Gophercises - 5 - Sitemap Builder

Problem

• https://github.com/gophercises/sitemap
• https://gophercises.com/exercises/sitemap

Solutions

• Normal-Bonus: Normal and bonus. Works and has depth. Can log to file

  $ go run main.go sitemap.go --help
  -depth int
          specify sitemap depth (default 2147483647)
  -file string
          name of xml file
  -log
          display logs
  -url string
          staring URL - must be provided
  

Lessons Learned

net.URL

• https://golang.org/pkg/net/url/
• There are tons of great methods.
• Convert a string to URL: Parse(rawurl string) (*URL, error)
• URL will give you tons of utilities:

  type URL struct {
      Scheme     string
      Opaque     string    // encoded opaque data
      User       *Userinfo // username and password information
      Host       string    // host or host:port
      Path       string    // path (relative paths may omit leading slash)
      RawPath    string    // encoded path hint (see EscapedPath method)
      ForceQuery bool      // append a query ('?') even if RawQuery is empty
      RawQuery   string    // encoded query values, without '?'
      Fragment   string    // fragment for references, without '#'
  }
  

• IsAbs() returns true if path is absolute.
• Hostname() returns host and port.
• Contents are case-sensitive.
• Get the complete URL with URL.String().

ioutil.Discard

• var Discard io.Writer = devNull(0)

Break/Continue to Label

• Really helps when inside a select which is inside an infinite loop.
• Designate labels as usual.
• break or continue to label.

  Mainloop:
    for {
    	select {
    	case whatever:
    		//
    	default:
    		// Do what you want
    		break Mainloop
    	}
    }