+++ /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
-//go:generate go run gen_index.go
-
-package 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.
-type Tag struct {
- lang langID
- region regionID
- // TODO: we will soon run out of positions for script. Idea: instead of
- // storing lang, region, and script 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.
- script scriptID
- 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 {
- return Default.Make(s)
-}
-
-// Make is a convenience wrapper for c.Parse that omits the error.
-// In case of an error, a sensible default is returned.
-func (c CanonType) Make(s string) Tag {
- t, _ := c.Parse(s)
- return t
-}
-
-// Raw returns the raw base language, script and region, without making an
-// attempt to infer their values.
-func (t Tag) Raw() (b Base, s Script, r Region) {
- return Base{t.lang}, Script{t.script}, Region{t.region}
-}
-
-// equalTags compares language, script and region subtags only.
-func (t Tag) equalTags(a Tag) bool {
- return t.lang == a.lang && t.script == a.script && t.region == a.region
-}
-
-// 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)
-}
-
-// private reports whether the Tag consists solely of a private use tag.
-func (t Tag) private() bool {
- return t.str != "" && t.pVariant == 0
-}
-
-// CanonType can be used to enable or disable various types of canonicalization.
-type CanonType int
-
-const (
- // Replace deprecated base languages with their preferred replacements.
- DeprecatedBase CanonType = 1 << iota
- // Replace deprecated scripts with their preferred replacements.
- DeprecatedScript
- // Replace deprecated regions with their preferred replacements.
- DeprecatedRegion
- // Remove redundant scripts.
- SuppressScript
- // Normalize legacy encodings. This includes legacy languages defined in
- // CLDR as well as bibliographic codes defined in ISO-639.
- Legacy
- // Map the dominant language of a macro language group to the macro language
- // subtag. For example cmn -> zh.
- Macro
- // The CLDR flag should be used if full compatibility with CLDR is required.
- // There are a few cases where language.Tag may differ from CLDR. To follow all
- // of CLDR's suggestions, use All|CLDR.
- CLDR
-
- // Raw can be used to Compose or Parse without Canonicalization.
- Raw CanonType = 0
-
- // Replace all deprecated tags with their preferred replacements.
- Deprecated = DeprecatedBase | DeprecatedScript | DeprecatedRegion
-
- // All canonicalizations recommended by BCP 47.
- BCP47 = Deprecated | SuppressScript
-
- // All canonicalizations.
- All = BCP47 | Legacy | Macro
-
- // Default is the canonicalization used by Parse, Make and Compose. To
- // preserve as much information as possible, canonicalizations that remove
- // potentially valuable information are not included. The Matcher is
- // designed to recognize similar tags that would be the same if
- // they were canonicalized using All.
- Default = Deprecated | Legacy
-
- canonLang = DeprecatedBase | Legacy | Macro
-
- // TODO: LikelyScript, LikelyRegion: suppress similar to ICU.
-)
-
-// canonicalize returns the canonicalized equivalent of the tag and
-// whether there was any change.
-func (t Tag) canonicalize(c CanonType) (Tag, bool) {
- if c == Raw {
- return t, false
- }
- changed := false
- if c&SuppressScript != 0 {
- if t.lang < langNoIndexOffset && uint8(t.script) == suppressScript[t.lang] {
- t.script = 0
- changed = true
- }
- }
- if c&canonLang != 0 {
- for {
- if l, aliasType := normLang(t.lang); l != t.lang {
- switch aliasType {
- case langLegacy:
- if c&Legacy != 0 {
- if t.lang == _sh && t.script == 0 {
- t.script = _Latn
- }
- t.lang = l
- changed = true
- }
- case langMacro:
- if c&Macro != 0 {
- // We deviate here from CLDR. The mapping "nb" -> "no"
- // qualifies as a typical Macro language mapping. However,
- // for legacy reasons, CLDR maps "no", the macro language
- // code for Norwegian, to the dominant variant "nb". This
- // change is currently under consideration for CLDR as well.
- // See http://unicode.org/cldr/trac/ticket/2698 and also
- // http://unicode.org/cldr/trac/ticket/1790 for some of the
- // practical implications. TODO: this check could be removed
- // if CLDR adopts this change.
