cmd/gotext/main.go - text - Git at Google

 // Copyright 2016 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 //go:generate go build -o gotext.latest
 //go:generate ./gotext.latest help gendocumentation
 //go:generate rm gotext.latest

 package main

 import (
 	"bufio"
 	"bytes"
 	"flag"
 	"fmt"
 	"go/build"
 	"go/format"
 	"io"
 	"log"
 	"os"
 	"strings"
 	"sync"
 	"text/template"
 	"unicode"
 	"unicode/utf8"

 	"golang.org/x/text/message/pipeline"

 	"golang.org/x/text/language"
 	"golang.org/x/tools/go/buildutil"
 )

 func init() {
 	flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
 }

 var (
 	srcLang = flag.String("srclang", "en-US", "the source-code language")
 	dir     = flag.String("dir", "locales", "default subdirectory to store translation files")
 )

 func config() (*pipeline.Config, error) {
 	tag, err := language.Parse(*srcLang)
 	if err != nil {
 		return nil, wrap(err, "invalid srclang")
 	}
 	return &pipeline.Config{
 		SourceLanguage:      tag,
 		Supported:           getLangs(),
 		TranslationsPattern: `messages\.(.*)\.json$`,
 		GenFile:             *out,
 	}, nil
 }

 // NOTE: the Command struct is copied from the go tool in core.

 // A Command is an implementation of a go command
 // like go build or go fix.
 type Command struct {
 	// Run runs the command.
 	// The args are the arguments after the command name.
 	Run func(cmd *Command, c *pipeline.Config, args []string) error

 	// UsageLine is the one-line usage message.
 	// The first word in the line is taken to be the command name.
 	UsageLine string

 	// Short is the short description shown in the 'go help' output.
 	Short string

 	// Long is the long message shown in the 'go help <this-command>' output.
 	Long string

 	// Flag is a set of flags specific to this command.
 	Flag flag.FlagSet
 }

 // Name returns the command's name: the first word in the usage line.
 func (c *Command) Name() string {
 	name := c.UsageLine
 	i := strings.Index(name, " ")
 	if i >= 0 {
 		name = name[:i]
 	}
 	return name
 }

 func (c *Command) Usage() {
 	fmt.Fprintf(os.Stderr, "usage: %s\n\n", c.UsageLine)
 	fmt.Fprintf(os.Stderr, "%s\n", strings.TrimSpace(c.Long))
 	os.Exit(2)
 }

 // Runnable reports whether the command can be run; otherwise
 // it is a documentation pseudo-command such as importpath.
 func (c *Command) Runnable() bool {
 	return c.Run != nil
 }

 // Commands lists the available commands and help topics.
 // The order here is the order in which they are printed by 'go help'.
 var commands = []*Command{
 	cmdUpdate,
 	cmdExtract,
 	cmdRewrite,
 	cmdGenerate,
 	// TODO:
 	// - update: full-cycle update of extraction, sending, and integration
 	// - report: report of freshness of translations
 }

 var exitStatus = 0
 var exitMu sync.Mutex

 func setExitStatus(n int) {
 	exitMu.Lock()
 	if exitStatus < n {
 		exitStatus = n
 	}
 	exitMu.Unlock()
 }

 var origEnv []string

 func main() {
 	flag.Usage = usage
 	flag.Parse()
 	log.SetFlags(0)

 	args := flag.Args()
 	if len(args) < 1 {
 		usage()
 	}

 	if args[0] == "help" {
 		help(args[1:])
 		return
 	}

 	for _, cmd := range commands {
 		if cmd.Name() == args[0] && cmd.Runnable() {
 			cmd.Flag.Usage = func() { cmd.Usage() }
 			cmd.Flag.Parse(args[1:])
 			args = cmd.Flag.Args()
 			config, err := config()
 			if err != nil {
 				fatalf("gotext: %+v", err)
 			}
 			if err := cmd.Run(cmd, config, args); err != nil {
 				fatalf("gotext: %+v", err)
 			}
 			exit()
 			return
 		}
 	}

 	fmt.Fprintf(os.Stderr, "gotext: unknown subcommand %q\nRun 'go help' for usage.\n", args[0])
 	setExitStatus(2)
 	exit()
 }

 var usageTemplate = `gotext is a tool for managing text in Go source code.

