internal/number/gen.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.

 // +build ignore

 package main

 import (
 	"flag"
 	"fmt"
 	"log"
 	"reflect"
 	"strings"
 	"unicode/utf8"

 	"golang.org/x/text/internal/gen"
 	"golang.org/x/text/internal/language"
 	"golang.org/x/text/internal/language/compact"
 	"golang.org/x/text/internal/number"
 	"golang.org/x/text/internal/stringset"
 	"golang.org/x/text/unicode/cldr"
 )

 var (
 	test = flag.Bool("test", false,
 		"test existing tables; can be used to compare web data with package data.")
 	outputFile     = flag.String("output", "tables.go", "output file")
 	outputTestFile = flag.String("testoutput", "data_test.go", "output file")

 	draft = flag.String("draft",
 		"contributed",
 		`Minimal draft requirements (approved, contributed, provisional, unconfirmed).`)
 )

 func main() {
 	gen.Init()

 	const pkg = "number"

 	gen.Repackage("gen_common.go", "common.go", pkg)
 	// Read the CLDR zip file.
 	r := gen.OpenCLDRCoreZip()
 	defer r.Close()

 	d := &cldr.Decoder{}
 	d.SetDirFilter("supplemental", "main")
 	d.SetSectionFilter("numbers", "numberingSystem")
 	data, err := d.DecodeZip(r)
 	if err != nil {
 		log.Fatalf("DecodeZip: %v", err)
 	}

 	w := gen.NewCodeWriter()
 	defer w.WriteGoFile(*outputFile, pkg)

 	fmt.Fprintln(w, `import "golang.org/x/text/internal/stringset"`)

 	gen.WriteCLDRVersion(w)

 	genNumSystem(w, data)
 	genSymbols(w, data)
 	genFormats(w, data)
 }

 var systemMap = map[string]system{"latn": 0}

 func getNumberSystem(str string) system {
 	ns, ok := systemMap[str]
 	if !ok {
 		log.Fatalf("No index for numbering system %q", str)
 	}
 	return ns
 }

 func genNumSystem(w *gen.CodeWriter, data *cldr.CLDR) {
 	numSysData := []systemData{
 		{digitSize: 1, zero: [4]byte{'0'}},
 	}

 	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
 		if len(ns.Digits) == 0 {
 			continue
 		}
 		switch ns.Id {
 		case "latn":
 			// hard-wired
 			continue
 		case "hanidec":
 			// non-consecutive digits: treat as "algorithmic"
 			continue
 		}

 		zero, sz := utf8.DecodeRuneInString(ns.Digits)
 		if ns.Digits[sz-1]+9 > 0xBF { // 1011 1111: highest continuation byte
 			log.Fatalf("Last byte of zero value overflows for %s", ns.Id)
 		}

 		i := rune(0)
 		for _, r := range ns.Digits {
 			// Verify that we can do simple math on the UTF-8 byte sequence
 			// of zero to get the digit.
 			if zero+i != r {
 				// Runes not consecutive.
 				log.Fatalf("Digit %d of %s (%U) is not offset correctly from zero value", i, ns.Id, r)
 			}
 			i++
 		}
 		var x [utf8.UTFMax]byte
 		utf8.EncodeRune(x[:], zero)
 		id := system(len(numSysData))
 		systemMap[ns.Id] = id
 		numSysData = append(numSysData, systemData{
 			id:        id,
 			digitSize: byte(sz),
 			zero:      x,
 		})
 	}
 	w.WriteVar("numSysData", numSysData)

 	algoID := system(len(numSysData))
 	fmt.Fprintln(w, "const (")
 	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
 		id, ok := systemMap[ns.Id]
 		if !ok {
 			id = algoID
 			systemMap[ns.Id] = id
 			algoID++
 		}
 		fmt.Fprintf(w, "num%s = %#x\n", strings.Title(ns.Id), id)
 	}
 	fmt.Fprintln(w, "numNumberSystems")
 	fmt.Fprintln(w, ")")

 	fmt.Fprintln(w, "var systemMap = map[string]system{")
 	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
 		fmt.Fprintf(w, "%q: num%s,\n", ns.Id, strings.Title(ns.Id))
 		w.Size += len(ns.Id) + 16 + 1 // very coarse approximation
 	}
 	fmt.Fprintln(w, "}")
 }

