code review 5307066: non-pkg: gofix -r error

doc/codelab/wiki/final-parsetemplate.go

 package main
 
 import (
         "http"
         "io/ioutil"
-        "os"
         "regexp"
         "template"
 )
 
 type Page struct {
         Title string
         Body  []byte
 }
 
-func (p *Page) save() os.Error {
+func (p *Page) save() error {
         filename := p.Title + ".txt"
         return ioutil.WriteFile(filename, p.Body, 0600)
 }
 
-func loadPage(title string) (*Page, os.Error) {
+func loadPage(title string) (*Page, error) {
         filename := title + ".txt"
         body, err := ioutil.ReadFile(filename)
         if err != nil {
                 return nil, err
         }
         return &Page{Title: title, Body: body}, nil
 }
 
 func viewHandler(w http.ResponseWriter, r *http.Request, title string) {
         p, err := loadPage(title)
@@ skipping 10 matching lines @@
                 p = &Page{Title: title}
         }
         renderTemplate(w, "edit", p)
 }
 
 func saveHandler(w http.ResponseWriter, r *http.Request, title string) {
         body := r.FormValue("body")
         p := &Page{Title: title, Body: []byte(body)}
         err := p.save()
         if err != nil {
-                http.Error(w, err.String(), http.StatusInternalServerError)
+                http.Error(w, err.Error(), http.StatusInternalServerError)
                 return
         }
         http.Redirect(w, r, "/view/"+title, http.StatusFound)
 }
 
 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
         t, err := template.ParseFile(tmpl+".html", nil)
         if err != nil {
-                http.Error(w, err.String(), http.StatusInternalServerError)
+                http.Error(w, err.Error(), http.StatusInternalServerError)
                 return
         }
         err = t.Execute(w, p)
         if err != nil {
-                http.Error(w, err.String(), http.StatusInternalServerError)
+                http.Error(w, err.Error(), http.StatusInternalServerError)
         }
 }
 
 const lenPath = len("/view/")
 
 var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
 
 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
         return func(w http.ResponseWriter, r *http.Request) {
                 title := r.URL.Path[lenPath:]
                 if !titleValidator.MatchString(title) {
                         http.NotFound(w, r)
                         return
                 }
                 fn(w, r, title)
         }
 }
 
 func main() {
         http.HandleFunc("/view/", makeHandler(viewHandler))
         http.HandleFunc("/edit/", makeHandler(editHandler))
         http.HandleFunc("/save/", makeHandler(saveHandler))
         http.ListenAndServe(":8080", nil)
 }