 Usage:

 	gotext command [arguments]

 The commands are:
 {{range .}}{{if .Runnable}}
 	{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}

 Use "gotext help [command]" for more information about a command.

 Additional help topics:
 {{range .}}{{if not .Runnable}}
 	{{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}

 Use "gotext help [topic]" for more information about that topic.

 `

 var helpTemplate = `{{if .Runnable}}usage: gotext {{.UsageLine}}

 {{end}}{{.Long | trim}}
 `

 var documentationTemplate = `{{range .}}{{if .Short}}{{.Short | capitalize}}

 {{end}}{{if .Runnable}}Usage:

 	gotext {{.UsageLine}}

 {{end}}{{.Long | trim}}


 {{end}}`

 // commentWriter writes a Go comment to the underlying io.Writer,
 // using line comment form (//).
 type commentWriter struct {
 	W            io.Writer
 	wroteSlashes bool // Wrote "//" at the beginning of the current line.
 }

 func (c *commentWriter) Write(p []byte) (int, error) {
 	var n int
 	for i, b := range p {
 		if !c.wroteSlashes {
 			s := "//"
 			if b != '\n' {
 				s = "// "
 			}
 			if _, err := io.WriteString(c.W, s); err != nil {
 				return n, err
 			}
 			c.wroteSlashes = true
 		}
 		n0, err := c.W.Write(p[i : i+1])
 		n += n0
 		if err != nil {
 			return n, err
 		}
 		if b == '\n' {
 			c.wroteSlashes = false
 		}
 	}
 	return len(p), nil
 }

 // An errWriter wraps a writer, recording whether a write error occurred.
 type errWriter struct {
 	w   io.Writer
 	err error
 }

 func (w *errWriter) Write(b []byte) (int, error) {
 	n, err := w.w.Write(b)
 	if err != nil {
 		w.err = err
 	}
 	return n, err
 }

 // tmpl executes the given template text on data, writing the result to w.
 func tmpl(w io.Writer, text string, data interface{}) {
 	t := template.New("top")
 	t.Funcs(template.FuncMap{"trim": strings.TrimSpace, "capitalize": capitalize})
 	template.Must(t.Parse(text))
 	ew := &errWriter{w: w}
 	err := t.Execute(ew, data)
 	if ew.err != nil {
 		// I/O error writing. Ignore write on closed pipe.
 		if strings.Contains(ew.err.Error(), "pipe") {
 			os.Exit(1)
 		}
 		fatalf("writing output: %v", ew.err)
 	}
 	if err != nil {
 		panic(err)
 	}
 }

 func capitalize(s string) string {
 	if s == "" {
 		return s
 	}
 	r, n := utf8.DecodeRuneInString(s)
 	return string(unicode.ToTitle(r)) + s[n:]
 }

 func printUsage(w io.Writer) {
 	bw := bufio.NewWriter(w)
 	tmpl(bw, usageTemplate, commands)
 	bw.Flush()
 }

 func usage() {
 	printUsage(os.Stderr)
 	os.Exit(2)
 }

 // help implements the 'help' command.
 func help(args []string) {
 	if len(args) == 0 {
 		printUsage(os.Stdout)
 		// not exit 2: succeeded at 'go help'.
 		return
 	}
 	if len(args) != 1 {
 		fmt.Fprintf(os.Stderr, "usage: go help command\n\nToo many arguments given.\n")
 		os.Exit(2) // failed at 'go help'
 	}

 	arg := args[0]