- if c&CLDR == 0 || t.lang != _nb {
- changed = true
- t.lang = l
- }
- }
- case langDeprecated:
- if c&DeprecatedBase != 0 {
- if t.lang == _mo && t.region == 0 {
- t.region = _MD
- }
- t.lang = l
- changed = true
- // Other canonicalization types may still apply.
- continue
- }
- }
- } else if c&Legacy != 0 && t.lang == _no && c&CLDR != 0 {
- t.lang = _nb
- changed = true
- }
- break
- }
- }
- if c&DeprecatedScript != 0 {
- if t.script == _Qaai {
- changed = true
- t.script = _Zinh
- }
- }
- if c&DeprecatedRegion != 0 {
- if r := normRegion(t.region); r != 0 {
- changed = true
- t.region = r
- }
- }
- return t, changed
-}
-
-// Canonicalize returns the canonicalized equivalent of the tag.
-func (c CanonType) Canonicalize(t Tag) (Tag, error) {
- t, changed := t.canonicalize(c)
- if changed {
- t.remakeString()
- }
- return t, nil
-}
-
-// Confidence indicates the level of certainty for a given return value.
-// For example, Serbian may be written in Cyrillic or Latin script.
-// The confidence level indicates whether a value was explicitly specified,
-// whether it is typically the only possible value, or whether there is
-// an ambiguity.
-type Confidence int
-
-const (
- No Confidence = iota // full confidence that there was no match
- Low // most likely value picked out of a set of alternatives
- High // value is generally assumed to be the correct match
- Exact // exact match or explicitly specified value
-)
-
-var confName = []string{"No", "Low", "High", "Exact"}
-
-func (c Confidence) String() string {
- return confName[c]
-}
-
-// 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.lang.stringToBuf(buf[:])
- if t.script != 0 {
- n += copy(buf[n:], "-")
- n += copy(buf[n:], t.script.String())
- }
- if t.region != 0 {
- n += copy(buf[n:], "-")
- n += copy(buf[n:], t.region.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.script == 0 && t.region == 0 {
- return t.lang.String()
- }
- buf := [maxCoreSize]byte{}
- return string(buf[:t.genCoreBytes(buf[:])])
-}
-
-// Base returns the base language of the language tag. If the base language is
-// unspecified, an attempt will be made to infer it from the context.
-// It uses a variant of CLDR's Add Likely Subtags algorithm. This is subject to change.
-func (t Tag) Base() (Base, Confidence) {
- if t.lang != 0 {
- return Base{t.lang}, Exact
- }
- c := High
- if t.script == 0 && !(Region{t.region}).IsCountry() {
- c = Low
- }
- if tag, err := addTags(t); err == nil && tag.lang != 0 {
- return Base{tag.lang}, c
- }
- return Base{0}, No
-}
-
-// Script infers the script for the language tag. If it was not explicitly given, it will infer
-// a most likely candidate.
-// If more than one script is commonly used for a language, the most likely one
-// is returned with a low confidence indication. For example, it returns (Cyrl, Low)
-// for Serbian.
-// If a script cannot be inferred (Zzzz, No) is returned. We do not use Zyyy (undetermined)
-// as one would suspect from the IANA registry for BCP 47. In a Unicode context Zyyy marks
-// common characters (like 1, 2, 3, '.', etc.) and is therefore more like multiple scripts.
-// See http://www.unicode.org/reports/tr24/#Values for more details. Zzzz is also used for
-// unknown value in CLDR. (Zzzz, Exact) is returned if Zzzz was explicitly specified.
-// Note that an inferred script is never guaranteed to be the correct one. Latin is
-// almost exclusively used for Afrikaans, but Arabic has been used for some texts
-// in the past. Also, the script that is commonly used may change over time.
-// It uses a variant of CLDR's Add Likely Subtags algorithm. This is subject to change.
-func (t Tag) Script() (Script, Confidence) {
- if t.script != 0 {
- return Script{t.script}, Exact
- }
- sc, c := scriptID(_Zzzz), No
- if t.lang < langNoIndexOffset {
- if scr := scriptID(suppressScript[t.lang]); scr != 0 {
- // Note: it is not always the case that a language with a suppress
- // script value is only written in one script (e.g. kk, ms, pa).
