%s
` var pageTop = "" var pageBottom = "" func main() { http.HandleFunc("/", homePage) if err := http.ListenAndServe(":9001", nil); err != nil { log.Fatal("failed to start server", err) } } func homePage(writer http.ResponseWriter, request *http.Request) { writer.Header().Set("Content-Type", "text/html") err := request.ParseForm() // Must be called before writing response fmt.Fprint(writer, pageTop, form) if err != nil { fmt.Fprintf(writer, error, err) } else { if numbers, message, ok := processRequest(request); ok { stats := getStats(numbers) fmt.Fprint(writer, formatStats(stats)) } else if message != "" { fmt.Fprintf(writer, error, message) } } fmt.Fprint(writer, pageBottom) } func processRequest(request *http.Request) ([]float64, string, bool) { var numbers []float64 if slice, found := request.Form["numbers"]; found && len(slice) > 0 { text := strings.Replace(slice[0], ",", " ", -1) for _, field := range strings.Fields(text) { if x, err := strconv.ParseFloat(field, 64); err != nil { return numbers, "'" + field + "' is invalid", false } else { numbers = append(numbers, x) } } } if len(numbers) == 0 { return numbers, "", false // no data first time form is shown } return numbers, "", true } func getStats(numbers []float64) (stats statistics) { stats.numbers = numbers sort.Float64s(stats.numbers) stats.mean = sum(numbers) / float64(len(numbers)) stats.median = median(numbers) return } func sum(numbers []float64) (total float64) { for _, x := range numbers { total += x } return } func median(numbers []float64) float64 { middle := len(numbers)/2 result := numbers[middle] if len(numbers)%2 == 0 { result = (result + numbers[middle-1]) / 2 } return result } func formatStats(stats statistics) string { return fmt.Sprintf(`| Results | |
|---|---|
| Numbers | %v |
| Count | %d |
| Mean | %f |
| Median | %f |