 	// 'go help documentation' generates doc.go.
 	if strings.HasSuffix(arg, "documentation") {
 		w := &bytes.Buffer{}

 		fmt.Fprintln(w, "// Code generated by go generate. DO NOT EDIT.")
 		fmt.Fprintln(w)
 		buf := new(bytes.Buffer)
 		printUsage(buf)
 		usage := &Command{Long: buf.String()}
 		tmpl(&commentWriter{W: w}, documentationTemplate, append([]*Command{usage}, commands...))
 		fmt.Fprintln(w, "package main")
 		if arg == "gendocumentation" {
 			b, err := format.Source(w.Bytes())
 			if err != nil {
 				logf("Could not format generated docs: %v\n", err)
 			}
 			if err := os.WriteFile("doc.go", b, 0666); err != nil {
 				logf("Could not create file alldocs.go: %v\n", err)
 			}
 		} else {
 			fmt.Println(w.String())
 		}
 		return
 	}

 	for _, cmd := range commands {
 		if cmd.Name() == arg {
 			tmpl(os.Stdout, helpTemplate, cmd)
 			// not exit 2: succeeded at 'go help cmd'.
 			return
 		}
 	}

 	fmt.Fprintf(os.Stderr, "Unknown help topic %#q.  Run 'gotext help'.\n", arg)
 	os.Exit(2) // failed at 'go help cmd'
 }

 func getLangs() (tags []language.Tag) {
 	for _, t := range strings.Split(*lang, ",") {
 		if t == "" {
 			continue
 		}
 		tag, err := language.Parse(t)
 		if err != nil {
 			fatalf("gotext: could not parse language %q: %v", t, err)
 		}
 		tags = append(tags, tag)
 	}
 	return tags
 }

 var atexitFuncs []func()

 func atexit(f func()) {
 	atexitFuncs = append(atexitFuncs, f)
 }

 func exit() {
 	for _, f := range atexitFuncs {
 		f()
 	}
 	os.Exit(exitStatus)
 }

 func fatalf(format string, args ...interface{}) {
 	logf(format, args...)
 	exit()
 }

 func logf(format string, args ...interface{}) {
 	log.Printf(format, args...)
 	setExitStatus(1)
 }

 func exitIfErrors() {
 	if exitStatus != 0 {
 		exit()
 	}
 }
	// Copyright 2016 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	//go:generate go build -o gotext.latest
	//go:generate ./gotext.latest help gendocumentation
	//go:generate rm gotext.latest

	package main

	import (
	"bufio"
	"bytes"
	"flag"
	"fmt"
	"go/build"
	"go/format"
	"io"
	"log"
	"os"
	"strings"
	"sync"
	"text/template"
	"unicode"
	"unicode/utf8"

	"golang.org/x/text/message/pipeline"

	"golang.org/x/text/language"
	"golang.org/x/tools/go/buildutil"
	)

	func init() {
	flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc)
	}

	var (
	srcLang = flag.String("srclang", "en-US", "the source-code language")
	dir = flag.String("dir", "locales", "default subdirectory to store translation files")
	)

	func config() (*pipeline.Config, error) {
	tag, err := language.Parse(*srcLang)
	if err != nil {
	return nil, wrap(err, "invalid srclang")
	}
	return &pipeline.Config{
	SourceLanguage: tag,
	Supported: getLangs(),
	TranslationsPattern: `messages\.(.*)\.json$`,
	GenFile: *out,
	}, nil
	}

	// NOTE: the Command struct is copied from the go tool in core.

