Making more messes with parser config

argh/cmd/argh-example/main.go

@@ -15,7 +15,16 @@ func main() {
 
 	log.SetFlags(0)
 
-	pt, err := argh.ParseArgs(os.Args, nil)
+	pt, err := argh.ParseArgs(os.Args, argh.NewParserConfig(
+		&argh.CommandConfig{
+			NValue:     argh.OneOrMoreValue,
+			ValueNames: []string{"topping"},
+			Flags: &argh.Flags{
+				Automatic: true,
+			},
+		},
+		nil,
+	))
 	if err != nil {
 		log.Fatal(err)
 	}

argh/parser.go

@@ -11,7 +11,7 @@ type parser struct {
 
 	cfg *ParserConfig
 
-	errors ScannerErrorList
+	errors ParserErrorList
 
 	tok Token
 	lit string
@@ -36,8 +36,12 @@ func ParseArgs(args []string, pCfg *ParserConfig) (*ParseTree, error) {
 	return p.parseArgs()
 }
 
+func (p *parser) addError(msg string) {
+	p.errors.Add(Position{Column: int(p.pos)}, msg)
+}
+
 func (p *parser) init(r io.Reader, pCfg *ParserConfig) {
-	p.errors = ScannerErrorList{}
+	p.errors = ParserErrorList{}
 
 	if pCfg == nil {
 		pCfg = POSIXyParserConfig
@@ -103,7 +107,9 @@ func (p *parser) parseCommand(cCfg *CommandConfig) Node {
 		tracef("parseCommand(...) for=%d nodes=%+#v", i, nodes)
 		tracef("parseCommand(...) for=%d tok=%s lit=%q pos=%v", i, p.tok, p.lit, p.pos)
 
-		if subCfg, ok := cCfg.Commands[p.lit]; ok {
+		tracef("parseCommand(...) cCfg=%+#v", cCfg)
+
+		if subCfg, ok := cCfg.GetCommandConfig(p.lit); ok {
 			subCommand := p.lit
 
 			nodes = append(nodes, p.parseCommand(&subCfg))
@@ -156,7 +162,7 @@ func (p *parser) parseCommand(cCfg *CommandConfig) Node {
 		case ASSIGN:
 			tracef("parseCommand(...) error on bare %s", p.tok)
 
-			p.errors.Add(Position{Column: int(p.pos)}, "invalid bare assignment")
+			p.addError("invalid bare assignment")
 
 			break
 		default:
@@ -182,45 +188,49 @@ func (p *parser) parseIdent() Node {
 	return node
 }
 
-func (p *parser) parseFlag(flCfgMap map[string]FlagConfig) Node {
+func (p *parser) parseFlag(flags *Flags) Node {
 	switch p.tok {
 	case SHORT_FLAG:
-		tracef("parseFlag(...) parsing short flag with config=%+#v", flCfgMap)
-		return p.parseShortFlag(flCfgMap)
+		tracef("parseFlag(...) parsing short flag with config=%+#v", flags)
+		return p.parseShortFlag(flags)
 	case LONG_FLAG:
-		tracef("parseFlag(...) parsing long flag with config=%+#v", flCfgMap)
-		return p.parseLongFlag(flCfgMap)
+		tracef("parseFlag(...) parsing long flag with config=%+#v", flags)
+		return p.parseLongFlag(flags)
 	case COMPOUND_SHORT_FLAG:
-		tracef("parseFlag(...) parsing compound short flag with config=%+#v", flCfgMap)
-		return p.parseCompoundShortFlag(flCfgMap)
+		tracef("parseFlag(...) parsing compound short flag with config=%+#v", flags)
+		return p.parseCompoundShortFlag(flags)
 	}
 
 	panic(fmt.Sprintf("token %v cannot be parsed as flag", p.tok))
 }
 
-func (p *parser) parseShortFlag(flCfgMap map[string]FlagConfig) Node {
+func (p *parser) parseShortFlag(flags *Flags) Node {
 	node := &Flag{Name: string(p.lit[1])}
 
-	flCfg, ok := flCfgMap[node.Name]
+	flCfg, ok := flags.Get(node.Name)
 	if !ok {
+		p.addError(fmt.Sprintf("unknown flag %q", node.Name))
+
 		return node
 	}
 
 	return p.parseConfiguredFlag(node, flCfg)
 }
 
-func (p *parser) parseLongFlag(flCfgMap map[string]FlagConfig) Node {
+func (p *parser) parseLongFlag(flags *Flags) Node {
 	node := &Flag{Name: string(p.lit[2:])}
 
