--- /dev/null
+// Copyright 2013 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 run gen.go gen_common.go -output tables.go
+
+package language // import "golang.org/x/text/internal/language"
+
+// TODO: Remove above NOTE after:
+// - verifying that tables are dropped correctly (most notably matcher tables).
+
+import (
+ "errors"
+ "fmt"
+ "strings"
+)
+
+const (
+ // maxCoreSize is the maximum size of a BCP 47 tag without variants and
+ // extensions. Equals max lang (3) + script (4) + max reg (3) + 2 dashes.
+ maxCoreSize = 12
+
+ // max99thPercentileSize is a somewhat arbitrary buffer size that presumably
+ // is large enough to hold at least 99% of the BCP 47 tags.
+ max99thPercentileSize = 32
+
+ // maxSimpleUExtensionSize is the maximum size of a -u extension with one
+ // key-type pair. Equals len("-u-") + key (2) + dash + max value (8).
+ maxSimpleUExtensionSize = 14
+)
+
+// Tag represents a BCP 47 language tag. It is used to specify an instance of a
+// specific language or locale. All language tag values are guaranteed to be
+// well-formed. The zero value of Tag is Und.
+type Tag struct {
+ // TODO: the following fields have the form TagTypeID. This name is chosen
+ // to allow refactoring the public package without conflicting with its
+ // Base, Script, and Region methods. Once the transition is fully completed
+ // the ID can be stripped from the name.
+
+ LangID Language
+ RegionID Region
+ // TODO: we will soon run out of positions for ScriptID. Idea: instead of
+ // storing lang, region, and ScriptID codes, store only the compact index and
+ // have a lookup table from this code to its expansion. This greatly speeds
+ // up table lookup, speed up common variant cases.
+ // This will also immediately free up 3 extra bytes. Also, the pVariant
+ // field can now be moved to the lookup table, as the compact index uniquely
+ // determines the offset of a possible variant.
+ ScriptID Script
+ pVariant byte // offset in str, includes preceding '-'
+ pExt uint16 // offset of first extension, includes preceding '-'
+
+ // str is the string representation of the Tag. It will only be used if the
+ // tag has variants or extensions.
+ str string
+}
+
+// Make is a convenience wrapper for Parse that omits the error.
+// In case of an error, a sensible default is returned.
+func Make(s string) Tag {
+ t, _ := Parse(s)
+ return t
+}
+
+// Raw returns the raw base language, script and region, without making an
+// attempt to infer their values.
+// TODO: consider removing
+func (t Tag) Raw() (b Language, s Script, r Region) {
+ return t.LangID, t.ScriptID, t.RegionID
+}
+
+// equalTags compares language, script and region subtags only.
+func (t Tag) equalTags(a Tag) bool {
+ return t.LangID == a.LangID && t.ScriptID == a.ScriptID && t.RegionID == a.RegionID
+}
+
+// IsRoot returns true if t is equal to language "und".
+func (t Tag) IsRoot() bool {
+ if int(t.pVariant) < len(t.str) {
+ return false
+ }
+ return t.equalTags(Und)
+}
+
+// IsPrivateUse reports whether the Tag consists solely of an IsPrivateUse use
+// tag.
+func (t Tag) IsPrivateUse() bool {
+ return t.str != "" && t.pVariant == 0
+}
+
+// RemakeString is used to update t.str in case lang, script or region changed.
+// It is assumed that pExt and pVariant still point to the start of the
+// respective parts.
+func (t *Tag) RemakeString() {
+ if t.str == "" {
+ return
+ }
+ extra := t.str[t.pVariant:]
+ if t.pVariant > 0 {
+ extra = extra[1:]
+ }
+ if t.equalTags(Und) && strings.HasPrefix(extra, "x-") {
+ t.str = extra
+ t.pVariant = 0
+ t.pExt = 0
+ return
+ }
+ var buf [max99thPercentileSize]byte // avoid extra memory allocation in most cases.