	// A Command is an implementation of a go command
	// like go build or go fix.
	type Command struct {
	// Run runs the command.
	// The args are the arguments after the command name.
	Run func(cmd Command, c pipeline.Config, args []string) error

	// UsageLine is the one-line usage message.
	// The first word in the line is taken to be the command name.
	UsageLine string

	// Short is the short description shown in the 'go help' output.
	Short string

	// Long is the long message shown in the 'go help <this-command>' output.
	Long string

	// Flag is a set of flags specific to this command.
	Flag flag.FlagSet
	}

	// Name returns the command's name: the first word in the usage line.
	func (c *Command) Name() string {
	name := c.UsageLine
	i := strings.Index(name, " ")
	if i >= 0 {
	name = name[:i]
	}
	return name
	}

	func (c *Command) Usage() {
	fmt.Fprintf(os.Stderr, "usage: %s\n\n", c.UsageLine)
	fmt.Fprintf(os.Stderr, "%s\n", strings.TrimSpace(c.Long))
	os.Exit(2)
	}

	// Runnable reports whether the command can be run; otherwise
	// it is a documentation pseudo-command such as importpath.
	func (c *Command) Runnable() bool {
	return c.Run != nil
	}

	// Commands lists the available commands and help topics.
	// The order here is the order in which they are printed by 'go help'.
	var commands = []*Command{
	cmdUpdate,
	cmdExtract,
	cmdRewrite,
	cmdGenerate,
	// TODO:
	// - update: full-cycle update of extraction, sending, and integration
	// - report: report of freshness of translations
	}

	var exitStatus = 0
	var exitMu sync.Mutex

	func setExitStatus(n int) {
	exitMu.Lock()
	if exitStatus < n {
	exitStatus = n
	}
	exitMu.Unlock()
	}

	var origEnv []string

	func main() {
	flag.Usage = usage
	flag.Parse()
	log.SetFlags(0)

	args := flag.Args()
	if len(args) < 1 {
	usage()
	}

	if args[0] == "help" {
	help(args[1:])
	return
	}

	for _, cmd := range commands {
	if cmd.Name() == args[0] && cmd.Runnable() {
	cmd.Flag.Usage = func() { cmd.Usage() }
	cmd.Flag.Parse(args[1:])
	args = cmd.Flag.Args()
	config, err := config()
	if err != nil {
	fatalf("gotext: %+v", err)
	}
	if err := cmd.Run(cmd, config, args); err != nil {
	fatalf("gotext: %+v", err)
	}
	exit()
	return
	}
	}

	fmt.Fprintf(os.Stderr, "gotext: unknown subcommand %q\nRun 'go help' for usage.\n", args[0])
	setExitStatus(2)
	exit()
	}

	var usageTemplate = `gotext is a tool for managing text in Go source code.

	Usage:

	gotext command [arguments]

	The commands are:
	{{range .}}{{if .Runnable}}
	{{.Name \| printf "%-11s"}} {{.Short}}{{end}}{{end}}

	Use "gotext help [command]" for more information about a command.

	Additional help topics:
	{{range .}}{{if not .Runnable}}
	{{.Name \| printf "%-11s"}} {{.Short}}{{end}}{{end}}

	Use "gotext help [topic]" for more information about that topic.

	`

	var helpTemplate = `{{if .Runnable}}usage: gotext {{.UsageLine}}

	{{end}}{{.Long \| trim}}
	`

	var documentationTemplate = `{{range .}}{{if .Short}}{{.Short \| capitalize}}

	{{end}}{{if .Runnable}}Usage:

	gotext {{.UsageLine}}

	{{end}}{{.Long \| trim}}


	{{end}}`

	// commentWriter writes a Go comment to the underlying io.Writer,
	// using line comment form (//).
	type commentWriter struct {
	W io.Writer
	wroteSlashes bool // Wrote "//" at the beginning of the current line.
	}

	func (c *commentWriter) Write(p []byte) (int, error) {
	var n int
	for i, b := range p {
	if !c.wroteSlashes {
	s := "//"
	if b != '\n' {
	s = "// "
	}
	if _, err := io.WriteString(c.W, s); err != nil {
	return n, err
	}
	c.wroteSlashes = true
	}
	n0, err := c.W.Write(p[i : i+1])
	n += n0
	if err != nil {
	return n, err
	}
	if b == '\n' {
	c.wroteSlashes = false
	}
	}
	return len(p), nil
	}

