Merge pull request #2 from golang-infrastructure/dev

Dev

Author: CC11001100

README.md

@@ -1,5 +1,7 @@
 # Go Pointer
 
+[中文文档](./README.md) [English Document](./README_en.md)
+
 # 一、引入依赖
 
 ```text

README_en.md

@@ -0,0 +1,89 @@
+# Go Pointer
+
+[中文文档](./README.md) [English Document](./README_en.md)
+
+# 1. Use go get install it
+
+```text
+go get -u github.com/golang-infrastructure/go-pointer
+```
+
+# 2. What problem was solved
+
+In golang, the primitive type has no wrapping type, so the primitive type can't distinguish between nil and zero,
+so many libraries tend to use Pointers to primitive variables to distinguish between zero and not passed.
+
+For a specific example, when no Pointers are used, there is a configuration item when executing a task:
+
+```go
+package main
+
+type Config struct {
+	Foo int
+}
+
+```
+
+When Foo is 0, we do not know whether we have passed zero or no value, because some libraries prefer to use pointer
+types in this case:
+
+```go
+package main
+
+type Config struct {
+	Foo *int
+}
+
+```
+
+However, sometimes this value is passed in as a literal constant, such as the paging size when querying a database. In
+this case,
+getting a pointer type can be a bit of a hassle. The above scenario is just an example of a problem that this module is
+designed to solve.
+
+# 3. Example Code
+
+Generics are already supported:
+
+```go
+package main
+
+import (
+	"fmt"
+	pointer "github.com/golang-infrastructure/go-reflect-utils"
+)
+
+func main() {
+
+	// Returns a pointer to false
+	falsePointer := pointer.FalsePointer()
+	fmt.Println(fmt.Sprintf("%T %v", falsePointer, *falsePointer)) // Output: *bool false
+
+	// Returns a pointer to true
+	truePointer := pointer.TruePointer()
+	fmt.Println(fmt.Sprintf("%T %v", truePointer, *truePointer)) // Output: *bool true
+
+	// Returns a pointer to the corresponding type
+	v1 := 1
+	toPointer := pointer.ToPointer(v1)
+	fmt.Println(fmt.Sprintf("%T %v", toPointer, *toPointer)) // Output: *int 1
+	// Returns a pointer to the corresponding type, but checks the value and returns nil if the value is zero of the corresponding type
+	v1 = 0
+	orNil := pointer.ToPointerOrNil(v1)
+	fmt.Println(orNil) // Output: nil
+
+	// Reads a value from a pointer, and returns a zero value of the corresponding type if it is a nil pointer
+	v2 := 1
+	v3 := &v2
+	fromPointer := pointer.FromPointer(v3)
+	fmt.Println(fromPointer) // Output: 1
+	// Reads the value from a pointer, and returns the given default value if it is a nil pointer
+	v2 = 0
+	orDefault := pointer.FromPointerOrDefault(v3, 1)
+	fmt.Println(orDefault) // Output: 0
+}
+```
+
+
+
+