improve error handling

cmdparse/lexer.go

@@ -35,9 +35,6 @@ const (
 	End
 	Whitespace
 
-	number
-	letter
-	ws
 	illegal
 )
 
@@ -159,7 +156,3 @@ func isLetter(ch rune) bool {
 func isDigit(ch rune) bool {
 	return ch >= '0' && ch <= '9'
 }
-
-func isEOF(ch rune) bool {
-	return ch == rune(0)
-}

config/lexer.go

@@ -194,7 +194,3 @@ func isWhitespace(ch rune) bool {
 func isText(ch rune) bool {
 	return ch >= '!' && ch <= '~' && ch != equal && ch != l_brace && ch != r_brace
 }
-
-func isEOF(ch rune) bool {
-	return ch == eof
-}

config/parser.go

@@ -86,7 +86,10 @@ func (p *Parser) Parse() (Config, error) {
 			}
 			switch section {
 			case "BOOKMARKS":
-				c.Bookmarks.Add([]string{keyval.Value, keyval.Key})
+				err := c.Bookmarks.Add([]string{keyval.Value, keyval.Key})
+				if err != nil {
+					return c, err
+				}
 			case "COLORS":
 				c.Colors = append(c.Colors, keyval)
 			case "SETTINGS":

cui/cui.go

@@ -57,7 +57,11 @@ func moveCursorToward(dir string, amount int) {
 func Exit() {
 	moveCursorToward("down", 500)
 	moveCursorToward("right", 500)
-	SetLineMode()
+	err := SetLineMode()
+	if err != nil {
+		panic(err)
+	}
+
 	fmt.Print("\n")
 	fmt.Print("\033[?25h")
 	os.Exit(0)
@@ -79,7 +83,7 @@ func Clear(dir string) {
 
 }
 
-func WrapLines(s []string, length int) []string {
+func wrapLines(s []string, length int) []string {
 	out := []string{}
 	for _, ln := range s {
 		if len(ln) <= length {
@@ -121,26 +125,43 @@ func Getch() rune {
 	return char
 }
 
-func GetLine() string {
-	SetLineMode()
-	reader := bufio.NewReader(os.Stdin)
-	fmt.Print(": ")
-	text, _ := reader.ReadString('\n')
-	SetCharMode()
-	return text[:len(text)-1]
+func GetLine() (string, error) {
+	err := SetLineMode()
+	if err != nil {
+		return "", err
 	}
 
-func SetCharMode() {
+	reader := bufio.NewReader(os.Stdin)
+	fmt.Print(": ")
+	text, err := reader.ReadString('\n')
+	if err != nil {
+		return "", err
+	}
+
+	err = SetCharMode()
+	if err != nil {
+		return "", err
+	}
+
+	return text[:len(text)-1], nil
+}
+
+func SetCharMode() error {
 	cmd := exec.Command("stty", "cbreak", "-echo")
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
-	cmd.Run()
-	fmt.Print("\033[?25l")
+	err := cmd.Run()
+	if err != nil {
+		return err
 	}
 
-func SetLineMode() {
+	_, err = fmt.Print("\033[?25l")
+	return err
+}
+
+func SetLineMode() error {
 	cmd := exec.Command("stty", "-cbreak", "echo")
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
-	cmd.Run()
+	return cmd.Run()
 }

cui/screen.go

@@ -142,7 +142,7 @@ func (s *Screen) GetSize() {
 
 // NewScreen is a constructor function that returns a pointer
 // to a Screen struct
-func NewScreen() *Screen {
+func NewScreen() (*Screen, error) {
 	if screenInit {
 		fmt.Println("Fatal error: Cannot create multiple screens")
 		os.Exit(1)
@@ -152,8 +152,12 @@ func NewScreen() *Screen {
 	for i := 0; i < s.Height; i++ {
 		fmt.Println()
 	}
-	SetCharMode()
+	err := SetCharMode()
+	if err != nil {
+		return nil, err
+	}
+
 	Clear("screen")
 	screenInit = true
-	return &s
+	return &s, nil
 }

cui/window.go

@@ -64,7 +64,7 @@ func (w *Window) DrawContent() {
 	height := w.Box.row2 - w.Box.row1 + borderThickness
 	width := w.Box.col2 - w.Box.col1 + borderThickness
 
-	content := WrapLines(w.Content, width)
+	content := wrapLines(w.Content, width)
 
 	if len(content) < w.Scrollposition+height {
 		maxlines = len(content)

gopher/url.go

@@ -33,7 +33,7 @@ func MakeUrl(u string) (Url, error) {
 	re := regexp.MustCompile(`^((?P<scheme>gopher|http|https|ftp|telnet):\/\/)?(?P<host>[\w\-\.\d]+)(?::(?P<port>\d+)?)?(?:/(?P<type>[01345679gIhisp])?)?(?P<resource>(?:[\/|Uu].*)?)?$`)
 	match := re.FindStringSubmatch(u)
 
-	if valid := re.MatchString(u); valid != true {
+	if valid := re.MatchString(u); !valid {
 		return out, errors.New("Invalid URL or command character")
 	}
 

main.go

@@ -27,11 +27,6 @@ var options = map[string]string{
 	"httpbrowser":  "lynx",
 }
 
-func errExit(err string, code int) {
-	fmt.Println(err)
-	os.Exit(code)
-}
-
 func saveFile(address, name string) error {
 	quickMessage("Saving file...", false)
 	defer quickMessage("Saving file...", true)
@@ -73,7 +68,12 @@ func search(u string) error {
 	cui.Clear("line")
 	fmt.Print("Enter form input: ")
 	cui.MoveCursorTo(screen.Height-1, 17)
-	entry := cui.GetLine()
+
+	entry, err := cui.GetLine()
+	if err != nil {
+		return err
+	}
+
 	quickMessage("Searching...", false)
 	searchurl := fmt.Sprintf("%s\t%s", u, entry)
 	sv, err := gopher.Visit(searchurl, options["openhttp"])
@@ -126,9 +126,6 @@ func toggleBookmarks() {
 		bookmarks.Active = true
 	}
 