+ b := buf[:t.genCoreBytes(buf[:])]
+ if extra != "" {
+ diff := len(b) - int(t.pVariant)
+ b = append(b, '-')
+ b = append(b, extra...)
+ t.pVariant = uint8(int(t.pVariant) + diff)
+ t.pExt = uint16(int(t.pExt) + diff)
+ } else {
+ t.pVariant = uint8(len(b))
+ t.pExt = uint16(len(b))
+ }
+ t.str = string(b)
+}
+
+// genCoreBytes writes a string for the base languages, script and region tags
+// to the given buffer and returns the number of bytes written. It will never
+// write more than maxCoreSize bytes.
+func (t *Tag) genCoreBytes(buf []byte) int {
+ n := t.LangID.StringToBuf(buf[:])
+ if t.ScriptID != 0 {
+ n += copy(buf[n:], "-")
+ n += copy(buf[n:], t.ScriptID.String())
+ }
+ if t.RegionID != 0 {
+ n += copy(buf[n:], "-")
+ n += copy(buf[n:], t.RegionID.String())
+ }
+ return n
+}
+
+// String returns the canonical string representation of the language tag.
+func (t Tag) String() string {
+ if t.str != "" {
+ return t.str
+ }
+ if t.ScriptID == 0 && t.RegionID == 0 {
+ return t.LangID.String()
+ }
+ buf := [maxCoreSize]byte{}
+ return string(buf[:t.genCoreBytes(buf[:])])
+}
+
+// MarshalText implements encoding.TextMarshaler.
+func (t Tag) MarshalText() (text []byte, err error) {
+ if t.str != "" {
+ text = append(text, t.str...)
+ } else if t.ScriptID == 0 && t.RegionID == 0 {
+ text = append(text, t.LangID.String()...)
+ } else {
+ buf := [maxCoreSize]byte{}
+ text = buf[:t.genCoreBytes(buf[:])]
+ }
+ return text, nil
+}
+
+// UnmarshalText implements encoding.TextUnmarshaler.
+func (t *Tag) UnmarshalText(text []byte) error {
+ tag, err := Parse(string(text))
+ *t = tag
+ return err
+}
+
+// Variants returns the part of the tag holding all variants or the empty string
+// if there are no variants defined.
+func (t Tag) Variants() string {
+ if t.pVariant == 0 {
+ return ""
+ }
+ return t.str[t.pVariant:t.pExt]
+}
+
+// VariantOrPrivateUseTags returns variants or private use tags.
+func (t Tag) VariantOrPrivateUseTags() string {
+ if t.pExt > 0 {
+ return t.str[t.pVariant:t.pExt]
+ }
+ return t.str[t.pVariant:]
+}
+
+// HasString reports whether this tag defines more than just the raw
+// components.
+func (t Tag) HasString() bool {
+ return t.str != ""
+}
+
+// Parent returns the CLDR parent of t. In CLDR, missing fields in data for a
+// specific language are substituted with fields from the parent language.
+// The parent for a language may change for newer versions of CLDR.
+func (t Tag) Parent() Tag {
+ if t.str != "" {
+ // Strip the variants and extensions.
+ b, s, r := t.Raw()
+ t = Tag{LangID: b, ScriptID: s, RegionID: r}
+ if t.RegionID == 0 && t.ScriptID != 0 && t.LangID != 0 {
+ base, _ := addTags(Tag{LangID: t.LangID})
+ if base.ScriptID == t.ScriptID {
+ return Tag{LangID: t.LangID}
+ }
+ }
+ return t
+ }
+ if t.LangID != 0 {
+ if t.RegionID != 0 {
+ maxScript := t.ScriptID
+ if maxScript == 0 {
+ max, _ := addTags(t)
+ maxScript = max.ScriptID
+ }
+
+ for i := range parents {
+ if Language(parents[i].lang) == t.LangID && Script(parents[i].maxScript) == maxScript {
+ for _, r := range parents[i].fromRegion {
+ if Region(r) == t.RegionID {
+ return Tag{
+ LangID: t.LangID,
+ ScriptID: Script(parents[i].script),
+ RegionID: Region(parents[i].toRegion),
+ }
+ }
+ }
+ }
+ }
+
+ // Strip the script if it is the default one.
