duan0414 2017-03-20 10:05
浏览 72
已采纳

Golang:如何在切片之间附加指针?

I'm a Golang newbie but I thought I had got the essentials of pointers and references straight, but apparently not:

I have a method that must return a []github.Repository, which is a type from the Github client in go.

The API call returns the results paginated so I must cycle until there's no more results, and add the result of each call to the allRepos variable, and return that. Here's what I have so far:

func (s *inmemService) GetWatchedRepos(ctx context.Context, username string) ([]github.Repository, error) {
    s.mtx.RLock()
    defer s.mtx.RUnlock()

    opt := &github.ListOptions{PerPage: 20}

    var allRepos []github.Repository

    for {
        // repos is of type *[]github.Repository
        repos, resp, err := s.ghClient.Activity.ListWatched(ctx, "", opt)

        if err != nil {
            return []github.Repository{}, err
        }

        // ERROR: Cannot use repos (type []*github.Repository) as type github.Repository
        // but dereferencing it doesn't work, either
        allRepos = append(allRepos, repos...)
        if resp.NextPage == 0 {
            break
        }
        opt.Page = resp.NextPage
    }

    return allRepos, nil

}

My question: how can I append the results of each call and return a result of type []github.Repository?

Also, why doesn't dereferencing work here? I've tried replacing allRepos = append(allRepos, repos...) with allRepos = append(allRepos, *(repos)...) but I get this error message:

Invalid indirect of (repos) (type []*github.Repository)
  • 写回答

2条回答 默认 最新

  • doomm4711 2017-03-20 10:16
    关注

    Well, something is not okay here:

    You say in the comment that "repos is of type *[]github.Repository" but the compiler's error message indicates that repos is of type []*Repository". The compiler is never (except when buggy) wrong.

    Note that *[]github.Repository and []*Repository are completely different types, especially the second is not a slice of Repositories and you cannot (really, there is no way) dereference these pointers during append(): You have to write a loop and dereference each slice item and append one by one.

    What is strange too: github.Repository and Repository seem to be two different types one from package github, the other from the current package. Again, you'll have to get that straight too.

    Note that there are no references in Go. Stop thinking about these immediately: This is a concept from other languages which is not helpful (as inexistent) in Go.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 C++ /QT 内存权限的判断函数列举
  • ¥15 深度学习GFnet理解问题
  • ¥15 单细胞小提琴堆叠图代码
  • ¥80 LS dyna mpp并行报错
  • ¥50 升级strust2版本到2.3.15.1后使用ognl3.0.6.jar windows环境中没有问题,但部署到linux环境报错
  • ¥15 vue页面,node封装接口
  • ¥15 求TMS320F280039C工程模板!
  • ¥15 delphi+fastreport实现分组补空打印问题
  • ¥15 使用python把两台mysql数据库服务器数据导出和导入
  • ¥15 NodeBB论坛配置Apache Solr中文搜索引擎的详细教程