Refactor option parser

1 files changed, 177 insertions, 352 deletions

diff --git a/src/options.go b/src/options.go
index 12861b03..11731b7c 100644
--- a/src/options.go
+++ b/src/options.go
@@ -700,54 +700,11 @@ func defaultOptions() *Options {
 		Version:      false}
 }
 
-func optString(arg string, prefixes ...string) (bool, string) {
-	for _, prefix := range prefixes {
-		if strings.HasPrefix(arg, prefix) {
-			return true, arg[len(prefix):]
-		}
-	}
-	return false, ""
-}
-
-func nextString(args []string, i *int, message string) (string, error) {
-	if len(args) > *i+1 {
-		*i++
-	} else {
-		return "", errors.New(message)
-	}
-	return args[*i], nil
-}
-
-func optionalNextString(args []string, i *int) (bool, string) {
-	if len(args) > *i+1 && !strings.HasPrefix(args[*i+1], "-") && !strings.HasPrefix(args[*i+1], "+") {
-		*i++
-		return true, args[*i]
-	}
-	return false, ""
-}
-
 func isDir(path string) bool {
 	stat, err := os.Stat(path)
 	return err == nil && stat.IsDir()
 }
 
-func nextDirs(args []string, i *int) ([]string, error) {
-	dirs := []string{}
-	for *i < len(args)-1 {
-		arg := args[*i+1]
-		if isDir(arg) {
-			dirs = append(dirs, arg)
-			*i++
-		} else {
-			break
-		}
-	}
-	if len(dirs) == 0 {
-		return nil, errors.New("no directory specified")
-	}
-	return dirs, nil
-}
-
 func atoi(str string) (int, error) {
 	num, err := strconv.Atoi(str)
 	if err != nil {
@@ -764,33 +721,6 @@ func atof(str string) (float64, error) {
 	return num, nil
 }
 
-func nextInt(args []string, i *int, message string) (int, error) {
-	if len(args) > *i+1 {
-		*i++
-	} else {
-		return 0, errors.New(message)
-	}
-	n, err := atoi(args[*i])
-	if err != nil {
-		return 0, errors.New(message)
-	}
-	return n, nil
-}
-
-func optionalNumeric(args []string, i *int, defaultValue int) (int, error) {
-	if len(args) > *i+1 {
-		if strings.IndexAny(args[*i+1], "0123456789") == 0 {
-			*i++
-			n, err := atoi(args[*i])
-			if err != nil {
-				return 0, err
-			}
-			return n, nil
-		}
-	}
-	return defaultValue, nil
-}
-
 func splitNth(str string) ([]Range, error) {
 	if match, _ := regexp.MatchString("^[0-9,-.]+$", str); !match {
 		return nil, errors.New("invalid format: " + str)
@@ -2077,6 +2007,13 @@ func parseMarkerMultiLine(str string) (*[3]string, error) {
 	return &result, nil
 }
 
+func optString(arg string, prefix string) (bool, string) {
+	if strings.HasPrefix(arg, prefix) {
+		return true, arg[len(prefix):]
+	}
+	return false, ""
+}
+
 func parseOptions(index *int, opts *Options, allArgs []string) error {
 	var err error
 	var historyMax int
@@ -2113,10 +2050,101 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		opts.Version = false
 		opts.Man = false
 	}
+
 	startIndex := *index
-	for i := 0; i < len(allArgs); i++ {
+
+	var i int
+	var val *string = nil
+	nextString := func(message string) (string, error) {
+		defer func() { val = nil }()
+		if val != nil {
+			return *val, nil
+		}
+		if len(allArgs) > i+1 {
+			i++
+		} else {
+			return "", errors.New(message)
+		}
+		return allArgs[i], nil
+	}
+
+	optionalNextString := func() (bool, string) {
+		defer func() { val = nil }()
+		if val != nil {
+			return true, *val
+		}
+		if len(allArgs) > i+1 && !strings.HasPrefix(allArgs[i+1], "-") && !strings.HasPrefix(allArgs[i+1], "+") {
+			i++
+			return true, allArgs[i]
+		}
+		return false, ""
+	}
+
+	nextDirs := func() ([]string, error) {
+		defer func() { val = nil }()
+		dirs := []string{}
+		if val != nil {
+			dirs = append(dirs, *val)
+		}
+		for i < len(allArgs)-1 {
+			arg := allArgs[i+1]
+			if isDir(arg) {
+				dirs = append(dirs, arg)
+				i++
+			} else {
+				break
+			}
+		}
+		if len(dirs) == 0 {
+			return nil, errors.New("no directory specified")
+		}
+		return dirs, nil
+	}
+
+	nextInt := func(message string) (int, error) {
+		defer func() { val = nil }()
+		var str string
+		if val != nil {
+			str = *val
+		} else if len(allArgs) > i+1 {
+			i++
+			str = allArgs[i]
+		} else {
+			return 0, errors.New(message)
+		}
+		n, err := atoi(str)
+		if err != nil {
+			return 0, errors.New(message)
+		}