 func genSymbols(w *gen.CodeWriter, data *cldr.CLDR) {
 	d, err := cldr.ParseDraft(*draft)
 	if err != nil {
 		log.Fatalf("invalid draft level: %v", err)
 	}

 	nNumberSystems := system(len(systemMap))

 	type symbols [NumSymbolTypes]string

 	type key struct {
 		tag    compact.ID
 		system system
 	}
 	symbolMap := map[key]*symbols{}

 	defaults := map[compact.ID]system{}

 	for _, lang := range data.Locales() {
 		ldml := data.RawLDML(lang)
 		if ldml.Numbers == nil {
 			continue
 		}
 		langIndex, ok := compact.FromTag(language.MustParse(lang))
 		if !ok {
 			log.Fatalf("No compact index for language %s", lang)
 		}
 		if d := ldml.Numbers.DefaultNumberingSystem; len(d) > 0 {
 			defaults[langIndex] = getNumberSystem(d[0].Data())
 		}

 		syms := cldr.MakeSlice(&ldml.Numbers.Symbols)
 		syms.SelectDraft(d)

 		getFirst := func(name string, x interface{}) string {
 			v := reflect.ValueOf(x)
 			slice := cldr.MakeSlice(x)
 			slice.SelectAnyOf("alt", "", "alt")
 			if reflect.Indirect(v).Len() == 0 {
 				return ""
 			} else if reflect.Indirect(v).Len() > 1 {
 				log.Fatalf("%s: multiple values of %q within single symbol not supported.", lang, name)
 			}
 			return reflect.Indirect(v).Index(0).MethodByName("Data").Call(nil)[0].String()
 		}

 		for _, sym := range ldml.Numbers.Symbols {
 			if sym.NumberSystem == "" {
 				// This is just linking the default of root to "latn".
 				continue
 			}
 			symbolMap[key{langIndex, getNumberSystem(sym.NumberSystem)}] = &symbols{
 				SymDecimal:                getFirst("decimal", &sym.Decimal),
 				SymGroup:                  getFirst("group", &sym.Group),
 				SymList:                   getFirst("list", &sym.List),
 				SymPercentSign:            getFirst("percentSign", &sym.PercentSign),
 				SymPlusSign:               getFirst("plusSign", &sym.PlusSign),
 				SymMinusSign:              getFirst("minusSign", &sym.MinusSign),
 				SymExponential:            getFirst("exponential", &sym.Exponential),
 				SymSuperscriptingExponent: getFirst("superscriptingExponent", &sym.SuperscriptingExponent),
 				SymPerMille:               getFirst("perMille", &sym.PerMille),
 				SymInfinity:               getFirst("infinity", &sym.Infinity),
 				SymNan:                    getFirst("nan", &sym.Nan),
 				SymTimeSeparator:          getFirst("timeSeparator", &sym.TimeSeparator),
 			}
 		}
 	}

 	// Expand all values.
 	for k, syms := range symbolMap {
 		for t := SymDecimal; t < NumSymbolTypes; t++ {
 			p := k.tag
 			for syms[t] == "" {
 				p = p.Parent()
 				if pSyms, ok := symbolMap[key{p, k.system}]; ok && (*pSyms)[t] != "" {
 					syms[t] = (*pSyms)[t]
 					break
 				}
 				if p == 0 /* und */ {
 					// Default to root, latn.
 					syms[t] = (*symbolMap[key{}])[t]
 				}
 			}
 		}
 	}

 	// Unique the symbol sets and write the string data.
 	m := map[symbols]int{}
 	sb := stringset.NewBuilder()

 	symIndex := [][NumSymbolTypes]byte{}

 	for ns := system(0); ns < nNumberSystems; ns++ {
 		for _, l := range data.Locales() {
 			langIndex, _ := compact.FromTag(language.MustParse(l))
 			s := symbolMap[key{langIndex, ns}]
 			if s == nil {
 				continue
 			}
 			if _, ok := m[*s]; !ok {
 				m[*s] = len(symIndex)
 				sb.Add(s[:]...)
 				var x [NumSymbolTypes]byte
 				for i := SymDecimal; i < NumSymbolTypes; i++ {
 					x[i] = byte(sb.Index((*s)[i]))
 				}
 				symIndex = append(symIndex, x)
 			}
 		}
 	}
 	w.WriteVar("symIndex", symIndex)
 	w.WriteVar("symData", sb.Set())

