什么是locationName标记，如何使用？

Question

I was going over the go SDK for aws ec2. I don't understand why almost all the structs in the SDK have this tag :`locationName'

For Example type DescribeInstancesOutput struct {

// The token to use to retrieve the next page of results. This value is null
// when there are no more results to return.
NextToken *string `locationName:"nextToken" type:"string"`

// Zero or more reservations.
Reservations []*Reservation `***locationName***:"reservationSet" locationNameList:"item" type:"list"`
// contains filtered or unexported fields

} Does anyone know the purpose of the tags?

Source - https://docs.aws.amazon.com/sdk-for-go/api/service/ec2/#DescribeInstancesOutput

Answer 1

From searching the source code, it appears it's used with internal json/xml parsing/encoding. This is similar to the way that the json tag is used by encoding/json.

This answer goes into pretty good depth on tags in go.

They can be accessed/used with the reflect package.