Go 语言中使用反射

反射是语言比较重要的特征，也是进阶级的技巧，适当使用反射，有时候事半功倍。

代码如下:

// Data Model
type Dish struct {
  Id  int
  Name string
  Origin string
  Query func()
}

创建实例如下：

shabushabu = Dish.new
shabushabu.instance_variables # => []
shabushabu.name = "Shabu-Shabu"
shabushabu.instance_variables # => ["@name"]
shabushabu.origin = "Japan"
shabushabu.instance_variables # => ["@name", "@origin"]

完整代码如下：

package main
import(
  "fmt"
  "reflect"
)
 
func main(){
  // iterate through the attributes of a Data Model instance
  for name, mtype := range attributes(&Dish{}) {
    fmt.Printf("Name: %s, Type %s\n", name, mtype.Name())
  }
}
 
// Data Model
type Dish struct {
  Id  int
  Name string
  Origin string
  Query func()
}
 
// Example of how to use Go's reflection
// Print the attributes of a Data Model
func attributes(m interface{}) (map[string]reflect.Type) {
  typ := reflect.TypeOf(m)
  // if a pointer to a struct is passed, get the type of the dereferenced object
  if typ.Kind() == reflect.Ptr{
    typ = typ.Elem()
  }
 
  // create an attribute data structure as a map of types keyed by a string.
  attrs := make(map[string]reflect.Type)
  // Only structs are supported so return an empty result if the passed object
  // isn't a struct
  if typ.Kind() != reflect.Struct {
    fmt.Printf("%v type can't have attributes inspected\n", typ.Kind())
    return attrs
  }
 
  // loop through the struct's fields and set the map
  for i := 0; i < typ.NumField(); i++ {
    p := typ.Field(i)
      if !p.Anonymous {
        attrs[p.Name] = p.Type
      }
     }
  return attrs
}