 	// resolveSymbolIndex gets the index from the closest matching locale,
 	// including the locale itself.
 	resolveSymbolIndex := func(langIndex compact.ID, ns system) symOffset {
 		for {
 			if sym := symbolMap[key{langIndex, ns}]; sym != nil {
 				return symOffset(m[*sym])
 			}
 			if langIndex == 0 {
 				return 0 // und, latn
 			}
 			langIndex = langIndex.Parent()
 		}
 	}

 	// Create an index with the symbols for each locale for the latn numbering
 	// system. If this is not the default, or the only one, for a locale, we
 	// will overwrite the value later.
 	var langToDefaults [compact.NumCompactTags]symOffset
 	for _, l := range data.Locales() {
 		langIndex, _ := compact.FromTag(language.MustParse(l))
 		langToDefaults[langIndex] = resolveSymbolIndex(langIndex, 0)
 	}

 	// Delete redundant entries.
 	for _, l := range data.Locales() {
 		langIndex, _ := compact.FromTag(language.MustParse(l))
 		def := defaults[langIndex]
 		syms := symbolMap[key{langIndex, def}]
 		if syms == nil {
 			continue
 		}
 		for ns := system(0); ns < nNumberSystems; ns++ {
 			if ns == def {
 				continue
 			}
 			if altSyms, ok := symbolMap[key{langIndex, ns}]; ok && *altSyms == *syms {
 				delete(symbolMap, key{langIndex, ns})
 			}
 		}
 	}

 	// Create a sorted list of alternatives per language. This will only need to
 	// be referenced if a user specified an alternative numbering system.
 	var langToAlt []altSymData
 	for _, l := range data.Locales() {
 		langIndex, _ := compact.FromTag(language.MustParse(l))
 		start := len(langToAlt)
 		if start >= hasNonLatnMask {
 			log.Fatalf("Number of alternative assignments >= %x", hasNonLatnMask)
 		}
 		// Create the entry for the default value.
 		def := defaults[langIndex]
 		langToAlt = append(langToAlt, altSymData{
 			compactTag: langIndex,
 			system:     def,
 			symIndex:   resolveSymbolIndex(langIndex, def),
 		})

 		for ns := system(0); ns < nNumberSystems; ns++ {
 			if def == ns {
 				continue
 			}
 			if sym := symbolMap[key{langIndex, ns}]; sym != nil {
 				langToAlt = append(langToAlt, altSymData{
 					compactTag: langIndex,
 					system:     ns,
 					symIndex:   resolveSymbolIndex(langIndex, ns),
 				})
 			}
 		}
 		if def == 0 && len(langToAlt) == start+1 {
 			// No additional data: erase the entry.
 			langToAlt = langToAlt[:start]
 		} else {
 			// Overwrite the entry in langToDefaults.
 			langToDefaults[langIndex] = hasNonLatnMask | symOffset(start)
 		}
 	}
 	w.WriteComment(`
 langToDefaults maps a compact language index to the default numbering system
 and default symbol set`)
 	w.WriteVar("langToDefaults", langToDefaults)

 	w.WriteComment(`
 langToAlt is a list of numbering system and symbol set pairs, sorted and
 marked by compact language index.`)
 	w.WriteVar("langToAlt", langToAlt)
 }

 // genFormats generates the lookup table for decimal, scientific and percent
 // patterns.
 //
 // CLDR allows for patterns to be different per language for different numbering
 // systems. In practice the patterns are set to be consistent for a language
 // independent of the numbering system. genFormats verifies that no language
 // deviates from this.
 func genFormats(w *gen.CodeWriter, data *cldr.CLDR) {
 	d, err := cldr.ParseDraft(*draft)
 	if err != nil {
 		log.Fatalf("invalid draft level: %v", err)
 	}

 	// Fill the first slot with a dummy so we can identify unspecified tags.
 	formats := []number.Pattern{{}}
 	patterns := map[string]int{}