-	flCfg, ok := flCfgMap[node.Name]
+	flCfg, ok := flags.Get(node.Name)
 	if !ok {
+		p.addError(fmt.Sprintf("unknown flag %q", node.Name))
+
 		return node
 	}
 
 	return p.parseConfiguredFlag(node, flCfg)
 }
 
-func (p *parser) parseCompoundShortFlag(flCfgMap map[string]FlagConfig) Node {
+func (p *parser) parseCompoundShortFlag(flags *Flags) Node {
 	flagNodes := []Node{}
 
 	withoutFlagPrefix := p.lit[1:]
@@ -229,12 +239,16 @@ func (p *parser) parseCompoundShortFlag(flCfgMap map[string]FlagConfig) Node {
 		node := &Flag{Name: string(r)}
 
 		if i == len(withoutFlagPrefix)-1 {
-			flCfg, ok := flCfgMap[node.Name]
-			if ok {
-				flagNodes = append(flagNodes, p.parseConfiguredFlag(node, flCfg))
+			flCfg, ok := flags.Get(node.Name)
+			if !ok {
+				p.addError(fmt.Sprintf("unknown flag %q", node.Name))
 
 				continue
 			}
+
+			flagNodes = append(flagNodes, p.parseConfiguredFlag(node, flCfg))
+
+			continue
 		}
 
 		flagNodes = append(flagNodes, node)

argh/parser_config.go

@@ -7,15 +7,17 @@ const (
 )
 
 var (
-	POSIXyParserConfig = &ParserConfig{
-		Prog:          CommandConfig{},
-		ScannerConfig: POSIXyScannerConfig,
-	}
+	POSIXyParserConfig = NewParserConfig(
+		nil,
+		POSIXyScannerConfig,
+	)
 )
 
 type NValue int
 
 func (nv NValue) Contains(i int) bool {
+	tracef("NValue.Contains(%v)", i)
+
 	if i < int(ZeroValue) {
 		return false
 	}
@@ -33,14 +35,112 @@ type ParserConfig struct {
 	ScannerConfig *ScannerConfig
 }
 
+func NewParserConfig(prog *CommandConfig, sCfg *ScannerConfig) *ParserConfig {
+	if sCfg == nil {
+		sCfg = POSIXyScannerConfig
+	}
+
+	if prog == nil {
+		prog = &CommandConfig{}
+	}
+
+	prog.init()
+
+	pCfg := &ParserConfig{
+		Prog:          *prog,
+		ScannerConfig: sCfg,
+	}
+
+	return pCfg
+}
+
 type CommandConfig struct {
 	NValue     NValue
 	ValueNames []string
-	Flags      map[string]FlagConfig
-	Commands   map[string]CommandConfig
+	Flags      *Flags
+	Commands   *Commands
+}
+
+func (cCfg *CommandConfig) init() {
+	if cCfg.ValueNames == nil {
+		cCfg.ValueNames = []string{}
+	}
+
+	if cCfg.Flags == nil {
+		cCfg.Flags = &Flags{}
+	}
+
+	if cCfg.Commands == nil {
+		cCfg.Commands = &Commands{}
+	}
+}
+
+func (cCfg *CommandConfig) GetCommandConfig(name string) (CommandConfig, bool) {
+	tracef("CommandConfig.GetCommandConfig(%q)", name)
+
+	if cCfg.Commands == nil {
+		cCfg.Commands = &Commands{Map: map[string]CommandConfig{}}
+	}
+
+	return cCfg.Commands.Get(name)
+}
+
+func (cCfg *CommandConfig) GetFlagConfig(name string) (FlagConfig, bool) {
+	tracef("CommandConfig.GetFlagConfig(%q)", name)
+
+	if cCfg.Flags == nil {
+		cCfg.Flags = &Flags{Map: map[string]FlagConfig{}}
+	}
+
+	return cCfg.Flags.Get(name)
 }
 
