cli: simplify option model per pike review

- appendList: one home for the List newline-join rule (was duplicated
  across accumulate and set)
- fold the redundant Int64 getter into Int; drop the truthy helper for
  the shared boolWord vocabulary
- add Opt.Metavar so help derives the value placeholder from data
  instead of branching on the option name (seed-time)

No behavior change; --help output is byte-identical.

cli/help.go

@@ -89,24 +89,31 @@ func flagLabel(o *Opt) string {
 		b.WriteString("    ")
 	}
 	b.WriteString("--" + o.Long)
-	switch o.Kind {
+	if m := metavar(o); m != "" {
-	case Bool:
+		b.WriteString("=" + m)
-		// no argument shown
-	case Size:
-		b.WriteString("=SIZE")
-	case Int:
-		b.WriteString("=N")
-	case Float:
-		// seed-time is a count of minutes; only seed-ratio is an actual ratio.
-		if o.Long == "seed-time" {
-			b.WriteString("=MIN")
-		} else {
-			b.WriteString("=RATIO")
-		}
-	case Enum:
-		b.WriteString("=" + strings.Join(o.Enum, "|"))
-	default:
-		b.WriteString("=VAL")
 	}
 	return b.String()
 }
+
+// metavar is the placeholder shown after a value-taking flag, e.g. the "N" in
+// "--split=N". An explicit Opt.Metavar wins; otherwise it derives from the Kind.
+// Bool takes no value, so its metavar is empty and no "=ARG" is printed.
+func metavar(o *Opt) string {
+	if o.Metavar != "" {
+		return o.Metavar
+	}
+	switch o.Kind {
+	case Bool:
+		return ""
+	case Size:
+		return "SIZE"
+	case Int:
+		return "N"
+	case Float:
+		return "RATIO"
+	case Enum:
+		return strings.Join(o.Enum, "|")
+	default:
+		return "VAL"
+	}
+}

cli/option.go

@@ -50,6 +50,10 @@ type Opt struct {
 	Kind    Kind
 	Default string
 	Help    string
+	// Metavar overrides the "=PLACEHOLDER" shown after the flag in --help. Empty
+	// means derive it from Kind (N, SIZE, RATIO, ...). Set it only when the
+	// Kind-derived default would mislead, e.g. seed-time is minutes, not a ratio.
+	Metavar string
 	Tag     Tag
 	Enum    []string // valid values when Kind == Enum
 	// Min is the inclusive lower Int/Size bound. The zero value enforces a
@@ -103,7 +107,7 @@ var options = []Opt{
 
 	// --- bittorrent ---
 	{Long: "torrent-file", Short: 'T', Kind: Str, Help: "path to a .torrent file", Tag: BitTorrent},
-	{Long: "seed-time", Kind: Float, Help: "minutes to seed after completion (0 = no seeding)", Tag: BitTorrent},
+	{Long: "seed-time", Kind: Float, Metavar: "MIN", Help: "minutes to seed after completion (0 = no seeding)", Tag: BitTorrent},
 	{Long: "seed-ratio", Kind: Float, Default: "1.0", Help: "stop seeding at this share ratio (0 = unlimited)", Tag: BitTorrent},
 	{Long: "bt-stop-timeout", Kind: Int, Default: "0", Min: 0, Help: "stop a torrent with no download progress for N seconds (0 = off)", Tag: BitTorrent},
 	{Long: "bt-metadata-timeout", Kind: Int, Default: "60", Min: 0, Help: "stop a magnet that can't fetch metadata in N seconds (0 = off)", Tag: BitTorrent},

cli/options.go

@@ -48,13 +48,11 @@ func (o *Options) Bool(name string) bool {
 	return val
 }
 
-// Int returns the value as an int, or 0 if empty/invalid.
+// Int returns the value as an int, or 0 if empty/invalid. The value has already
-func (o *Options) Int(name string) int { return int(o.Int64(name)) }
+// passed validate(), so a parse failure here is unreachable in normal flow.
-
+func (o *Options) Int(name string) int {
-// Int64 returns the value as an int64, or 0 if empty/invalid.
-func (o *Options) Int64(name string) int64 {
 	n, _ := strconv.ParseInt(strings.TrimSpace(o.vals[name]), 10, 64)
-	return n
+	return int(n)
 }
 
 // Float returns the value as a float64, or 0 if empty/invalid.

cli/parse.go

@@ -41,7 +41,7 @@ func Parse(args []string) (*Result, error) {
 	opts := newOptions()
 	applyDefaults(opts)
 
-	if !truthy(cmdVals["no-conf"]) {
+	if noConf, _ := boolWord(cmdVals["no-conf"]); !noConf {
 		explicit := cmdVals["conf-path"]
 		path, fromUser := confPath(explicit)
 		if err := applyConfig(opts, path, fromUser); err != nil {
@@ -138,14 +138,23 @@ func parseArgs(args []string) (vals map[string]string, uris []string, action Act
 // accumulate stores a value, joining repeatable List options with newlines.
 func accumulate(vals map[string]string, o *Opt, val string) {
 	if o.Kind == List {
-		if prev, ok := vals[o.Long]; ok {
+		vals[o.Long] = appendList(vals[o.Long], val)
-			vals[o.Long] = prev + "\n" + val
 		return
 	}
-	}
 	vals[o.Long] = val
 }
 
+// appendList is the single home of the List newline-join rule, shared by the
+// raw-parse layer (accumulate) and the resolved layer (set). An empty prev (the
+// option not yet seen) yields val unchanged, so the first value carries no
+// leading newline.
+func appendList(prev, val string) string {
+	if prev == "" {
+		return val
+	}
+	return prev + "\n" + val
+}
+
 func applyDefaults(o *Options) {
 	for i := range options {
 		opt := &options[i]
@@ -215,10 +224,8 @@ func set(o *Options, name, val string) error {
 	if err := validate(opt, val); err != nil {
 		return err
 	}
-	if opt.Kind == List {
+	if opt.Kind == List && o.set[name] {
-		if prev, ok := o.vals[name]; ok && o.set[name] {
+		val = appendList(o.vals[name], val)
-			val = prev + "\n" + val
-		}
 	}
 	o.vals[name] = val
 	o.set[name] = true
@@ -304,8 +311,3 @@ func confPath(explicit string) (path string, fromUser bool) {
 	}
 	return filepath.Join(home, ".config", "got", "got.conf"), false
 }
-
-func truthy(s string) bool {
-	val, _ := boolWord(s)
-	return val
-}