 	// TODO: It would be possible to eliminate two of these slices by having
 	// another indirection and store a reference to the combination of patterns.
 	decimal := make([]byte, compact.NumCompactTags)
 	scientific := make([]byte, compact.NumCompactTags)
 	percent := make([]byte, compact.NumCompactTags)

 	for _, lang := range data.Locales() {
 		ldml := data.RawLDML(lang)
 		if ldml.Numbers == nil {
 			continue
 		}
 		langIndex, ok := compact.FromTag(language.MustParse(lang))
 		if !ok {
 			log.Fatalf("No compact index for language %s", lang)
 		}
 		type patternSlice []*struct {
 			cldr.Common
 			Numbers string `xml:"numbers,attr"`
 			Count   string `xml:"count,attr"`
 		}

 		add := func(name string, tags []byte, ps patternSlice) {
 			sl := cldr.MakeSlice(&ps)
 			sl.SelectDraft(d)
 			if len(ps) == 0 {
 				return
 			}
 			if len(ps) > 2 || len(ps) == 2 && ps[0] != ps[1] {
 				log.Fatalf("Inconsistent %d patterns for language %s", name, lang)
 			}
 			s := ps[0].Data()

 			index, ok := patterns[s]
 			if !ok {
 				nf, err := number.ParsePattern(s)
 				if err != nil {
 					log.Fatal(err)
 				}
 				index = len(formats)
 				patterns[s] = index
 				formats = append(formats, *nf)
 			}
 			tags[langIndex] = byte(index)
 		}

 		for _, df := range ldml.Numbers.DecimalFormats {
 			for _, l := range df.DecimalFormatLength {
 				if l.Type != "" {
 					continue
 				}
 				for _, f := range l.DecimalFormat {
 					add("decimal", decimal, f.Pattern)
 				}
 			}
 		}
 		for _, df := range ldml.Numbers.ScientificFormats {
 			for _, l := range df.ScientificFormatLength {
 				if l.Type != "" {
 					continue
 				}
 				for _, f := range l.ScientificFormat {
 					add("scientific", scientific, f.Pattern)
 				}
 			}
 		}
 		for _, df := range ldml.Numbers.PercentFormats {
 			for _, l := range df.PercentFormatLength {
 				if l.Type != "" {
 					continue
 				}
 				for _, f := range l.PercentFormat {
 					add("percent", percent, f.Pattern)
 				}
 			}
 		}
 	}

 	// Complete the parent tag array to reflect inheritance. An index of 0
 	// indicates an unspecified value.
 	for _, data := range [][]byte{decimal, scientific, percent} {
 		for i := range data {
 			p := compact.ID(i)
 			for ; data[p] == 0; p = p.Parent() {
 			}
 			data[i] = data[p]
 		}
 	}
 	w.WriteVar("tagToDecimal", decimal)
 	w.WriteVar("tagToScientific", scientific)
 	w.WriteVar("tagToPercent", percent)

 	value := strings.Replace(fmt.Sprintf("%#v", formats), "number.", "", -1)
 	// Break up the lines. This won't give ideal perfect formatting, but it is
 	// better than one huge line.
 	value = strings.Replace(value, ", ", ",\n", -1)
 	fmt.Fprintf(w, "var formats = %s\n", value)
 }
	// 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.

	// +build ignore

	package main

	import (
	"flag"
	"fmt"
	"log"
	"reflect"
	"strings"
	"unicode/utf8"

	"golang.org/x/text/internal/gen"
	"golang.org/x/text/internal/language"
	"golang.org/x/text/internal/language/compact"
	"golang.org/x/text/internal/number"
	"golang.org/x/text/internal/stringset"
	"golang.org/x/text/unicode/cldr"
	)

	var (
	test = flag.Bool("test", false,
	"test existing tables; can be used to compare web data with package data.")
	outputFile = flag.String("output", "tables.go", "output file")
	outputTestFile = flag.String("testoutput", "data_test.go", "output file")

	draft = flag.String("draft",
	"contributed",
	`Minimal draft requirements (approved, contributed, provisional, unconfirmed).`)
	)

	func main() {
	gen.Init()

	const pkg = "number"

	gen.Repackage("gen_common.go", "common.go", pkg)
	// Read the CLDR zip file.
	r := gen.OpenCLDRCoreZip()
	defer r.Close()

	d := &cldr.Decoder{}
	d.SetDirFilter("supplemental", "main")
	d.SetSectionFilter("numbers", "numberingSystem")
	data, err := d.DecodeZip(r)
	if err != nil {
	log.Fatalf("DecodeZip: %v", err)
	}

	w := gen.NewCodeWriter()
	defer w.WriteGoFile(*outputFile, pkg)

	fmt.Fprintln(w, `import "golang.org/x/text/internal/stringset"`)

	gen.WriteCLDRVersion(w)

	genNumSystem(w, data)
	genSymbols(w, data)
	genFormats(w, data)
	}

	var systemMap = map[string]system{"latn": 0}

	func getNumberSystem(str string) system {
	ns, ok := systemMap[str]
	if !ok {
	log.Fatalf("No index for numbering system %q", str)
	}
	return ns
	}

	func genNumSystem(w gen.CodeWriter, data cldr.CLDR) {
	numSysData := []systemData{
	{digitSize: 1, zero: [4]byte{'0'}},
	}