+		return n, nil
+	}
+
+	optionalNumeric := func(defaultValue int) (int, error) {
+		defer func() { val = nil }()
+		var str string
+		if val != nil {
+			str = *val
+		} else if len(allArgs) > i+1 && strings.IndexAny(allArgs[i+1], "0123456789") == 0 {
+			i++
+			str = allArgs[i]
+		} else {
+			return defaultValue, nil
+		}
+		n, err := atoi(str)
+		if err != nil {
+			return 0, err
+		}
+		return n, nil
+	}
+
+	for ; i < len(allArgs); i++ {
 		arg := allArgs[i]
 		index := i + startIndex
+		if strings.HasPrefix(arg, "--") && strings.IndexRune(arg, '=') > 0 {
+			tokens := strings.SplitN(arg, "=", 2)
+			arg = tokens[0]
+			val = &tokens[1]
+		}
 		switch arg {
 		case "--man":
 			clearExitingOpts()
@@ -2139,7 +2167,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-winpty":
 			opts.NoWinpty = true
 		case "--tmux":
-			given, str := optionalNextString(allArgs, &i)
+			given, str := optionalNextString()
 			if given {
 				if opts.Tmux, err = parseTmuxOptions(str, index); err != nil {
 					return err
@@ -2156,7 +2184,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-force-tty-in":
 			opts.ForceTtyIn = false
 		case "--proxy-script":
-			if opts.ProxyScript, err = nextString(allArgs, &i, ""); err != nil {
+			if opts.ProxyScript, err = nextString(""); err != nil {
 				return err
 			}
 		case "-x", "--extended":
@@ -2172,11 +2200,11 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "+e", "--no-exact":
 			opts.Fuzzy = true
 		case "-q", "--query":
-			if opts.Query, err = nextString(allArgs, &i, "query string required"); err != nil {
+			if opts.Query, err = nextString("query string required"); err != nil {
 				return err
 			}
 		case "-f", "--filter":
-			filter, err := nextString(allArgs, &i, "query string required")
+			filter, err := nextString("query string required")
 			if err != nil {
 				return err
 			}
@@ -2186,7 +2214,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-literal":
 			opts.Normalize = true
 		case "--algo":
-			str, err := nextString(allArgs, &i, "algorithm required (v1|v2)")
+			str, err := nextString("algorithm required (v1|v2)")
 			if err != nil {
 				return err
 			}
@@ -2194,13 +2222,13 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--scheme":
-			str, err := nextString(allArgs, &i, "scoring scheme required (default|path|history)")
+			str, err := nextString("scoring scheme required (default|path|history)")
 			if err != nil {
 				return err
 			}
 			opts.Scheme = strings.ToLower(str)
 		case "--expect":
-			str, err := nextString(allArgs, &i, "key names required")
+			str, err := nextString("key names required")
 			if err != nil {
 				return err
 			}
@@ -2218,7 +2246,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--disabled", "--phony":
 			opts.Phony = true
 		case "--tiebreak":
-			str, err := nextString(allArgs, &i, "sort criterion required")
+			str, err := nextString("sort criterion required")
 			if err != nil {
 				return err
 			}
@@ -2226,7 +2254,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--bind":
-			str, err := nextString(allArgs, &i, "bind expression required")
+			str, err := nextString("bind expression required")
 			if err != nil {
 				return err
 			}
@@ -2234,7 +2262,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--color":
-			_, spec := optionalNextString(allArgs, &i)
+			_, spec := optionalNextString()
 			if len(spec) == 0 {
 				opts.Theme = tui.EmptyTheme()
 			} else {
@@ -2243,7 +2271,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				}
 			}
 		case "--toggle-sort":
-			str, err := nextString(allArgs, &i, "key name required")
+			str, err := nextString("key name required")
 			if err != nil {
 				return err
 			}
@@ -2251,13 +2279,13 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "-d", "--delimiter":
-			str, err := nextString(allArgs, &i, "delimiter required")
+			str, err := nextString("delimiter required")
 			if err != nil {
 				return err
 			}
 			opts.Delimiter = delimiterRegexp(str)
 		case "-n", "--nth":
-			str, err := nextString(allArgs, &i, "nth expression required")
