无法列出。

Take a look at the following source code:

import "container/list"

type Stream struct {
    list list.List
}

func (s Stream) Append(value interface{}) {
    log.Println(s.list.Len())
    s.list.PushBack(value)
    log.Println(s.list.Len())
}

This code will keep on printing 0 and 1 all the time. Am I doing it wrong?

You're copying your Stream and List values in the Append method.

Either make Append a pointer receiver

func (s *Stream) Append(value interface{}) {

or make Stream.list a *list.List

type Stream struct {
    list *list.List
}