Declare correct module name

.gitignore

@@ -0,0 +1,5 @@
+*.a
+*.exe
+*.o
+*.out
+*.so

README.md

@@ -1,4 +1,26 @@
 # argh command line parser
 
-> NOTE: much of this is lifted from
-> https://blog.gopheracademy.com/advent-2014/parsers-lexers/
+## background
+
+The Go standard library [flag](https://pkg.go.dev/flag) way of doing things has long been
+a source of frustration while implementing and maintaining the
+[urfave/cli](https://github.com/urfave/cli) library. [Many alternate parsers
+exist](https://github.com/avelino/awesome-go#standard-cli), including:
+
+- [pflag](https://github.com/spf13/pflag)
+- [argparse](https://github.com/akamensky/argparse)
+
+In addition to these other implementations, I also got some help via [this
+oldie](https://blog.gopheracademy.com/advent-2014/parsers-lexers/) and the Go standard
+library [parser](https://pkg.go.dev/go/parser).
+
+## goals
+
+- get a better understanding of the whole problem space
+- support both POSIX-y and Windows-y styles
+- build a printable/JSON-able parse tree
+- support rich error reporting
+
+<!--
+vim:tw=90
+-->

cmd/argh-example/main.go

@@ -6,7 +6,7 @@ import (
 	"log"
 	"os"
 
-	"git.meatballhat.com/x/box-o-sand/argh"
+	"git.meatballhat.com/x/argh"
 	"github.com/davecgh/go-spew/spew"
 )
 
@@ -15,16 +15,16 @@ func main() {
 
 	log.SetFlags(0)
 
-	pt, err := argh.ParseArgs(os.Args, argh.NewParserConfig(
-		&argh.CommandConfig{
-			NValue:     argh.OneOrMoreValue,
-			ValueNames: []string{"topping"},
-			Flags: &argh.Flags{
-				Automatic: true,
-			},
+	pCfg := argh.NewParserConfig()
+	pCfg.Prog = &argh.CommandConfig{
+		NValue:     argh.OneOrMoreValue,
+		ValueNames: []string{"val"},
+		Flags: &argh.Flags{
+			Automatic: true,
 		},
-		nil,
-	))
+	}
+
+	pt, err := argh.ParseArgs(os.Args, pCfg)
 	if err != nil {
 		log.Fatal(err)
 	}

go.mod

@@ -1,4 +1,4 @@
-module git.meatballhat.com/x/box-o-sand/argh
+module git.meatballhat.com/x/argh
 
 go 1.18
 

parser.go

@@ -61,7 +61,7 @@ func (p *parser) parseArgs() (*ParseTree, error) {
 	}
 
 	tracef("parseArgs() parsing %q as program command; cfg=%+#v", p.lit, p.cfg.Prog)
-	prog := p.parseCommand(&p.cfg.Prog)
+	prog := p.parseCommand(p.cfg.Prog)
 
 	tracef("parseArgs() top level node is %T", prog)
 

parser_config.go

@@ -7,10 +7,7 @@ const (
 )
 
 var (
-	POSIXyParserConfig = NewParserConfig(
-		nil,
-		POSIXyScannerConfig,
-	)
+	POSIXyParserConfig = NewParserConfig()
 )
 
 type NValue int
@@ -30,25 +27,29 @@ func (nv NValue) Contains(i int) bool {
 }
 
 type ParserConfig struct {
-	Prog CommandConfig
+	Prog *CommandConfig
 
 	ScannerConfig *ScannerConfig
 }
 
-func NewParserConfig(prog *CommandConfig, sCfg *ScannerConfig) *ParserConfig {
-	if sCfg == nil {
-		sCfg = POSIXyScannerConfig
+type ParserOption func(*ParserConfig)
+
+func NewParserConfig(opts ...ParserOption) *ParserConfig {
+	pCfg := &ParserConfig{}
+
+	for _, opt := range opts {
+		if opt != nil {
+			opt(pCfg)
+		}
 	}
 
-	if prog == nil {
-		prog = &CommandConfig{}
+	if pCfg.Prog == nil {
+		pCfg.Prog = &CommandConfig{}
+		pCfg.Prog.init()
 	}
 
-	prog.init()
-
-	pCfg := &ParserConfig{
-		Prog:          *prog,
-		ScannerConfig: sCfg,
+	if pCfg.ScannerConfig == nil {
+		pCfg.ScannerConfig = POSIXyScannerConfig
 	}
 
 	return pCfg

parser_test.go

@@ -3,7 +3,7 @@ package argh_test
 import (
 	"testing"
 