+ base, _ := addTags(Tag{LangID: t.LangID})
+ if base.ScriptID != maxScript {
+ return Tag{LangID: t.LangID, ScriptID: maxScript}
+ }
+ return Tag{LangID: t.LangID}
+ } else if t.ScriptID != 0 {
+ // The parent for an base-script pair with a non-default script is
+ // "und" instead of the base language.
+ base, _ := addTags(Tag{LangID: t.LangID})
+ if base.ScriptID != t.ScriptID {
+ return Und
+ }
+ return Tag{LangID: t.LangID}
+ }
+ }
+ return Und
+}
+
+// ParseExtension parses s as an extension and returns it on success.
+func ParseExtension(s string) (ext string, err error) {
+ scan := makeScannerString(s)
+ var end int
+ if n := len(scan.token); n != 1 {
+ return "", ErrSyntax
+ }
+ scan.toLower(0, len(scan.b))
+ end = parseExtension(&scan)
+ if end != len(s) {
+ return "", ErrSyntax
+ }
+ return string(scan.b), nil
+}
+
+// HasVariants reports whether t has variants.
+func (t Tag) HasVariants() bool {
+ return uint16(t.pVariant) < t.pExt
+}
+
+// HasExtensions reports whether t has extensions.
+func (t Tag) HasExtensions() bool {
+ return int(t.pExt) < len(t.str)
+}
+
+// Extension returns the extension of type x for tag t. It will return
+// false for ok if t does not have the requested extension. The returned
+// extension will be invalid in this case.
+func (t Tag) Extension(x byte) (ext string, ok bool) {
+ for i := int(t.pExt); i < len(t.str)-1; {
+ var ext string
+ i, ext = getExtension(t.str, i)
+ if ext[0] == x {
+ return ext, true
+ }
+ }
+ return "", false
+}
+
+// Extensions returns all extensions of t.
+func (t Tag) Extensions() []string {
+ e := []string{}
+ for i := int(t.pExt); i < len(t.str)-1; {
+ var ext string
+ i, ext = getExtension(t.str, i)
+ e = append(e, ext)
+ }
+ return e
+}
+
+// TypeForKey returns the type associated with the given key, where key and type
+// are of the allowed values defined for the Unicode locale extension ('u') in
+// https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
+// TypeForKey will traverse the inheritance chain to get the correct value.
+func (t Tag) TypeForKey(key string) string {
+ if start, end, _ := t.findTypeForKey(key); end != start {
+ return t.str[start:end]
+ }
+ return ""
+}
+
+var (
+ errPrivateUse = errors.New("cannot set a key on a private use tag")
+ errInvalidArguments = errors.New("invalid key or type")
+)
+
+// SetTypeForKey returns a new Tag with the key set to type, where key and type
+// are of the allowed values defined for the Unicode locale extension ('u') in
+// https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
+// An empty value removes an existing pair with the same key.
+func (t Tag) SetTypeForKey(key, value string) (Tag, error) {
+ if t.IsPrivateUse() {
+ return t, errPrivateUse
+ }
+ if len(key) != 2 {
+ return t, errInvalidArguments
+ }
+
+ // Remove the setting if value is "".
+ if value == "" {
+ start, end, _ := t.findTypeForKey(key)
+ if start != end {
+ // Remove key tag and leading '-'.
+ start -= 4
+
+ // Remove a possible empty extension.
+ if (end == len(t.str) || t.str[end+2] == '-') && t.str[start-2] == '-' {
+ start -= 2
+ }
+ if start == int(t.pVariant) && end == len(t.str) {
+ t.str = ""
+ t.pVariant, t.pExt = 0, 0
+ } else {
+ t.str = fmt.Sprintf("%s%s", t.str[:start], t.str[end:])
+ }
+ }
+ return t, nil
+ }
+
+ if len(value) < 3 || len(value) > 8 {
+ return t, errInvalidArguments
+ }
+
+ var (
+ buf [maxCoreSize + maxSimpleUExtensionSize]byte
+ uStart int // start of the -u extension.