	// An errWriter wraps a writer, recording whether a write error occurred.
	type errWriter struct {
	w io.Writer
	err error
	}

	func (w *errWriter) Write(b []byte) (int, error) {
	n, err := w.w.Write(b)
	if err != nil {
	w.err = err
	}
	return n, err
	}

	// tmpl executes the given template text on data, writing the result to w.
	func tmpl(w io.Writer, text string, data interface{}) {
	t := template.New("top")
	t.Funcs(template.FuncMap{"trim": strings.TrimSpace, "capitalize": capitalize})
	template.Must(t.Parse(text))
	ew := &errWriter{w: w}
	err := t.Execute(ew, data)
	if ew.err != nil {
	// I/O error writing. Ignore write on closed pipe.
	if strings.Contains(ew.err.Error(), "pipe") {
	os.Exit(1)
	}
	fatalf("writing output: %v", ew.err)
	}
	if err != nil {
	panic(err)
	}
	}

	func capitalize(s string) string {
	if s == "" {
	return s
	}
	r, n := utf8.DecodeRuneInString(s)
	return string(unicode.ToTitle(r)) + s[n:]
	}

	func printUsage(w io.Writer) {
	bw := bufio.NewWriter(w)
	tmpl(bw, usageTemplate, commands)
	bw.Flush()
	}

	func usage() {
	printUsage(os.Stderr)
	os.Exit(2)
	}

	// help implements the 'help' command.
	func help(args []string) {
	if len(args) == 0 {
	printUsage(os.Stdout)
	// not exit 2: succeeded at 'go help'.
	return
	}
	if len(args) != 1 {
	fmt.Fprintf(os.Stderr, "usage: go help command\n\nToo many arguments given.\n")
	os.Exit(2) // failed at 'go help'
	}

	arg := args[0]

	// 'go help documentation' generates doc.go.
	if strings.HasSuffix(arg, "documentation") {
	w := &bytes.Buffer{}

	fmt.Fprintln(w, "// Code generated by go generate. DO NOT EDIT.")
	fmt.Fprintln(w)
	buf := new(bytes.Buffer)
	printUsage(buf)
	usage := &Command{Long: buf.String()}
	tmpl(&commentWriter{W: w}, documentationTemplate, append([]*Command{usage}, commands...))
	fmt.Fprintln(w, "package main")
	if arg == "gendocumentation" {
	b, err := format.Source(w.Bytes())
	if err != nil {
	logf("Could not format generated docs: %v\n", err)
	}
	if err := os.WriteFile("doc.go", b, 0666); err != nil {
	logf("Could not create file alldocs.go: %v\n", err)
	}
	} else {
	fmt.Println(w.String())
	}
	return
	}

	for _, cmd := range commands {
	if cmd.Name() == arg {
	tmpl(os.Stdout, helpTemplate, cmd)
	// not exit 2: succeeded at 'go help cmd'.
	return
	}
	}

	fmt.Fprintf(os.Stderr, "Unknown help topic %#q. Run 'gotext help'.\n", arg)
	os.Exit(2) // failed at 'go help cmd'
	}

	func getLangs() (tags []language.Tag) {
	for _, t := range strings.Split(*lang, ",") {
	if t == "" {
	continue
	}
	tag, err := language.Parse(t)
	if err != nil {
	fatalf("gotext: could not parse language %q: %v", t, err)
	}
	tags = append(tags, tag)
	}
	return tags
	}

	var atexitFuncs []func()

	func atexit(f func()) {
	atexitFuncs = append(atexitFuncs, f)
	}

	func exit() {
	for _, f := range atexitFuncs {
	f()
	}
	os.Exit(exitStatus)
	}

	func fatalf(format string, args ...interface{}) {
	logf(format, args...)
	exit()
	}

	func logf(format string, args ...interface{}) {
	log.Printf(format, args...)
	setExitStatus(1)
	}

	func exitIfErrors() {
	if exitStatus != 0 {
	exit()
	}
	}