来自自定义结构的Golang参考列表

Question

I have the following block of code:

package main

import (
    "fmt"
    "container/list"
)

type Foo struct {
    foo list  //want a reference to the list implementation   
             //supplied by the language
}


func main() {
   //empty  

}

When compiling I receive the following message:

use of package list not in selector

My question is, how do I reference list within a struct? Or is this not the proper idiom in Go for wrapping structures. (Composition)

Answer 1

I can see two problems:

1. importing the fmt package without using it. In Go unused imports result in compile-time errors;
2. foo is not declared correctly: list is a package name not a type; you want to use a type from the container/list package.

Corrected code:

package main

import (
    "container/list"
)

type Foo struct {
    // list.List represents a doubly linked list.
    // The zero value for list.List is an empty list ready to use.
    foo list.List
}

func main() {}

You can execute the above code in the Go Playground.
You should also consider reading the official documentation of the container/list package.

Depending on what you're trying to do, you might also want to know that Go allows you to embed types within a struct or interface. Read more in the Effective Go guide and decide wether or not this makes sense for your particular case.