+			str, err := nextString("nth expression required")
 			if err != nil {
 				return err
 			}
@@ -2265,7 +2293,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--with-nth":
-			str, err := nextString(allArgs, &i, "nth expression required")
+			str, err := nextString("nth expression required")
 			if err != nil {
 				return err
 			}
@@ -2273,7 +2301,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "-s", "--sort":
-			if opts.Sort, err = optionalNumeric(allArgs, &i, 1); err != nil {
+			if opts.Sort, err = optionalNumeric(1); err != nil {
 				return err
 			}
 		case "+s", "--no-sort":
@@ -2287,7 +2315,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-tac":
 			opts.Tac = false
 		case "--tail":
-			if opts.Tail, err = nextInt(allArgs, &i, "number of items to keep required"); err != nil {
+			if opts.Tail, err = nextInt("number of items to keep required"); err != nil {
 				return err
 			}
 			if opts.Tail <= 0 {
@@ -2302,7 +2330,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "+i", "--no-ignore-case":
 			opts.Case = CaseRespect
 		case "-m", "--multi":
-			if opts.Multi, err = optionalNumeric(allArgs, &i, maxMulti); err != nil {
+			if opts.Multi, err = optionalNumeric(maxMulti); err != nil {
 				return err
 			}
 		case "+m", "--no-multi":
@@ -2326,7 +2354,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-bold":
 			opts.Bold = false
 		case "--layout":
-			str, err := nextString(allArgs, &i, "layout required (default / reverse / reverse-list)")
+			str, err := nextString("layout required (default / reverse / reverse-list)")
 			if err != nil {
 				return err
 			}
@@ -2350,7 +2378,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-wrap":
 			opts.Wrap = false
 		case "--wrap-sign":
-			str, err := nextString(allArgs, &i, "wrap sign required")
+			str, err := nextString("wrap sign required")
 			if err != nil {
 				return err
 			}
@@ -2368,11 +2396,11 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-hscroll":
 			opts.Hscroll = false
 		case "--hscroll-off":
-			if opts.HscrollOff, err = nextInt(allArgs, &i, "hscroll offset required"); err != nil {
+			if opts.HscrollOff, err = nextInt("hscroll offset required"); err != nil {
 				return err
 			}
 		case "--scroll-off":
-			if opts.ScrollOff, err = nextInt(allArgs, &i, "scroll offset required"); err != nil {
+			if opts.ScrollOff, err = nextInt("scroll offset required"); err != nil {
 				return err
 			}
 		case "--filepath-word":
@@ -2380,7 +2408,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-filepath-word":
 			opts.FileWord = false
 		case "--info":
-			str, err := nextString(allArgs, &i, "info style required")
+			str, err := nextString("info style required")
 			if err != nil {
 				return err
 			}
@@ -2388,7 +2416,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--info-command":
-			if opts.InfoCommand, err = nextString(allArgs, &i, "info command required"); err != nil {
+			if opts.InfoCommand, err = nextString("info command required"); err != nil {
 				return err
 			}
 		case "--no-info-command":
@@ -2401,7 +2429,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-inline-info":
 			opts.InfoStyle = infoDefault
 		case "--separator":
-			separator, err := nextString(allArgs, &i, "separator character required")
+			separator, err := nextString("separator character required")
 			if err != nil {
 				return err
 			}
@@ -2410,7 +2438,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			nosep := ""
 			opts.Separator = &nosep
 		case "--scrollbar":
-			given, bar := optionalNextString(allArgs, &i)
+			given, bar := optionalNextString()
 			if given {
 				opts.Scrollbar = &bar
 			} else {
@@ -2420,7 +2448,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			noBar := ""
 			opts.Scrollbar = &noBar
 		case "--jump-labels":
-			if opts.JumpLabels, err = nextString(allArgs, &i, "label characters required"); err != nil {
+			if opts.JumpLabels, err = nextString("label characters required"); err != nil {
 				return err
 			}
 			validateJumpLabels = true
@@ -2447,26 +2475,26 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-print-query":