	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
	if len(ns.Digits) == 0 {
	continue
	}
	switch ns.Id {
	case "latn":
	// hard-wired
	continue
	case "hanidec":
	// non-consecutive digits: treat as "algorithmic"
	continue
	}

	zero, sz := utf8.DecodeRuneInString(ns.Digits)
	if ns.Digits[sz-1]+9 > 0xBF { // 1011 1111: highest continuation byte
	log.Fatalf("Last byte of zero value overflows for %s", ns.Id)
	}

	i := rune(0)
	for _, r := range ns.Digits {
	// Verify that we can do simple math on the UTF-8 byte sequence
	// of zero to get the digit.
	if zero+i != r {
	// Runes not consecutive.
	log.Fatalf("Digit %d of %s (%U) is not offset correctly from zero value", i, ns.Id, r)
	}
	i++
	}
	var x [utf8.UTFMax]byte
	utf8.EncodeRune(x[:], zero)
	id := system(len(numSysData))
	systemMap[ns.Id] = id
	numSysData = append(numSysData, systemData{
	id: id,
	digitSize: byte(sz),
	zero: x,
	})
	}
	w.WriteVar("numSysData", numSysData)

	algoID := system(len(numSysData))
	fmt.Fprintln(w, "const (")
	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
	id, ok := systemMap[ns.Id]
	if !ok {
	id = algoID
	systemMap[ns.Id] = id
	algoID++
	}
	fmt.Fprintf(w, "num%s = %#x\n", strings.Title(ns.Id), id)
	}
	fmt.Fprintln(w, "numNumberSystems")
	fmt.Fprintln(w, ")")

	fmt.Fprintln(w, "var systemMap = map[string]system{")
	for _, ns := range data.Supplemental().NumberingSystems.NumberingSystem {
	fmt.Fprintf(w, "%q: num%s,\n", ns.Id, strings.Title(ns.Id))
	w.Size += len(ns.Id) + 16 + 1 // very coarse approximation
	}
	fmt.Fprintln(w, "}")
	}

	func genSymbols(w gen.CodeWriter, data cldr.CLDR) {
	d, err := cldr.ParseDraft(*draft)
	if err != nil {
	log.Fatalf("invalid draft level: %v", err)
	}

	nNumberSystems := system(len(systemMap))

	type symbols [NumSymbolTypes]string

	type key struct {
	tag compact.ID
	system system
	}
	symbolMap := map[key]*symbols{}

	defaults := map[compact.ID]system{}

	for _, lang := range data.Locales() {
	ldml := data.RawLDML(lang)
	if ldml.Numbers == nil {
	continue
	}
	langIndex, ok := compact.FromTag(language.MustParse(lang))
	if !ok {
	log.Fatalf("No compact index for language %s", lang)
	}
	if d := ldml.Numbers.DefaultNumberingSystem; len(d) > 0 {
	defaults[langIndex] = getNumberSystem(d[0].Data())
	}

	syms := cldr.MakeSlice(&ldml.Numbers.Symbols)
	syms.SelectDraft(d)

	getFirst := func(name string, x interface{}) string {
	v := reflect.ValueOf(x)
	slice := cldr.MakeSlice(x)
	slice.SelectAnyOf("alt", "", "alt")
	if reflect.Indirect(v).Len() == 0 {
	return ""
	} else if reflect.Indirect(v).Len() > 1 {
	log.Fatalf("%s: multiple values of %q within single symbol not supported.", lang, name)
	}
	return reflect.Indirect(v).Index(0).MethodByName("Data").Call(nil)[0].String()
	}