-	"git.meatballhat.com/x/box-o-sand/argh"
+	"git.meatballhat.com/x/argh"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/stretchr/testify/assert"
 )
@@ -24,7 +24,7 @@ func TestParser(t *testing.T) {
 				"pies", "-eat", "--wat", "hello", "mario",
 			},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"e":   {},
@@ -98,8 +98,8 @@ func TestParser(t *testing.T) {
 				"pies", "--wat", "hello", "mario", "-eat",
 			},
 			cfg: &argh.ParserConfig{
-				Prog: func() argh.CommandConfig {
-					cmdCfg := argh.CommandConfig{
+				Prog: func() *argh.CommandConfig {
+					cmdCfg := &argh.CommandConfig{
 						Flags: &argh.Flags{
 							Map: map[string]argh.FlagConfig{
 								"e":   {Persist: true},
@@ -193,7 +193,7 @@ func TestParser(t *testing.T) {
 			name: "one positional arg",
 			args: []string{"pizzas", "excel"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{NValue: 1},
+				Prog: &argh.CommandConfig{NValue: 1},
 			},
 			expPT: []argh.Node{
 				&argh.Command{
@@ -219,7 +219,7 @@ func TestParser(t *testing.T) {
 			name: "many positional args",
 			args: []string{"pizzas", "excel", "wildly", "when", "feral"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					NValue:     argh.OneOrMoreValue,
 					ValueNames: []string{"word"},
 				},
@@ -267,7 +267,7 @@ 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{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"tasty":               {},
@@ -312,7 +312,7 @@ func TestParser(t *testing.T) {
 				"--please",
 			},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{Map: map[string]argh.CommandConfig{}},
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
@@ -391,7 +391,7 @@ func TestParser(t *testing.T) {
 			name: "short value-less flags",
 			args: []string{"pizzas", "-t", "-f", "-s"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"t": {},
@@ -429,7 +429,7 @@ func TestParser(t *testing.T) {
 			name: "compound short flags",
 			args: []string{"pizzas", "-aca", "-blol"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"a": {},
@@ -484,7 +484,7 @@ func TestParser(t *testing.T) {
 			name: "mixed long short value flags",
 			args: []string{"pizzas", "-a", "--ca", "-b", "1312", "-lol"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{Map: map[string]argh.CommandConfig{}},
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
@@ -549,7 +549,7 @@ func TestParser(t *testing.T) {
 			name: "nested commands with positional args",
 			args: []string{"pizzas", "fly", "freely", "sometimes", "and", "other", "times", "fry", "deeply", "--forever"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{
 						Map: map[string]argh.CommandConfig{
 							"fly": argh.CommandConfig{
@@ -632,7 +632,7 @@ func TestParser(t *testing.T) {
 			name: "compound flags with values",
 			args: []string{"pizzas", "-need", "sauce", "heat", "love", "-also", "over9000"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"a": {NValue: argh.ZeroOrMoreValue},
@@ -735,7 +735,7 @@ func TestParser(t *testing.T) {
 			name: "command specific flags",
 			args: []string{"pizzas", "fly", "--freely", "fry", "--deeply", "-wAt", "hugs"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{
 						Map: map[string]argh.CommandConfig{
 							"fly": argh.CommandConfig{
@@ -835,7 +835,7 @@ func TestParser(t *testing.T) {
 			name: "total weirdo",
 			args: []string{"PIZZAs", "^wAT@golf", "^^hecKing", "goose", "bonk", "^^FIERCENESS@-2"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{
 						Map: map[string]argh.CommandConfig{
 							"goose": argh.CommandConfig{
@@ -910,7 +910,7 @@ func TestParser(t *testing.T) {
 			name: "windows like",
 			args: []string{"hotdog", "/f", "/L", "/o:ppy", "hats"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"f": {},
@@ -957,7 +957,7 @@ func TestParser(t *testing.T) {
 			name: "invalid bare assignment",
 			args: []string{"pizzas", "=", "--wat"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Flags: &argh.Flags{
 						Map: map[string]argh.FlagConfig{
 							"wat": {},

querier_test.go

@@ -3,7 +3,7 @@ package argh_test
 import (
 	"testing"
 
-	"git.meatballhat.com/x/box-o-sand/argh"
+	"git.meatballhat.com/x/argh"
 	"github.com/stretchr/testify/require"
 )
 
@@ -19,7 +19,7 @@ func TestQuerier_Program(t *testing.T) {
 			name: "typical",
 			args: []string{"pizzas", "ahoy", "--treatsa", "fun"},
 			cfg: &argh.ParserConfig{
-				Prog: argh.CommandConfig{
+				Prog: &argh.CommandConfig{
 					Commands: &argh.Commands{
 						Map: map[string]argh.CommandConfig{
 							"ahoy": argh.CommandConfig{

scanner_test.go

@@ -0,0 +1,83 @@
+package argh
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func BenchmarkScannerPOSIXyScannerScan(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		scanner := NewScanner(strings.NewReader(strings.Join([]string{
+			"walrus",
+			"-what",
+			"--ball=awesome",
+			"--elapsed",
+			"carrot cake",
+		}, string(nul))), nil)
+		for {
+			tok, _, _ := scanner.Scan()
+			if tok == EOL {
+				break
+			}
+		}
+	}
+}
+
+func TestScannerPOSIXyScanner(t *testing.T) {
+	for _, tc := range []struct {
+		name              string
+		argv              []string
+		expectedTokens    []Token
+		expectedLiterals  []string
+		expectedPositions []Pos
+	}{
+		{
+			name: "simple",
+			argv: []string{"walrus", "-cake", "--corn-dog", "awkward"},
+			expectedTokens: []Token{
+				IDENT,
+				ARG_DELIMITER,
+				COMPOUND_SHORT_FLAG,
+				ARG_DELIMITER,
+				LONG_FLAG,
+				ARG_DELIMITER,
+				IDENT,
+				EOL,
+			},
+			expectedLiterals: []string{
+				"walrus", string(nul), "-cake", string(nul), "--corn-dog", string(nul), "awkward", "",
+			},
+			expectedPositions: []Pos{
+				6, 7, 12, 13, 23, 24, 31, 32,
+			},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			r := require.New(t)
+
+			scanner := NewScanner(strings.NewReader(strings.Join(tc.argv, string(nul))), nil)
+
+			actualTokens := []Token{}
+			actualLiterals := []string{}
+			actualPositions := []Pos{}
+
+			for {
+				tok, lit, pos := scanner.Scan()
+
+				actualTokens = append(actualTokens, tok)
+				actualLiterals = append(actualLiterals, lit)
+				actualPositions = append(actualPositions, pos)
+
+				if tok == EOL {
+					break
+				}
+			}
+
+			r.Equal(tc.expectedTokens, actualTokens)
+			r.Equal(tc.expectedLiterals, actualLiterals)
+			r.Equal(tc.expectedPositions, actualPositions)
+		})
+	}
+}