 			opts.PrintQuery = false
 		case "--prompt":
-			opts.Prompt, err = nextString(allArgs, &i, "prompt string required")
+			opts.Prompt, err = nextString("prompt string required")
 			if err != nil {
 				return err
 			}
 		case "--pointer":
-			str, err := nextString(allArgs, &i, "pointer sign required")
+			str, err := nextString("pointer sign required")
 			if err != nil {
 				return err
 			}
 			str = firstLine(str)
 			opts.Pointer = &str
 		case "--marker":
-			str, err := nextString(allArgs, &i, "marker sign required")
+			str, err := nextString("marker sign required")
 			if err != nil {
 				return err
 			}
 			str = firstLine(str)
 			opts.Marker = &str
 		case "--marker-multi-line":
-			str, err := nextString(allArgs, &i, "marker sign for multi-line entries required")
+			str, err := nextString("marker sign for multi-line entries required")
 			if err != nil {
 				return err
 			}
@@ -2480,7 +2508,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-history":
 			opts.History = nil
 		case "--history":
-			str, err := nextString(allArgs, &i, "history file path required")
+			str, err := nextString("history file path required")
 			if err != nil {
 				return err
 			}
@@ -2488,7 +2516,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--history-size":
-			n, err := nextInt(allArgs, &i, "history max size required")
+			n, err := nextInt("history max size required")
 			if err != nil {
 				return err
 			}
@@ -2500,13 +2528,13 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-header-lines":
 			opts.HeaderLines = 0
 		case "--header":
-			str, err := nextString(allArgs, &i, "header string required")
+			str, err := nextString("header string required")
 			if err != nil {
 				return err
 			}
 			opts.Header = strLines(str)
 		case "--header-lines":
-			if opts.HeaderLines, err = nextInt(allArgs, &i, "number of header lines required"); err != nil {
+			if opts.HeaderLines, err = nextInt("number of header lines required"); err != nil {
 				return err
 			}
 		case "--header-first":
@@ -2514,26 +2542,26 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-header-first":
 			opts.HeaderFirst = false
 		case "--gap":
-			if opts.Gap, err = optionalNumeric(allArgs, &i, 1); err != nil {
+			if opts.Gap, err = optionalNumeric(1); err != nil {
 				return err
 			}
 		case "--no-gap":
 			opts.Gap = 0
 		case "--ellipsis":
-			str, err := nextString(allArgs, &i, "ellipsis string required")
+			str, err := nextString("ellipsis string required")
 			if err != nil {
 				return err
 			}
 			str = firstLine(str)
 			opts.Ellipsis = &str
 		case "--preview":
-			if opts.Preview.command, err = nextString(allArgs, &i, "preview command required"); err != nil {
+			if opts.Preview.command, err = nextString("preview command required"); err != nil {
 				return err
 			}
 		case "--no-preview":
 			opts.Preview.command = ""
 		case "--preview-window":
-			str, err := nextString(allArgs, &i, "preview window layout required: [up|down|left|right][,SIZE[%]][,border-STYLE][,wrap][,cycle][,hidden][,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES][,default]")
+			str, err := nextString("preview window layout required: [up|down|left|right][,SIZE[%]][,border-STYLE][,wrap][,cycle][,hidden][,+SCROLL[OFFSETS][/DENOM]][,~HEADER_LINES][,default]")
 			if err != nil {
 				return err
 			}
@@ -2543,12 +2571,12 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-preview-border":
 			opts.Preview.border = tui.BorderNone
 		case "--preview-border":
-			hasArg, arg := optionalNextString(allArgs, &i)
+			hasArg, arg := optionalNextString()
 			if opts.Preview.border, err = parseBorder(arg, !hasArg, true); err != nil {
 				return err
 			}
 		case "--height":
-			str, err := nextString(allArgs, &i, "height required: [~]HEIGHT[%]")
+			str, err := nextString("height required: [~]HEIGHT[%]")
 			if err != nil {
 				return err
 			}
@@ -2556,7 +2584,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--min-height":
-			if opts.MinHeight, err = nextInt(allArgs, &i, "height required: HEIGHT"); err != nil {
