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

Thanks

Licenses for Open Source Development

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