-	if screen.Activewindow == 0 {
-	} else {
-	}
 	screen.ReflashScreen(false)
 }
 
@@ -230,10 +227,18 @@ func doLinkCommand(action, target string) error {
 	switch action {
 	case "DELETE", "D":
 		err := settings.Bookmarks.Del(num)
-		screen.Windows[1].Content = settings.Bookmarks.List()
-		saveConfig()
-		screen.ReflashScreen(false)
+		if err != nil {
 			return err
+		}
+
+		screen.Windows[1].Content = settings.Bookmarks.List()
+		err = saveConfig()
+		if err != nil {
+			return err
+		}
+
+		screen.ReflashScreen(false)
+		return nil
 	case "BOOKMARKS", "B":
 		if num > len(settings.Bookmarks.Links)-1 {
 			return fmt.Errorf("There is no bookmark with ID %d", num)
@@ -260,8 +265,13 @@ func doCommandAs(action string, values []string) error {
 		if err != nil {
 			return err
 		}
+
 		screen.Windows[1].Content = settings.Bookmarks.List()
-		saveConfig()
+		err = saveConfig()
+		if err != nil {
+			return err
+		}
+
 		screen.ReflashScreen(false)
 		return nil
 	case "WRITE", "W":
@@ -269,8 +279,7 @@ func doCommandAs(action string, values []string) error {
 	case "SET", "S":
 		if _, ok := options[values[0]]; ok {
 			options[values[0]] = strings.Join(values[1:], " ")
-			saveConfig()
-			return nil
+			return saveConfig()
 		}
 		return fmt.Errorf("Unable to set %s, it does not exist", values[0])
 	}
@@ -295,8 +304,14 @@ func doLinkCommandAs(action, target string, values []string) error {
 		if err != nil {
 			return err
 		}
+
 		screen.Windows[1].Content = settings.Bookmarks.List()
-		saveConfig()
+
+		err = saveConfig()
+		if err != nil {
+			return err
+		}
+
 		screen.ReflashScreen(false)
 		return nil
 	case "WRITE", "W":
@@ -329,7 +344,7 @@ func quickMessage(msg string, clearMsg bool) {
 	}
 }
 
-func saveConfig() {
+func saveConfig() error {
 	bkmrks := settings.Bookmarks.IniDump()
 	opts := "\n[SETTINGS]\n"
 	for k, v := range options {
@@ -338,14 +353,19 @@ func saveConfig() {
 		opts += v
 		opts += "\n"
 	}
-	ioutil.WriteFile(userinfo.HomeDir+"/.bombadillo.ini", []byte(bkmrks+opts), 0644)
+
+	return ioutil.WriteFile(userinfo.HomeDir+"/.bombadillo.ini", []byte(bkmrks+opts), 0644)
 }
 
-func loadConfig() {
+func loadConfig() error {
 	file, err := os.Open(userinfo.HomeDir + "/.bombadillo.ini")
 	if err != nil {
-		saveConfig()
+		err = saveConfig()
+		if err != nil {
+			return err
 		}
+	}
+
 	confparser := config.NewParser(file)
 	settings, _ = confparser.Parse()
 	file.Close()
@@ -356,6 +376,8 @@ func loadConfig() {
 			options[lowerkey] = v.Value
 		}
 	}
+
+	return nil
 }
 
 func toggleActiveWindow() {
@@ -378,10 +400,20 @@ func displayError(err error) {
 	fmt.Print("\033[41m\033[37m", err, "\033[0m")
 }
 
-func initClient() {
+func initClient() error {
 	history.Position = -1
-	screen = cui.NewScreen()
-	cui.SetCharMode()
+
+	var err error
+	screen, err = cui.NewScreen()
+	if err != nil {
+		return err
+	}
+
+	err = cui.SetCharMode()
+	if err != nil {
+		return err
+	}
+
 	screen.AddWindow(2, 1, screen.Height-2, screen.Width, false, false, true)
 	screen.Windows[0].Active = true
 	screen.AddMsgBar(1, "  ((( Bombadillo )))  ", "  A fun gopher client!", true)
@@ -390,12 +422,18 @@ func initClient() {
 		bookmarksWidth = screen.Width
 	}
 	screen.AddWindow(2, screen.Width-bookmarksWidth, screen.Height-2, screen.Width, false, true, false)
-	loadConfig()
+	return loadConfig()
 }
 
 func main() {
 	defer cui.Exit()
-	initClient()
+	err := initClient()
+	if err != nil {
+		// if we can't initialize the window,
+		// we can't do anything!
+		panic(err)
+	}
+
 	mainWindow := screen.Windows[0]
 	firstLoad := true
 
@@ -440,7 +478,11 @@ func main() {
 			toggleActiveWindow()
 		case ':', ' ':
 			cui.MoveCursorTo(screen.Height-1, 0)
-			entry := cui.GetLine()
+			entry, err := cui.GetLine()
+			if err != nil {
+				displayError(err)
+			}
+
 			// Clear entry line and error line
 			clearInput(true)
 			if entry == "" {