+			if opts.MinHeight, err = nextInt("height required: HEIGHT"); err != nil {
 				return err
 			}
 		case "--no-height":
@@ -2568,12 +2596,12 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-border":
 			opts.BorderShape = tui.BorderNone
 		case "--border":
-			hasArg, arg := optionalNextString(allArgs, &i)
+			hasArg, arg := optionalNextString()
 			if opts.BorderShape, err = parseBorder(arg, !hasArg, false); err != nil {
 				return err
 			}
 		case "--list-border":
-			hasArg, arg := optionalNextString(allArgs, &i)
+			hasArg, arg := optionalNextString()
 			if opts.ListBorderShape, err = parseBorder(arg, !hasArg, false); err != nil {
 				return err
 			}
@@ -2582,12 +2610,12 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-list-label":
 			opts.ListLabel.label = ""
 		case "--list-label":
-			opts.ListLabel.label, err = nextString(allArgs, &i, "label required")
+			opts.ListLabel.label, err = nextString("label required")
 			if err != nil {
 				return err
 			}
 		case "--list-label-pos":
-			pos, err := nextString(allArgs, &i, "label position required (positive or negative integer or 'center')")
+			pos, err := nextString("label position required (positive or negative integer or 'center')")
 			if err != nil {
 				return err
 			}
@@ -2597,18 +2625,18 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-header-border":
 			opts.HeaderBorderShape = tui.BorderNone
 		case "--header-border":
-			hasArg, arg := optionalNextString(allArgs, &i)
+			hasArg, arg := optionalNextString()
 			if opts.HeaderBorderShape, err = parseBorder(arg, !hasArg, false); err != nil {
 				return err
 			}
 		case "--no-header-label":
 			opts.HeaderLabel.label = ""
 		case "--header-label":
-			if opts.HeaderLabel.label, err = nextString(allArgs, &i, "header label required"); err != nil {
+			if opts.HeaderLabel.label, err = nextString("header label required"); err != nil {
 				return err
 			}
 		case "--header-label-pos":
-			pos, err := nextString(allArgs, &i, "header label position required (positive or negative integer or 'center')")
+			pos, err := nextString("header label position required (positive or negative integer or 'center')")
 			if err != nil {
 				return err
 			}
@@ -2618,18 +2646,18 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-input-border":
 			opts.InputBorderShape = tui.BorderNone
 		case "--input-border":
-			hasArg, arg := optionalNextString(allArgs, &i)
+			hasArg, arg := optionalNextString()
 			if opts.InputBorderShape, err = parseBorder(arg, !hasArg, false); err != nil {
 				return err
 			}
 		case "--no-input-label":
 			opts.InputLabel.label = ""
 		case "--input-label":
-			if opts.InputLabel.label, err = nextString(allArgs, &i, "input label required"); err != nil {
+			if opts.InputLabel.label, err = nextString("input label required"); err != nil {
 				return err
 			}
 		case "--input-label-pos":
-			pos, err := nextString(allArgs, &i, "input label position required (positive or negative integer or 'center')")
+			pos, err := nextString("input label position required (positive or negative integer or 'center')")
 			if err != nil {
 				return err
 			}
@@ -2639,12 +2667,12 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-border-label":
 			opts.BorderLabel.label = ""
 		case "--border-label":
-			opts.BorderLabel.label, err = nextString(allArgs, &i, "label required")
+			opts.BorderLabel.label, err = nextString("label required")
 			if err != nil {
 				return err
 			}
 		case "--border-label-pos":
-			pos, err := nextString(allArgs, &i, "label position required (positive or negative integer or 'center')")
+			pos, err := nextString("label position required (positive or negative integer or 'center')")
 			if err != nil {
 				return err
 			}
@@ -2654,11 +2682,11 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-preview-label":
 			opts.PreviewLabel.label = ""
 		case "--preview-label":
-			if opts.PreviewLabel.label, err = nextString(allArgs, &i, "preview label required"); err != nil {
+			if opts.PreviewLabel.label, err = nextString("preview label required"); err != nil {
