assert.Equal(t, false, AnyMatch(testCase, func(index int) bool {
        return testCase[index] == "c"
    }))
}

func TestNoneMatch(t *testing.T) {
    testCase := []string{"a", "a", "b"}
    assert.Equal(t, true, NoneMatch(testCase, func(index int) bool {
        return testCase[index] == "c"
    }))

    testCase = []string{"a", "a", "b"}
    assert.Equal(t, false, NoneMatch(testCase, func(index int) bool {
        return testCase[index] == "b"
    }))
}

empty judgement

IsEmpty(collection interface{})
IsNotEmpty(collection interface{}) bool

map function

这个是由于没有 Java Stream 里面的 map，导致每次提取某一类型的字段成为数组，写的代码十分冗余。所以抽象出来的。

由于不支持泛型，只能书写基本类型的方法调用。不过我的个人场景就是提取某一个字段（尤其是 id），目前还够用。

MapToStringSlice(list interface{}, action func(index int) string) []string
MapToIntSlice(list interface{}, action func(index int) int) []int
MapToInt64Slice(list interface{}, action func(index int) int64) []int64
MapToFloat64Slice(list interface{}, action func(index int) float64) []float64
MapToFloat32Slice(list interface{}, action func(index int) float32) []float32

Use Case

func TestMapToStringSlice(t *testing.T) {
    students := createStudents()
    timer := TimeUtils.NewTimer()
    reflectSlice := MapToStringSlice(students, func(i int) string {
        return students[i].name
    })
    t.Logf("MapToStringSlice cost %d nanos", timer.GetDurationInNanos())

    timer.Reset()
    nativeSlice := NativeMapToStringSlice(students)
    t.Logf("NativeMapToStringSlice cost %d nanos", timer.GetDurationInNanos())
    assert.Equal(t, nativeSlice, reflectSlice)
}

iterate

ForEach(list interface{}, action func(index int))：之前写 Java 写惯了，觉得使用 return 代替 continue 是可读性更高的代码，因为可以提早返回减少代码的嵌套接口。因此抽象出了该方法

func TestForEach(t *testing.T) {
    students := createStudents()
    ForEach(students, func(index int) {
        t.Log(students[index])
    })

    ForEach(students, func(index int) {
        students[index].name = "testing"
    })

    ForEach(students, func(index int) {
        assert.Equal(t, "testing", students[index].name)
    })
}

注意

以上方法类型为 FunctionName(list interface{}, action func(index int)) 均可以替换为 FunctionName(len int, action func(index int))

比如 ForEach 的实现可以为

func ForEach(len int, action func(i int)) {
    for i := 0; i < len; i++ {
        action(i)
    }
}

这个版本的运行效率更高。但是考虑到边界检查的安全性问题，我还是更倾向于传入 list 进来，通过反射来获取列表的长度。相关代码可查看 https://github.com/sjsdfg/common-lang-in-go/blob/faster/CollectionUtils/collection_utils.go

Float32Utils

Max(list ...float32) float32
Min(list ...float32) float32
If(condition bool, ifTrue, ifFalse float32) float32
Abs(a float32) float32
Equal(a, b float32) bool

Float64Utils

Max(list ...float64) float64
Min(list ...float64) float64
If(condition bool, ifTrue, ifFalse float64) float64
Abs(a float64) float64
Equal(a, b float64) bool

Int64Utils

Max(list ...int64) int64
Min(list ...int64) int64
If(condition bool, ifTrue, ifFalse int64) int64
Abs(a int64) int64

IntUtils

Max(list ...int) int
Min(list ...int) int
If(condition bool, ifTrue, ifFalse int64) int
Abs(a int) int

TimeUtils

Max(list ...time.Time) time.Time
Min(list ...time.Time) time.Time
If(condition bool, ifTrue, ifFalse int64) time.Time

上面的 XxxUtils 根据类型进行抽象，提供了最大值最小值的方法。并且因为 go 语言没有提供三目表达式，提供了 If 方法出来。可以边写出来可读性更高的代码

最佳实践

// 待实现
主要是想配合 IDEA 的 live template 和 Postfix completion 进行快捷键的搭配。

这样可以更好的使用该库。

Benchmark

CollectionUtils

CollectionUtils#IsEmpty

goos: darwin
goarch: amd64
pkg: github.com/sjsdfg/common-lang-in-go/CollectionUtils
BenchmarkIsEmpty                        22247214            54.3 ns/op
BenchmarkIsEmpty-2                      23466332            51.7 ns/op
BenchmarkIsEmpty-4                      23064122            51.4 ns/op
BenchmarkIsEmpty-8                      23634132            51.5 ns/op
BenchmarkNativeIsEmpty
BenchmarkNativeIsEmpty                  20717202            53.7 ns/op
BenchmarkNativeIsEmpty-2                23106975            50.9 ns/op
BenchmarkNativeIsEmpty-4                22869487            51.1 ns/op
BenchmarkNativeIsEmpty-8                23977856            51.1 ns/op
PASS

CollectionUtils#MapToStringSlice


BenchmarkMapToStringSlice
BenchmarkMapToStringSlice                4942840           292 ns/op
BenchmarkMapToStringSlice-2              4770552           263 ns/op
BenchmarkMapToStringSlice-4              4740819           302 ns/op
BenchmarkMapToStringSlice-8              5007906           238 ns/op
BenchmarkNativeMapToStringSlice
BenchmarkNativeMapToStringSlice         10728244           113 ns/op
BenchmarkNativeMapToStringSlice-2       10394302           113 ns/op
BenchmarkNativeMapToStringSlice-4       10965626           112 ns/op
BenchmarkNativeMapToStringSlice-8       10831770           113 ns/op
PASS