帮忙看看这代码吧

代码在这里下载http://yunpan.cn/QNwGTz2VArLCq 这里也可以下载https://gist.github.com/rowland/984989

Go http client with cookie support 代码的功能

type HttpClient struct {
    client   http.Client
    jar      CookieJar
    Log      io.Writer
    patterns map[*regexp.Regexp]func(matches []string)
}

上面的这个patterns有什么作用?

func (this *HttpClient) invokeCallbacks(url string) {
    for re, cb := range this.patterns {
        fmt.Printf("Examining %s...\n", re)
        matches := re.FindStringSubmatch(url)
        if matches != nil {
            fmt.Printf("Executing callback for %s...\n", re)
            cb(matches)
        }
    }
}

这个函数是怎么执行的?

func (this *HttpClient) Match(pattern string, callback func(matches []string)) {
    if this.patterns == nil {
        this.patterns = make(map[*regexp.Regexp]func(matches []string))
    }
    re := regexp.MustCompile(ExpandRegex(pattern))
    this.patterns[re] = callback
}

这个函数没看明白,用到哪里了?