 				return err
 			}
 		case "--preview-label-pos":
-			pos, err := nextString(allArgs, &i, "preview label position required (positive or negative integer or 'center')")
+			pos, err := nextString("preview label position required (positive or negative integer or 'center')")
 			if err != nil {
 				return err
 			}
@@ -2666,7 +2694,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--style":
-			preset, err := nextString(allArgs, &i, "preset name required: [default|minimal|full]")
+			preset, err := nextString("preset name required: [default|minimal|full]")
 			if err != nil {
 				return err
 			}
@@ -2682,7 +2710,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-ambidouble":
 			opts.Ambidouble = false
 		case "--margin":
-			str, err := nextString(allArgs, &i, "margin required (TRBL / TB,RL / T,RL,B / T,R,B,L)")
+			str, err := nextString("margin required (TRBL / TB,RL / T,RL,B / T,R,B,L)")
 			if err != nil {
 				return err
 			}
@@ -2690,7 +2718,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--padding":
-			str, err := nextString(allArgs, &i, "padding required (TRBL / TB,RL / T,RL,B / T,R,B,L)")
+			str, err := nextString("padding required (TRBL / TB,RL / T,RL,B / T,R,B,L)")
 			if err != nil {
 				return err
 			}
@@ -2698,15 +2726,15 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--tabstop":
-			if opts.Tabstop, err = nextInt(allArgs, &i, "tab stop required"); err != nil {
+			if opts.Tabstop, err = nextInt("tab stop required"); err != nil {
 				return err
 			}
 		case "--with-shell":
-			if opts.WithShell, err = nextString(allArgs, &i, "shell command and flags required"); err != nil {
+			if opts.WithShell, err = nextString("shell command and flags required"); err != nil {
 				return err
 			}
 		case "--listen", "--listen-unsafe":
-			given, str := optionalNextString(allArgs, &i)
+			given, str := optionalNextString()
 			addr := defaultListenAddr
 			if given {
 				var err error
@@ -2725,7 +2753,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 		case "--no-clear":
 			opts.ClearOnExit = false
 		case "--walker":
-			str, err := nextString(allArgs, &i, "walker options required [file][,dir][,follow][,hidden]")
+			str, err := nextString("walker options required [file][,dir][,follow][,hidden]")
 			if err != nil {
 				return err
 			}
@@ -2733,261 +2761,58 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 		case "--walker-root":
-			if opts.WalkerRoot, err = nextDirs(allArgs, &i); err != nil {
+			if opts.WalkerRoot, err = nextDirs(); err != nil {
 				return err
 			}
 		case "--walker-skip":
-			str, err := nextString(allArgs, &i, "directory names to ignore required")
+			str, err := nextString("directory names to ignore required")
 			if err != nil {
 				return err
 			}
 			opts.WalkerSkip = filterNonEmpty(strings.Split(str, ","))
 		case "--profile-cpu":
-			if opts.CPUProfile, err = nextString(allArgs, &i, "file path required: cpu"); err != nil {
+			if opts.CPUProfile, err = nextString("file path required: cpu"); err != nil {
 				return err
 			}
 		case "--profile-mem":
-			if opts.MEMProfile, err = nextString(allArgs, &i, "file path required: mem"); err != nil {
+			if opts.MEMProfile, err = nextString("file path required: mem"); err != nil {
 				return err
 			}
 		case "--profile-block":
-			if opts.BlockProfile, err = nextString(allArgs, &i, "file path required: block"); err != nil {
+			if opts.BlockProfile, err = nextString("file path required: block"); err != nil {
 				return err
 			}
 		case "--profile-mutex":
-			if opts.MutexProfile, err = nextString(allArgs, &i, "file path required: mutex"); err != nil {
+			if opts.MutexProfile, err = nextString("file path required: mutex"); err != nil {
 				return err
 			}
 		case "--":
 			// Ignored
 		default:
-			if match, value := optString(arg, "--algo="); match {
-				if opts.FuzzyAlgo, err = parseAlgo(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--tmux="); match {
-				if opts.Tmux, err = parseTmuxOptions(value, index); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--style="); match {