 type FlagConfig struct {
 	NValue     NValue
+	Persist    bool
 	ValueNames []string
 }
+
+type Flags struct {
+	Parent *Flags
+	Map    map[string]FlagConfig
+
+	Automatic bool
+}
+
+func (fl *Flags) Get(name string) (FlagConfig, bool) {
+	tracef("Flags.Get(%q)", name)
+
+	if fl.Map == nil {
+		fl.Map = map[string]FlagConfig{}
+	}
+
+	flCfg, ok := fl.Map[name]
+	if !ok {
+		if fl.Automatic {
+			return FlagConfig{}, true
+		}
+
+		if fl.Parent != nil {
+			flCfg, ok = fl.Parent.Get(name)
+			return flCfg, ok && flCfg.Persist
+		}
+	}
+
+	return flCfg, ok
+}
+
+type Commands struct {
+	Map map[string]CommandConfig
+}
+
+func (cmd *Commands) Get(name string) (CommandConfig, bool) {
+	tracef("Commands.Get(%q)", name)
+
+	if cmd.Map == nil {
+		cmd.Map = map[string]CommandConfig{}
+	}
+
+	cmdCfg, ok := cmd.Map[name]
+	return cmdCfg, ok
+}

argh/parser_error.go

@@ -0,0 +1,88 @@
+package argh
+
+import (
+	"fmt"
+	"io"
+	"sort"
+)
+
+// ParserError is largely borrowed from go/scanner.Error
+type ParserError struct {
+	Pos Position
+	Msg string
+}
+
+func (e ParserError) Error() string {
+	if e.Pos.IsValid() {
+		return e.Pos.String() + ":" + e.Msg
+	}
+
+	return e.Msg
+}
+
+// ParserErrorList is largely borrowed from go/scanner.ErrorList
+type ParserErrorList []*ParserError
+
+func (el *ParserErrorList) Add(pos Position, msg string) {
+	*el = append(*el, &ParserError{Pos: pos, Msg: msg})
+}
+
+func (el *ParserErrorList) Reset() { *el = (*el)[0:0] }
+
+func (el ParserErrorList) Len() int { return len(el) }
+
+func (el ParserErrorList) Swap(i, j int) { el[i], el[j] = el[j], el[i] }
+
+func (el ParserErrorList) Less(i, j int) bool {
+	e := &el[i].Pos
+	f := &el[j].Pos
+
+	if e.Column != f.Column {
+		return e.Column < f.Column
+	}
+
+	return el[i].Msg < el[j].Msg
+}
+
+func (el ParserErrorList) Sort() {
+	sort.Sort(el)
+}
+
+func (el ParserErrorList) Error() string {
+	switch len(el) {
+	case 0:
+		return "no errors"
+	case 1:
+		return el[0].Error()
+	}
+	return fmt.Sprintf("%s (and %d more errors)", el[0], len(el)-1)
+}
+
+func (el ParserErrorList) Err() error {
+	if len(el) == 0 {
+		return nil
+	}
+	return el
+}
+
+func (el ParserErrorList) Is(other error) bool {
+	if _, ok := other.(ParserErrorList); ok {
+		return el.Error() == other.Error()
+	}
+
+	if v, ok := other.(*ParserErrorList); ok {
+		return el.Error() == (*v).Error()
+	}
+
+	return false
+}
+
+func PrintParserError(w io.Writer, err error) {
+	if list, ok := err.(ParserErrorList); ok {
+		for _, e := range list {
+			fmt.Fprintf(w, "%s\n", e)
+		}
+	} else if err != nil {
+		fmt.Fprintf(w, "%s\n", err)
+	}
+}