	for _, sym := range ldml.Numbers.Symbols {
	if sym.NumberSystem == "" {
	// This is just linking the default of root to "latn".
	continue
	}
	symbolMap[key{langIndex, getNumberSystem(sym.NumberSystem)}] = &symbols{
	SymDecimal: getFirst("decimal", &sym.Decimal),
	SymGroup: getFirst("group", &sym.Group),
	SymList: getFirst("list", &sym.List),
	SymPercentSign: getFirst("percentSign", &sym.PercentSign),
	SymPlusSign: getFirst("plusSign", &sym.PlusSign),
	SymMinusSign: getFirst("minusSign", &sym.MinusSign),
	SymExponential: getFirst("exponential", &sym.Exponential),
	SymSuperscriptingExponent: getFirst("superscriptingExponent", &sym.SuperscriptingExponent),
	SymPerMille: getFirst("perMille", &sym.PerMille),
	SymInfinity: getFirst("infinity", &sym.Infinity),
	SymNan: getFirst("nan", &sym.Nan),
	SymTimeSeparator: getFirst("timeSeparator", &sym.TimeSeparator),
	}
	}
	}

	// Expand all values.
	for k, syms := range symbolMap {
	for t := SymDecimal; t < NumSymbolTypes; t++ {
	p := k.tag
	for syms[t] == "" {
	p = p.Parent()
	if pSyms, ok := symbolMap[key{p, k.system}]; ok && (*pSyms)[t] != "" {
	syms[t] = (*pSyms)[t]
	break
	}
	if p == 0 /* und */ {
	// Default to root, latn.
	syms[t] = (*symbolMap[key{}])[t]
	}
	}
	}
	}

	// Unique the symbol sets and write the string data.
	m := map[symbols]int{}
	sb := stringset.NewBuilder()

	symIndex := [][NumSymbolTypes]byte{}

	for ns := system(0); ns < nNumberSystems; ns++ {
	for _, l := range data.Locales() {
	langIndex, _ := compact.FromTag(language.MustParse(l))
	s := symbolMap[key{langIndex, ns}]
	if s == nil {
	continue
	}
	if _, ok := m[*s]; !ok {
	m[*s] = len(symIndex)
	sb.Add(s[:]...)
	var x [NumSymbolTypes]byte
	for i := SymDecimal; i < NumSymbolTypes; i++ {
	x[i] = byte(sb.Index((*s)[i]))
	}
	symIndex = append(symIndex, x)
	}
	}
	}
	w.WriteVar("symIndex", symIndex)
	w.WriteVar("symData", sb.Set())

	// resolveSymbolIndex gets the index from the closest matching locale,
	// including the locale itself.
	resolveSymbolIndex := func(langIndex compact.ID, ns system) symOffset {
	for {
	if sym := symbolMap[key{langIndex, ns}]; sym != nil {
	return symOffset(m[*sym])
	}
	if langIndex == 0 {
	return 0 // und, latn
	}
	langIndex = langIndex.Parent()
	}
	}

	// Create an index with the symbols for each locale for the latn numbering
	// system. If this is not the default, or the only one, for a locale, we
	// will overwrite the value later.
	var langToDefaults [compact.NumCompactTags]symOffset
	for _, l := range data.Locales() {
	langIndex, _ := compact.FromTag(language.MustParse(l))
	langToDefaults[langIndex] = resolveSymbolIndex(langIndex, 0)
	}

	// Delete redundant entries.
	for _, l := range data.Locales() {
	langIndex, _ := compact.FromTag(language.MustParse(l))
	def := defaults[langIndex]
	syms := symbolMap[key{langIndex, def}]
	if syms == nil {
	continue
	}
	for ns := system(0); ns < nNumberSystems; ns++ {
	if ns == def {
	continue
	}
	if altSyms, ok := symbolMap[key{langIndex, ns}]; ok && altSyms == syms {
	delete(symbolMap, key{langIndex, ns})
	}
	}
	}

	// Create a sorted list of alternatives per language. This will only need to
	// be referenced if a user specified an alternative numbering system.
	var langToAlt []altSymData
	for _, l := range data.Locales() {
	langIndex, _ := compact.FromTag(language.MustParse(l))
	start := len(langToAlt)
	if start >= hasNonLatnMask {
	log.Fatalf("Number of alternative assignments >= %x", hasNonLatnMask)
	}
	// Create the entry for the default value.
	def := defaults[langIndex]
	langToAlt = append(langToAlt, altSymData{
	compactTag: langIndex,
	system: def,
	symIndex: resolveSymbolIndex(langIndex, def),
	})