- if t.region == 0 {
- return Script{scriptID(scr)}, High
- }
- sc, c = scr, High
- }
- }
- if tag, err := addTags(t); err == nil {
- if tag.script != sc {
- sc, c = tag.script, Low
- }
- } else {
- t, _ = (Deprecated | Macro).Canonicalize(t)
- if tag, err := addTags(t); err == nil && tag.script != sc {
- sc, c = tag.script, Low
- }
- }
- return Script{sc}, c
-}
-
-// Region returns the region for the language tag. If it was not explicitly given, it will
-// infer a most likely candidate from the context.
-// It uses a variant of CLDR's Add Likely Subtags algorithm. This is subject to change.
-func (t Tag) Region() (Region, Confidence) {
- if t.region != 0 {
- return Region{t.region}, Exact
- }
- if t, err := addTags(t); err == nil {
- return Region{t.region}, Low // TODO: differentiate between high and low.
- }
- t, _ = (Deprecated | Macro).Canonicalize(t)
- if tag, err := addTags(t); err == nil {
- return Region{tag.region}, Low
- }
- return Region{_ZZ}, No // TODO: return world instead of undetermined?
-}
-
-// Variant returns the variants specified explicitly for this language tag.
-// or nil if no variant was specified.
-func (t Tag) Variants() []Variant {
- v := []Variant{}
- if int(t.pVariant) < int(t.pExt) {
- for x, str := "", t.str[t.pVariant:t.pExt]; str != ""; {
- x, str = nextToken(str)
- v = append(v, Variant{x})
- }
- }
- return v
-}
-
-// 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.
- t, _ = Raw.Compose(t.Raw())
- if t.region == 0 && t.script != 0 && t.lang != 0 {
- base, _ := addTags(Tag{lang: t.lang})
- if base.script == t.script {
- return Tag{lang: t.lang}
- }
- }
- return t
- }
- if t.lang != 0 {
- if t.region != 0 {
- maxScript := t.script
- if maxScript == 0 {
- max, _ := addTags(t)
- maxScript = max.script
- }
-
- for i := range parents {
- if langID(parents[i].lang) == t.lang && scriptID(parents[i].maxScript) == maxScript {
- for _, r := range parents[i].fromRegion {
- if regionID(r) == t.region {
- return Tag{
- lang: t.lang,
- script: scriptID(parents[i].script),
- region: regionID(parents[i].toRegion),
- }
- }
- }
- }
- }
-
- // Strip the script if it is the default one.
- base, _ := addTags(Tag{lang: t.lang})
- if base.script != maxScript {
- return Tag{lang: t.lang, script: maxScript}
- }
- return Tag{lang: t.lang}
- } else if t.script != 0 {
- // The parent for an base-script pair with a non-default script is
- // "und" instead of the base language.
- base, _ := addTags(Tag{lang: t.lang})
- if base.script != t.script {
- return und
- }
- return Tag{lang: t.lang}
- }
- }
- return und
-}
-
-// returns token t and the rest of the string.
-func nextToken(s string) (t, tail string) {
- p := strings.Index(s[1:], "-")
- if p == -1 {
- return s[1:], ""
- }
- p++
- return s[1:p], s[p:]
-}
-
-// Extension is a single BCP 47 extension.
-type Extension struct {
- s string
-}
-
-// String returns the string representation of the extension, including the
-// type tag.
-func (e Extension) String() string {
- return e.s
-}
-
-// ParseExtension parses s as an extension and returns it on success.
-func ParseExtension(s string) (e Extension, err error) {
- scan := makeScannerString(s)
- var end int
- if n := len(scan.token); n != 1 {
- return Extension{}, errSyntax
- }
- scan.toLower(0, len(scan.b))
- end = parseExtension(&scan)
- if end != len(s) {
- return Extension{}, errSyntax
- }
- return Extension{string(scan.b)}, nil
-}
-
-// Type returns the one-byte extension type of e. It returns 0 for the zero
-// exception.
-func (e Extension) Type() byte {
- if e.s == "" {
- return 0
- }
- return e.s[0]
-}
-
-// Tokens returns the list of tokens of e.
-func (e Extension) Tokens() []string {
- return strings.Split(e.s, "-")
-}
-
-// 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 Extension, 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 Extension{ext}, true
- }
- }
- return Extension{}, false
-}
-
-// Extensions returns all extensions of t.