argh/parser_test.go

@@ -25,7 +25,16 @@ func TestParser(t *testing.T) {
 			},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"e":   {},
+							"a":   {},
+							"t":   {},
+							"wat": {},
+						},
+					},
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
 							"hello": argh.CommandConfig{
 								NValue:     1,
 								ValueNames: []string{"name"},
@@ -33,6 +42,7 @@ func TestParser(t *testing.T) {
 						},
 					},
 				},
+			},
 			expPT: []argh.Node{
 				&argh.Command{
 					Name: "pies",
@@ -82,6 +92,89 @@ func TestParser(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "persistent flags",
+			args: []string{
+				"pies", "--wat", "hello", "mario", "-eat",
+			},
+			cfg: &argh.ParserConfig{
+				Prog: func() argh.CommandConfig {
+					cmdCfg := argh.CommandConfig{
+						Flags: &argh.Flags{
+							Map: map[string]argh.FlagConfig{
+								"e":   {Persist: true},
+								"a":   {Persist: true},
+								"t":   {Persist: true},
+								"wat": {},
+							},
+						},
+					}
+
+					cmdCfg.Commands = &argh.Commands{
+						Map: map[string]argh.CommandConfig{
+							"hello": argh.CommandConfig{
+								NValue:     1,
+								ValueNames: []string{"name"},
+								Flags: &argh.Flags{
+									Parent: cmdCfg.Flags,
+									Map:    map[string]argh.FlagConfig{},
+								},
+							},
+						},
+					}
+
+					return cmdCfg
+				}(),
+			},
+			expPT: []argh.Node{
+				&argh.Command{
+					Name: "pies",
+					Nodes: []argh.Node{
+						&argh.ArgDelimiter{},
+						&argh.Flag{Name: "wat"},
+						&argh.ArgDelimiter{},
+						&argh.Command{
+							Name: "hello",
+							Values: map[string]string{
+								"name": "mario",
+							},
+							Nodes: []argh.Node{
+								&argh.ArgDelimiter{},
+								&argh.Ident{Literal: "mario"},
+								&argh.ArgDelimiter{},
+								&argh.CompoundShortFlag{
+									Nodes: []argh.Node{
+										&argh.Flag{Name: "e"},
+										&argh.Flag{Name: "a"},
+										&argh.Flag{Name: "t"},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			expAST: []argh.Node{
+				&argh.Command{
+					Name: "pies",
+					Nodes: []argh.Node{
+						&argh.Flag{Name: "wat"},
+						&argh.Command{
+							Name: "hello",
+							Values: map[string]string{
+								"name": "mario",
+							},
+							Nodes: []argh.Node{
+								&argh.Ident{Literal: "mario"},
+								&argh.Flag{Name: "e"},
+								&argh.Flag{Name: "a"},
+								&argh.Flag{Name: "t"},
+							},
+						},
+					},
+				},
+			},
+		},
 		{
 			name: "bare",
 			args: []string{"pizzas"},
@@ -173,6 +266,17 @@ func TestParser(t *testing.T) {
 		{
 			name: "long value-less flags",
 			args: []string{"pizzas", "--tasty", "--fresh", "--super-hot-right-now"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"tasty":               {},
+							"fresh":               {},
+							"super-hot-right-now": {},
+						},
+					},
+				},
+			},
 			expPT: []argh.Node{
 				&argh.Command{
 					Name: "pizzas",
@@ -209,10 +313,15 @@ func TestParser(t *testing.T) {
 			},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{},
-					Flags: map[string]argh.FlagConfig{
+					Commands: &argh.Commands{Map: map[string]argh.CommandConfig{}},
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"tasty":               {},
 							"fresh":               argh.FlagConfig{NValue: 1},
+							"super-hot-right-now": {},
 							"box":                 argh.FlagConfig{NValue: argh.OneOrMoreValue},
+							"please":              {},
+						},
 					},
 				},
 			},
@@ -281,6 +390,17 @@ func TestParser(t *testing.T) {
 		{
 			name: "short value-less flags",
 			args: []string{"pizzas", "-t", "-f", "-s"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"t": {},
+							"f": {},
+							"s": {},
+						},
+					},
+				},
+			},
 			expPT: []argh.Node{
 				&argh.Command{
 					Name: "pizzas",
@@ -308,6 +428,19 @@ func TestParser(t *testing.T) {
 		{
 			name: "compound short flags",
 			args: []string{"pizzas", "-aca", "-blol"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"a": {},
+							"b": {},
+							"c": {},
+							"l": {},
+							"o": {},
+						},
+					},
+				},
+			},
 			expPT: []argh.Node{
 				&argh.Command{
 					Name: "pizzas",
@@ -352,9 +485,15 @@ func TestParser(t *testing.T) {
 			args: []string{"pizzas", "-a", "--ca", "-b", "1312", "-lol"},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{},
-					Flags: map[string]argh.FlagConfig{
+					Commands: &argh.Commands{Map: map[string]argh.CommandConfig{}},
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"a":  {},
 							"b":  argh.FlagConfig{NValue: 1},
+							"ca": {},
+							"l":  {},
+							"o":  {},
+						},
 					},
 				},
 			},
@@ -411,14 +550,24 @@ func TestParser(t *testing.T) {