	for ns := system(0); ns < nNumberSystems; ns++ {
	if def == ns {
	continue
	}
	if sym := symbolMap[key{langIndex, ns}]; sym != nil {
	langToAlt = append(langToAlt, altSymData{
	compactTag: langIndex,
	system: ns,
	symIndex: resolveSymbolIndex(langIndex, ns),
	})
	}
	}
	if def == 0 && len(langToAlt) == start+1 {
	// No additional data: erase the entry.
	langToAlt = langToAlt[:start]
	} else {
	// Overwrite the entry in langToDefaults.
	langToDefaults[langIndex] = hasNonLatnMask \| symOffset(start)
	}
	}
	w.WriteComment(`
	langToDefaults maps a compact language index to the default numbering system
	and default symbol set`)
	w.WriteVar("langToDefaults", langToDefaults)

	w.WriteComment(`
	langToAlt is a list of numbering system and symbol set pairs, sorted and
	marked by compact language index.`)
	w.WriteVar("langToAlt", langToAlt)
	}

	// genFormats generates the lookup table for decimal, scientific and percent
	// patterns.
	//
	// CLDR allows for patterns to be different per language for different numbering
	// systems. In practice the patterns are set to be consistent for a language
	// independent of the numbering system. genFormats verifies that no language
	// deviates from this.
	func genFormats(w gen.CodeWriter, data cldr.CLDR) {
	d, err := cldr.ParseDraft(*draft)
	if err != nil {
	log.Fatalf("invalid draft level: %v", err)
	}

	// Fill the first slot with a dummy so we can identify unspecified tags.
	formats := []number.Pattern{{}}
	patterns := map[string]int{}

	// TODO: It would be possible to eliminate two of these slices by having
	// another indirection and store a reference to the combination of patterns.
	decimal := make([]byte, compact.NumCompactTags)
	scientific := make([]byte, compact.NumCompactTags)
	percent := make([]byte, compact.NumCompactTags)

	for _, lang := range data.Locales() {
	ldml := data.RawLDML(lang)
	if ldml.Numbers == nil {
	continue
	}
	langIndex, ok := compact.FromTag(language.MustParse(lang))
	if !ok {
	log.Fatalf("No compact index for language %s", lang)
	}
	type patternSlice []*struct {
	cldr.Common
	Numbers string `xml:"numbers,attr"`
	Count string `xml:"count,attr"`
	}

	add := func(name string, tags []byte, ps patternSlice) {
	sl := cldr.MakeSlice(&ps)
	sl.SelectDraft(d)
	if len(ps) == 0 {
	return
	}
	if len(ps) > 2 \|\| len(ps) == 2 && ps[0] != ps[1] {
	log.Fatalf("Inconsistent %d patterns for language %s", name, lang)
	}
	s := ps[0].Data()

	index, ok := patterns[s]
	if !ok {
	nf, err := number.ParsePattern(s)
	if err != nil {
	log.Fatal(err)
	}
	index = len(formats)
	patterns[s] = index
	formats = append(formats, *nf)
	}
	tags[langIndex] = byte(index)
	}

	for _, df := range ldml.Numbers.DecimalFormats {
	for _, l := range df.DecimalFormatLength {
	if l.Type != "" {
	continue
	}
	for _, f := range l.DecimalFormat {
	add("decimal", decimal, f.Pattern)
	}
	}
	}
	for _, df := range ldml.Numbers.ScientificFormats {
	for _, l := range df.ScientificFormatLength {
	if l.Type != "" {
	continue
	}
	for _, f := range l.ScientificFormat {
	add("scientific", scientific, f.Pattern)
	}
	}
	}
	for _, df := range ldml.Numbers.PercentFormats {
	for _, l := range df.PercentFormatLength {
	if l.Type != "" {
	continue
	}
	for _, f := range l.PercentFormat {
	add("percent", percent, f.Pattern)
	}
	}
	}
	}

	// Complete the parent tag array to reflect inheritance. An index of 0
	// indicates an unspecified value.
	for _, data := range [][]byte{decimal, scientific, percent} {
	for i := range data {
	p := compact.ID(i)
	for ; data[p] == 0; p = p.Parent() {
	}
	data[i] = data[p]
	}
	}
	w.WriteVar("tagToDecimal", decimal)
	w.WriteVar("tagToScientific", scientific)
	w.WriteVar("tagToPercent", percent)

	value := strings.Replace(fmt.Sprintf("%#v", formats), "number.", "", -1)
	// Break up the lines. This won't give ideal perfect formatting, but it is
	// better than one huge line.
	value = strings.Replace(value, ", ", ",\n", -1)
	fmt.Fprintf(w, "var formats = %s\n", value)
	}