+ )
+
+ // Generate the tag string if needed.
+ if t.str == "" {
+ uStart = t.genCoreBytes(buf[:])
+ buf[uStart] = '-'
+ uStart++
+ }
+
+ // Create new key-type pair and parse it to verify.
+ b := buf[uStart:]
+ copy(b, "u-")
+ copy(b[2:], key)
+ b[4] = '-'
+ b = b[:5+copy(b[5:], value)]
+ scan := makeScanner(b)
+ if parseExtensions(&scan); scan.err != nil {
+ return t, scan.err
+ }
+
+ // Assemble the replacement string.
+ if t.str == "" {
+ t.pVariant, t.pExt = byte(uStart-1), uint16(uStart-1)
+ t.str = string(buf[:uStart+len(b)])
+ } else {
+ s := t.str
+ start, end, hasExt := t.findTypeForKey(key)
+ if start == end {
+ if hasExt {
+ b = b[2:]
+ }
+ t.str = fmt.Sprintf("%s-%s%s", s[:start], b, s[end:])
+ } else {
+ t.str = fmt.Sprintf("%s%s%s", s[:start], value, s[end:])
+ }
+ }
+ return t, nil
+}
+
+// findKeyAndType returns the start and end position for the type corresponding
+// to key or the point at which to insert the key-value pair if the type
+// wasn't found. The hasExt return value reports whether an -u extension was present.
+// Note: the extensions are typically very small and are likely to contain
+// only one key-type pair.
+func (t Tag) findTypeForKey(key string) (start, end int, hasExt bool) {
+ p := int(t.pExt)
+ if len(key) != 2 || p == len(t.str) || p == 0 {
+ return p, p, false
+ }
+ s := t.str
+
+ // Find the correct extension.
+ for p++; s[p] != 'u'; p++ {
+ if s[p] > 'u' {
+ p--
+ return p, p, false
+ }
+ if p = nextExtension(s, p); p == len(s) {
+ return len(s), len(s), false
+ }
+ }
+ // Proceed to the hyphen following the extension name.
+ p++
+
+ // curKey is the key currently being processed.
+ curKey := ""
+
+ // Iterate over keys until we get the end of a section.
+ for {
+ // p points to the hyphen preceding the current token.
+ if p3 := p + 3; s[p3] == '-' {
+ // Found a key.
+ // Check whether we just processed the key that was requested.
+ if curKey == key {
+ return start, p, true
+ }
+ // Set to the next key and continue scanning type tokens.
+ curKey = s[p+1 : p3]
+ if curKey > key {
+ return p, p, true
+ }
+ // Start of the type token sequence.
+ start = p + 4
+ // A type is at least 3 characters long.
+ p += 7 // 4 + 3
+ } else {
+ // Attribute or type, which is at least 3 characters long.
+ p += 4
+ }
+ // p points past the third character of a type or attribute.
+ max := p + 5 // maximum length of token plus hyphen.
+ if len(s) < max {
+ max = len(s)
+ }
+ for ; p < max && s[p] != '-'; p++ {
+ }
+ // Bail if we have exhausted all tokens or if the next token starts
+ // a new extension.
+ if p == len(s) || s[p+2] == '-' {
+ if curKey == key {
+ return start, p, true
+ }
+ return p, p, true
+ }
+ }
+}
+
+// ParseBase parses a 2- or 3-letter ISO 639 code.
+// It returns a ValueError if s is a well-formed but unknown language identifier
+// or another error if another error occurred.
+func ParseBase(s string) (Language, error) {
+ if n := len(s); n < 2 || 3 < n {
+ return 0, ErrSyntax
+ }
+ var buf [3]byte
+ return getLangID(buf[:copy(buf[:], s)])
+}
+
+// ParseScript parses a 4-letter ISO 15924 code.