 			args: []string{"pizzas", "fly", "freely", "sometimes", "and", "other", "times", "fry", "deeply", "--forever"},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
 							"fly": argh.CommandConfig{
-							Commands: map[string]argh.CommandConfig{
-								"fry": argh.CommandConfig{},
+								Commands: &argh.Commands{
+									Map: map[string]argh.CommandConfig{
+										"fry": argh.CommandConfig{
+											Flags: &argh.Flags{
+												Map: map[string]argh.FlagConfig{
+													"forever": {},
 												},
 											},
 										},
-					Flags: map[string]argh.FlagConfig{},
+									},
+								},
+							},
+						},
+					},
+					Flags: &argh.Flags{Map: map[string]argh.FlagConfig{}},
 				},
 			},
 			expPT: []argh.Node{
@@ -484,7 +633,8 @@ func TestParser(t *testing.T) {
 			args: []string{"pizzas", "-need", "sauce", "heat", "love", "-also", "over9000"},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Flags: map[string]argh.FlagConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
 							"a": {NValue: argh.ZeroOrMoreValue},
 							"d": {NValue: argh.OneOrMoreValue},
 							"e": {},
@@ -495,6 +645,7 @@ func TestParser(t *testing.T) {
 						},
 					},
 				},
+			},
 			expPT: []argh.Node{
 				&argh.Command{
 					Name: "pizzas",
@@ -585,14 +736,19 @@ func TestParser(t *testing.T) {
 			args: []string{"pizzas", "fly", "--freely", "fry", "--deeply", "-wAt", "hugs"},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
 							"fly": argh.CommandConfig{
-							Flags: map[string]argh.FlagConfig{
+								Flags: &argh.Flags{
+									Map: map[string]argh.FlagConfig{
 										"freely": {},
 									},
-							Commands: map[string]argh.CommandConfig{
+								},
+								Commands: &argh.Commands{
+									Map: map[string]argh.CommandConfig{
 										"fry": argh.CommandConfig{
-									Flags: map[string]argh.FlagConfig{
+											Flags: &argh.Flags{
+												Map: map[string]argh.FlagConfig{
 													"deeply": {},
 													"w":      {},
 													"A":      {},
@@ -602,7 +758,10 @@ func TestParser(t *testing.T) {
 										},
 									},
 								},
-					Flags: map[string]argh.FlagConfig{},
+							},
+						},
+					},
+					Flags: &argh.Flags{Map: map[string]argh.FlagConfig{}},
 				},
 			},
 			expPT: []argh.Node{
@@ -677,19 +836,25 @@ func TestParser(t *testing.T) {
 			args: []string{"PIZZAs", "^wAT@golf", "^^hecKing", "goose", "bonk", "^^FIERCENESS@-2"},
 			cfg: &argh.ParserConfig{
 				Prog: argh.CommandConfig{
-					Commands: map[string]argh.CommandConfig{
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
 							"goose": argh.CommandConfig{
 								NValue: 1,
-							Flags: map[string]argh.FlagConfig{
+								Flags: &argh.Flags{
+									Map: map[string]argh.FlagConfig{
 										"FIERCENESS": argh.FlagConfig{NValue: 1},
 									},
 								},
 							},
-					Flags: map[string]argh.FlagConfig{
+						},
+					},
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
 							"w":       argh.FlagConfig{},
 							"A":       argh.FlagConfig{},
 							"T":       argh.FlagConfig{NValue: 1},
-						"hecking": argh.FlagConfig{},
+							"hecKing": argh.FlagConfig{},
+						},
 					},
 				},
 				ScannerConfig: &argh.ScannerConfig{
@@ -741,11 +906,67 @@ func TestParser(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "windows like",
+			args: []string{"hotdog", "/f", "/L", "/o:ppy", "hats"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"f": {},
+							"L": {},
+							"o": argh.FlagConfig{NValue: 1},
+						},
+					},
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
+							"hats": {},
+						},
+					},
+				},
+				ScannerConfig: &argh.ScannerConfig{
+					AssignmentOperator: ':',
+					FlagPrefix:         '/',
+					MultiValueDelim:    ',',
+				},
+			},
+			expPT: []argh.Node{
+				&argh.Command{
+					Name: "hotdog",
+					Nodes: []argh.Node{
+						&argh.ArgDelimiter{},
+						&argh.Flag{Name: "f"},
+						&argh.ArgDelimiter{},
+						&argh.Flag{Name: "L"},
+						&argh.ArgDelimiter{},
+						&argh.Flag{
+							Name:   "o",
+							Values: map[string]string{"0": "ppy"},
+							Nodes: []argh.Node{
+								&argh.Assign{},
+								&argh.Ident{Literal: "ppy"},
+							},
+						},
+						&argh.ArgDelimiter{},
+						&argh.Command{Name: "hats"},
+					},
+				},
+			},
+		},
 		{
 			name: "invalid bare assignment",
 			args: []string{"pizzas", "=", "--wat"},
-			expErr: argh.ScannerErrorList{
-				&argh.ScannerError{Pos: argh.Position{Column: 8}, Msg: "invalid bare assignment"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Flags: &argh.Flags{
+						Map: map[string]argh.FlagConfig{
+							"wat": {},
+						},
+					},
+				},
+			},
+			expErr: argh.ParserErrorList{
+				&argh.ParserError{Pos: argh.Position{Column: 8}, Msg: "invalid bare assignment"},
 			},
 			expPT: []argh.Node{
 				&argh.Command{