-				if err := applyPreset(opts, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--scheme="); match {
-				opts.Scheme = strings.ToLower(value)
-			} else if match, value := optString(arg, "-q", "--query="); match {
+			if match, value := optString(arg, "-q"); match {
 				opts.Query = value
-			} else if match, value := optString(arg, "-f", "--filter="); match {
+			} else if match, value := optString(arg, "-f"); match {
 				opts.Filter = &value
-			} else if match, value := optString(arg, "-d", "--delimiter="); match {
+			} else if match, value := optString(arg, "-d"); match {
 				opts.Delimiter = delimiterRegexp(value)
-			} else if match, value := optString(arg, "--border="); match {
-				if opts.BorderShape, err = parseBorder(value, false, false); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--preview-border="); match {
-				if opts.Preview.border, err = parseBorder(value, false, true); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--list-border="); match {
-				if opts.ListBorderShape, err = parseBorder(value, false, false); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--list-label="); match {
-				opts.ListLabel.label = value
-			} else if match, value := optString(arg, "--list-label-pos="); match {
-				if err := parseLabelPosition(&opts.ListLabel, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--input-border="); match {
-				if opts.InputBorderShape, err = parseBorder(value, false, false); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--input-label="); match {
-				opts.InputLabel.label = value
-			} else if match, value := optString(arg, "--input-label-pos="); match {
-				if err := parseLabelPosition(&opts.InputLabel, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--border-label="); match {
-				opts.BorderLabel.label = value
-			} else if match, value := optString(arg, "--border-label-pos="); match {
-				if err := parseLabelPosition(&opts.BorderLabel, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--preview-label="); match {
-				opts.PreviewLabel.label = value
-			} else if match, value := optString(arg, "--preview-label-pos="); match {
-				if err := parseLabelPosition(&opts.PreviewLabel, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--wrap-sign="); match {
-				opts.WrapSign = &value
-			} else if match, value := optString(arg, "--prompt="); match {
-				opts.Prompt = value
-			} else if match, value := optString(arg, "--pointer="); match {
-				str := firstLine(value)
-				opts.Pointer = &str
-			} else if match, value := optString(arg, "--marker="); match {
-				str := firstLine(value)
-				opts.Marker = &str
-			} else if match, value := optString(arg, "--marker-multi-line="); match {
-				if opts.MarkerMulti, err = parseMarkerMultiLine(firstLine(value)); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "-n", "--nth="); match {
+			} else if match, value := optString(arg, "-n"); match {
 				if opts.Nth, err = splitNth(value); err != nil {
 					return err
 				}
-			} else if match, value := optString(arg, "--with-nth="); match {
-				if opts.WithNth, err = splitNth(value); err != nil {
-					return err
-				}
-			} else if match, _ := optString(arg, "-s", "--sort="); match {
+			} else if match, _ := optString(arg, "-s"); match {
 				opts.Sort = 1 // Don't care
-			} else if match, value := optString(arg, "-m", "--multi="); match {
+			} else if match, value := optString(arg, "-m"); match {
 				if opts.Multi, err = atoi(value); err != nil {
 					return err
 				}
-			} else if match, value := optString(arg, "--height="); match {
-				if opts.Height, err = parseHeight(value, index); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--min-height="); match {
-				if opts.MinHeight, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--layout="); match {
-				if opts.Layout, err = parseLayout(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--info="); match {
-				if opts.InfoStyle, opts.InfoPrefix, err = parseInfoStyle(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--info-command="); match {