+// It returns a ValueError if s is a well-formed but unknown script identifier
+// or another error if another error occurred.
+func ParseScript(s string) (Script, error) {
+ if len(s) != 4 {
+ return 0, ErrSyntax
+ }
+ var buf [4]byte
+ return getScriptID(script, buf[:copy(buf[:], s)])
+}
+
+// EncodeM49 returns the Region for the given UN M.49 code.
+// It returns an error if r is not a valid code.
+func EncodeM49(r int) (Region, error) {
+ return getRegionM49(r)
+}
+
+// ParseRegion parses a 2- or 3-letter ISO 3166-1 or a UN M.49 code.
+// It returns a ValueError if s is a well-formed but unknown region identifier
+// or another error if another error occurred.
+func ParseRegion(s string) (Region, error) {
+ if n := len(s); n < 2 || 3 < n {
+ return 0, ErrSyntax
+ }
+ var buf [3]byte
+ return getRegionID(buf[:copy(buf[:], s)])
+}
+
+// IsCountry returns whether this region is a country or autonomous area. This
+// includes non-standard definitions from CLDR.
+func (r Region) IsCountry() bool {
+ if r == 0 || r.IsGroup() || r.IsPrivateUse() && r != _XK {
+ return false
+ }
+ return true
+}
+
+// IsGroup returns whether this region defines a collection of regions. This
+// includes non-standard definitions from CLDR.
+func (r Region) IsGroup() bool {
+ if r == 0 {
+ return false
+ }
+ return int(regionInclusion[r]) < len(regionContainment)
+}
+
+// Contains returns whether Region c is contained by Region r. It returns true
+// if c == r.
+func (r Region) Contains(c Region) bool {
+ if r == c {
+ return true
+ }
+ g := regionInclusion[r]
+ if g >= nRegionGroups {
+ return false
+ }
+ m := regionContainment[g]
+
+ d := regionInclusion[c]
+ b := regionInclusionBits[d]
+
+ // A contained country may belong to multiple disjoint groups. Matching any
+ // of these indicates containment. If the contained region is a group, it
+ // must strictly be a subset.
+ if d >= nRegionGroups {
+ return b&m != 0
+ }
+ return b&^m == 0
+}
+
+var errNoTLD = errors.New("language: region is not a valid ccTLD")
+
+// TLD returns the country code top-level domain (ccTLD). UK is returned for GB.
+// In all other cases it returns either the region itself or an error.
+//
+// This method may return an error for a region for which there exists a
+// canonical form with a ccTLD. To get that ccTLD canonicalize r first. The
+// region will already be canonicalized it was obtained from a Tag that was
+// obtained using any of the default methods.
+func (r Region) TLD() (Region, error) {
+ // See http://en.wikipedia.org/wiki/Country_code_top-level_domain for the
+ // difference between ISO 3166-1 and IANA ccTLD.
+ if r == _GB {
+ r = _UK
+ }
+ if (r.typ() & ccTLD) == 0 {
+ return 0, errNoTLD
+ }
+ return r, nil
+}
+
+// Canonicalize returns the region or a possible replacement if the region is
+// deprecated. It will not return a replacement for deprecated regions that
+// are split into multiple regions.
+func (r Region) Canonicalize() Region {
+ if cr := normRegion(r); cr != 0 {
+ return cr
+ }
+ return r
+}
+
+// Variant represents a registered variant of a language as defined by BCP 47.
+type Variant struct {
+ ID uint8
+ str string
+}
+
+// ParseVariant parses and returns a Variant. An error is returned if s is not
+// a valid variant.
+func ParseVariant(s string) (Variant, error) {
+ s = strings.ToLower(s)
+ if id, ok := variantIndex[s]; ok {
+ return Variant{id, s}, nil
+ }
+ return Variant{}, NewValueError([]byte(s))
+}
+
+// String returns the string representation of the variant.
+func (v Variant) String() string {
+ return v.str
+}
Code Review / barometer.git / blobdiff