-func (t Tag) Extensions() []Extension {
- e := []Extension{}
- for i := int(t.pExt); i < len(t.str)-1; {
- var ext string
- i, ext = getExtension(t.str, i)
- e = append(e, Extension{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
-// http://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
-// http://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.private() {
- 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
- }
- }
-}
-
-// CompactIndex returns an index, where 0 <= index < NumCompactTags, for tags
-// for which data exists in the text repository. The index will change over time
-// and should not be stored in persistent storage. Extensions, except for the
-// 'va' type of the 'u' extension, are ignored. It will return 0, false if no
-// compact tag exists, where 0 is the index for the root language (Und).
-func CompactIndex(t Tag) (index int, ok bool) {
- // TODO: perhaps give more frequent tags a lower index.
- // TODO: we could make the indexes stable. This will excluded some
- // possibilities for optimization, so don't do this quite yet.
- b, s, r := t.Raw()
- if len(t.str) > 0 {
- if strings.HasPrefix(t.str, "x-") {
- // We have no entries for user-defined tags.
- return 0, false
- }
- if uint16(t.pVariant) != t.pExt {
- // There are no tags with variants and an u-va type.
- if t.TypeForKey("va") != "" {
- return 0, false
- }
- t, _ = Raw.Compose(b, s, r, t.Variants())
- } else if _, ok := t.Extension('u'); ok {
- // Strip all but the 'va' entry.
- variant := t.TypeForKey("va")
- t, _ = Raw.Compose(b, s, r)
- t, _ = t.SetTypeForKey("va", variant)
- }
- if len(t.str) > 0 {
- // We have some variants.
- for i, s := range specialTags {
- if s == t {
- return i + 1, true
- }
- }
- return 0, false
- }
- }
- // No variants specified: just compare core components.
- // The key has the form lllssrrr, where l, s, and r are nibbles for
- // respectively the langID, scriptID, and regionID.
- key := uint32(b.langID) << (8 + 12)
- key |= uint32(s.scriptID) << 12
- key |= uint32(r.regionID)
- x, ok := coreTags[key]
- return int(x), ok
-}
-
-// Base is an ISO 639 language code, used for encoding the base language
-// of a language tag.
-type Base struct {
- langID
-}
-
-// 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) (Base, error) {
- if n := len(s); n < 2 || 3 < n {
- return Base{}, errSyntax
- }
- var buf [3]byte
- l, err := getLangID(buf[:copy(buf[:], s)])
- return Base{l}, err
-}
-
-// Script is a 4-letter ISO 15924 code for representing scripts.
-// It is idiomatically represented in title case.
-type Script struct {
- scriptID
-}
-
-// 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 Script{}, errSyntax
- }
- var buf [4]byte
- sc, err := getScriptID(script, buf[:copy(buf[:], s)])
- return Script{sc}, err
-}
-
-// Region is an ISO 3166-1 or UN M.49 code for representing countries and regions.
-type Region struct {
- regionID
-}
-
-// 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) {
- rid, err := getRegionM49(r)
- return Region{rid}, err
-}
-
-// 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 Region{}, errSyntax
- }
- var buf [3]byte
- r, err := getRegionID(buf[:copy(buf[:], s)])
- return Region{r}, err
-}
-
-// 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.regionID == 0 || r.IsGroup() || r.IsPrivateUse() && r.regionID != _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.regionID == 0 {
- return false
- }
- return int(regionInclusion[r.regionID]) < 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 {
- return r.regionID.contains(c.regionID)
-}
-
-func (r regionID) contains(c regionID) 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.regionID == _GB {
- r = Region{_UK}
- }
- if (r.typ() & ccTLD) == 0 {
- return Region{}, 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.regionID); cr != 0 {
- return Region{cr}
- }
- return r
-}
-
-// Variant represents a registered variant of a language as defined by BCP 47.
-type Variant struct {
- variant 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 _, ok := variantIndex[s]; ok {
- return Variant{s}, nil
- }
- return Variant{}, mkErrInvalid([]byte(s))
-}
-
-// String returns the string representation of the variant.
-func (v Variant) String() string {
- return v.variant
-}
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