argh/querier_test.go

@@ -18,6 +18,21 @@ func TestQuerier_Program(t *testing.T) {
 		{
 			name: "typical",
 			args: []string{"pizzas", "ahoy", "--treatsa", "fun"},
+			cfg: &argh.ParserConfig{
+				Prog: argh.CommandConfig{
+					Commands: &argh.Commands{
+						Map: map[string]argh.CommandConfig{
+							"ahoy": argh.CommandConfig{
+								Flags: &argh.Flags{
+									Map: map[string]argh.FlagConfig{
+										"treatsa": argh.FlagConfig{NValue: 1},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
 			exp:   "pizzas",
 			expOK: true,
 		},

argh/scanner_error.go

@@ -1,88 +0,0 @@
-package argh
-
-import (
-	"fmt"
-	"io"
-	"sort"
-)
-
-// ScannerError is largely borrowed from go/scanner.Error
-type ScannerError struct {
-	Pos Position
-	Msg string
-}
-
-func (e ScannerError) Error() string {
-	if e.Pos.IsValid() {
-		return e.Pos.String() + ":" + e.Msg
-	}
-
-	return e.Msg
-}
-
-// ScannerErrorList is largely borrowed from go/scanner.ErrorList
-type ScannerErrorList []*ScannerError
-
-func (el *ScannerErrorList) Add(pos Position, msg string) {
-	*el = append(*el, &ScannerError{Pos: pos, Msg: msg})
-}
-
-func (el *ScannerErrorList) Reset() { *el = (*el)[0:0] }
-
-func (el ScannerErrorList) Len() int { return len(el) }
-
-func (el ScannerErrorList) Swap(i, j int) { el[i], el[j] = el[j], el[i] }
-
-func (el ScannerErrorList) Less(i, j int) bool {
-	e := &el[i].Pos
-	f := &el[j].Pos
-
-	if e.Column != f.Column {
-		return e.Column < f.Column
-	}
-
-	return el[i].Msg < el[j].Msg
-}
-
-func (el ScannerErrorList) Sort() {
-	sort.Sort(el)
-}
-
-func (el ScannerErrorList) Error() string {
-	switch len(el) {
-	case 0:
-		return "no errors"
-	case 1:
-		return el[0].Error()
-	}
-	return fmt.Sprintf("%s (and %d more errors)", el[0], len(el)-1)
-}
-
-func (el ScannerErrorList) Err() error {
-	if len(el) == 0 {
-		return nil
-	}
-	return el
-}
-
-func (el ScannerErrorList) Is(other error) bool {
-	if _, ok := other.(ScannerErrorList); ok {
-		return el.Error() == other.Error()
-	}
-
-	if v, ok := other.(*ScannerErrorList); ok {
-		return el.Error() == (*v).Error()
-	}
-
-	return false
-}
-
-func PrintScannerError(w io.Writer, err error) {
-	if list, ok := err.(ScannerErrorList); ok {
-		for _, e := range list {
-			fmt.Fprintf(w, "%s\n", e)
-		}
-	} else if err != nil {
-		fmt.Fprintf(w, "%s\n", err)
-	}
-}