仿 common-lang 包的 go 语言工具库

r囧r小猫 2022-12-05 10:10 34阅读 0赞

## common-lang-in-go ##

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

[![API Reference][]][API Reference 1]  
[![Go Report Card][]][Go Report Card 1]

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

[API Reference]: /images/20221123/d9200f9a32184baeb7f80a749c16255a.png
[API Reference 1]: https://pkg.go.dev/github.com/sjsdfg/common-lang-in-go
[Go Report Card]: /images/20221123/16f5534088d94d7c83dca9dcc5f713af.png
[Go Report Card 1]: https://goreportcard.com/report/github.com/sjsdfg/common-lang-in-go