-				opts.InfoCommand = value
-			} else if match, value := optString(arg, "--separator="); match {
-				opts.Separator = &value
-			} else if match, value := optString(arg, "--scrollbar="); match {
-				opts.Scrollbar = &value
-			} else if match, value := optString(arg, "--toggle-sort="); match {
-				if err := parseToggleSort(opts.Keymap, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--expect="); match {
-				chords, err := parseKeyChords(value, "key names required")
-				if err != nil {
-					return err
-				}
-				for k, v := range chords {
-					opts.Expect[k] = v
-				}
-			} else if match, value := optString(arg, "--tiebreak="); match {
-				if opts.Criteria, err = parseTiebreak(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--color="); match {
-				if opts.Theme, err = parseTheme(opts.Theme, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--bind="); match {
-				if err := parseKeymap(opts.Keymap, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--history="); match {
-				if err := setHistory(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--history-size="); match {
-				n, err := atoi(value)
-				if err != nil {
-					return err
-				}
-				if err := setHistoryMax(n); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--header="); match {
-				opts.Header = strLines(value)
-			} else if match, value := optString(arg, "--header-lines="); match {
-				if opts.HeaderLines, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--gap="); match {
-				if opts.Gap, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--ellipsis="); match {
-				str := firstLine(value)
-				opts.Ellipsis = &str
-			} else if match, value := optString(arg, "--preview="); match {
-				opts.Preview.command = value
-			} else if match, value := optString(arg, "--preview-window="); match {
-				if err := parsePreviewWindow(&opts.Preview, value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--margin="); match {
-				if opts.Margin, err = parseMargin("margin", value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--padding="); match {
-				if opts.Padding, err = parseMargin("padding", value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--tabstop="); match {
-				if opts.Tabstop, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--with-shell="); match {
-				opts.WithShell = value
-			} else if match, value := optString(arg, "--listen="); match {
-				addr, err := parseListenAddress(value)
-				if err != nil {
-					return err
-				}
-				opts.ListenAddr = &addr
-				opts.Unsafe = false
-			} else if match, value := optString(arg, "--listen-unsafe="); match {
-				addr, err := parseListenAddress(value)
-				if err != nil {
-					return err
-				}
-				opts.ListenAddr = &addr
-				opts.Unsafe = true
-			} else if match, value := optString(arg, "--walker="); match {
-				if opts.WalkerOpts, err = parseWalkerOpts(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--walker-root="); match {
-				if !isDir(value) {
-					return errors.New("not a directory: " + value)
-				}
-				dirs, _ := nextDirs(allArgs, &i)
-				opts.WalkerRoot = append([]string{value}, dirs...)
-			} else if match, value := optString(arg, "--walker-skip="); match {
-				opts.WalkerSkip = filterNonEmpty(strings.Split(value, ","))
-			} else if match, value := optString(arg, "--hscroll-off="); match {
-				if opts.HscrollOff, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--scroll-off="); match {
-				if opts.ScrollOff, err = atoi(value); err != nil {
-					return err
-				}
-			} else if match, value := optString(arg, "--jump-labels="); match {
-				opts.JumpLabels = value
-				validateJumpLabels = true
-			} else if match, value := optString(arg, "--tail="); match {
-				if opts.Tail, err = atoi(value); err != nil {
-					return err
-				}
-				if opts.Tail <= 0 {
-					return errors.New("number of items to keep must be a positive integer")
-				}
 			} else {
 				return errors.New("unknown option: " + arg)
 			}
 		}
+
+		if val != nil {
+			return errors.New("unexpected value for " + arg + ": " + *val)
+		}
 	}
 	*index += len(allArgs)