// 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.
package language
import (
"bytes"
"fmt"
"sort"
"strconv"
"golang.org/x/text/internal/tag"
)
// findIndex tries to find the given tag in idx and returns a standardized error
// if it could not be found.
func findIndex(idx tag.Index, key []byte, form string) (index int, err error) {
if !tag.FixCase(form, key) {
return 0, errSyntax
}
i := idx.Index(key)
if i == -1 {
return 0, mkErrInvalid(key)
}
return i, nil
}
func searchUint(imap []uint16, key uint16) int {
return sort.Search(len(imap), func(i int) bool {
return imap[i] >= key
})
}
type langID uint16
// getLangID returns the langID of s if s is a canonical subtag
// or langUnknown if s is not a canonical subtag.
func getLangID(s []byte) (langID, error) {
if len(s) == 2 {
return getLangISO2(s)
}
return getLangISO3(s)
}
// mapLang returns the mapped langID of id according to mapping m.
func normLang(id langID) (langID, langAliasType) {
k := sort.Search(len(langAliasMap), func(i int) bool {
return langAliasMap[i].from >= uint16(id)
})
if k < len(langAliasMap) && langAliasMap[k].from == uint16(id) {
return langID(langAliasMap[k].to), langAliasTypes[k]
}
return id, langAliasTypeUnknown
}
// getLangISO2 returns the langID for the given 2-letter ISO language code
// or unknownLang if this does not exist.
func getLangISO2(s []byte) (langID, error) {
if !tag.FixCase("zz", s) {
return 0, errSyntax
}
if i := lang.Index(s); i != -1 && lang.Elem(i)[3] != 0 {
return langID(i), nil
}
return 0, mkErrInvalid(s)
}
const base = 'z' - 'a' + 1
func strToInt(s []byte) uint {
v := uint(0)
for i := 0; i < len(s); i++ {
v *= base
v += uint(s[i] - 'a')
}
return v
}
// converts the given integer to the original ASCII string passed to strToInt.
// len(s) must match the number of characters obtained.
func intToStr(v uint, s []byte) {
for i := len(s) - 1; i >= 0; i-- {
s[i] = byte(v%base) + 'a'
v /= base
}
}
// getLangISO3 returns the langID for the given 3-letter ISO language code
// or unknownLang if this does not exist.
func getLangISO3(s []byte) (langID, error) {
if tag.FixCase("und", s) {
// first try to match canonical 3-letter entries
for i := lang.Index(s[:2]); i != -1; i = lang.Next(s[:2], i) {
if e := lang.Elem(i); e[3] == 0 && e[2] == s[2] {
// We treat "und" as special and always translate it to "unspecified".
// Note that ZZ and Zzzz are private use and are not treated as
// unspecified by default.
id := langID(i)
if id == nonCanonicalUnd {
return 0, nil
}
return id, nil
}
}
if i := altLangISO3.Index(s); i != -1 {
return langID(altLangIndex[altLangISO3.Elem(i)[3]]), nil
}
n := strToInt(s)
if langNoIndex[n/8]&(1<<(n%8)) != 0 {
return langID(n) + langNoIndexOffset, nil
}
// Check for non-canonical uses of ISO3.
for i := lang.Index(s[:1]); i != -1; i = lang.Next(s[:1], i) {
if e := lang.Elem(i); e[2] == s[1] && e[3] == s[2] {
return langID(i), nil
}
}
return 0, mkErrInvalid(s)
}
return 0, errSyntax
}
// stringToBuf writes the string to b and returns the number of bytes
// written. cap(b) must be >= 3.
func (id langID) stringToBuf(b []byte) int {
if id >= langNoIndexOffset {
intToStr(uint(id)-langNoIndexOffset, b[:3])
return 3
} else if id == 0 {
return copy(b, "und")
}
l := lang[id<<2:]
if l[3] == 0 {
return copy(b, l[:3])
}
return copy(b, l[:2])
}
// String returns the BCP 47 representation of the langID.
// Use b as variable name, instead of id, to ensure the variable
// used is consistent with that of Base in which this type is embedded.
func (b langID) String() string {
if b == 0 {
return "und"
} else if b >= langNoIndexOffset {
b -= langNoIndexOffset
buf := [3]byte{}
intToStr(uint(b), buf[:])
return string(buf[:])
}
l := lang.Elem(int(b))
if l[3] == 0 {
return l[:3]
}
return l[:2]
}
// ISO3 returns the ISO 639-3 language code.
func (b langID) ISO3() string {
if b == 0 || b >= langNoIndexOffset {
return b.String()
}
l := lang.Elem(int(b))
if l[3] == 0 {
return l[:3]
} else if l[2] == 0 {
return altLangISO3.Elem(int(l[3]))[:3]
}
// This allocation will only happen for 3-letter ISO codes
// that are non-canonical BCP 47 language identifiers.
return l[0:1] + l[2:4]
}
// IsPrivateUse reports whether this language code is reserved for private use.
func (b langID) IsPrivateUse() bool {
return langPrivateStart <= b && b <= langPrivateEnd
}
type regionID uint16
// getRegionID returns the region id for s if s is a valid 2-letter region code
// or unknownRegion.
func getRegionID(s []byte) (regionID, error) {
if len(s) == 3 {
if isAlpha(s[0]) {
return getRegionISO3(s)
}
if i, err := strconv.ParseUint(string(s), 10, 10); err == nil {
return getRegionM49(int(i))
}
}
return getRegionISO2(s)
}
// getRegionISO2 returns the regionID for the given 2-letter ISO country code
// or unknownRegion if this does not exist.
func getRegionISO2(s []byte) (regionID, error) {
i, err := findIndex(regionISO, s, "ZZ")
if err != nil {
return 0, err
}
return regionID(i) + isoRegionOffset, nil
}
// getRegionISO3 returns the regionID for the given 3-letter ISO country code
// or unknownRegion if this does not exist.
func getRegionISO3(s []byte) (regionID, error) {
if tag.FixCase("ZZZ", s) {
for i := regionISO.Index(s[:1]); i != -1; i = regionISO.Next(s[:1], i) {
if e := regionISO.Elem(i); e[2] == s[1] && e[3] == s[2] {
return regionID(i) + isoRegionOffset, nil
}
}
for i := 0; i < len(altRegionISO3); i += 3 {
if tag.Compare(altRegionISO3[i:i+3], s) == 0 {
return regionID(altRegionIDs[i/3]), nil
}
}
return 0, mkErrInvalid(s)
}
return 0, errSyntax
}
func getRegionM49(n int) (regionID, error) {
if 0 < n && n <= 999 {
const (
searchBits = 7
regionBits = 9
regionMask = 1<<regionBits - 1
)
idx := n >> searchBits
buf := fromM49[m49Index[idx]:m49Index[idx+1]]
val := uint16(n) << regionBits // we rely on bits shifting out
i := sort.Search(len(buf), func(i int) bool {
return buf[i] >= val
})
if r := fromM49[int(m49Index[idx])+i]; r&^regionMask == val {
return regionID(r & regionMask), nil
}
}
var e ValueError
fmt.Fprint(bytes.NewBuffer([]byte(e.v[:])), n)
return 0, e
}
// normRegion returns a region if r is deprecated or 0 otherwise.
// TODO: consider supporting BYS (-> BLR), CSK (-> 200 or CZ), PHI (-> PHL) and AFI (-> DJ).
// TODO: consider mapping split up regions to new most populous one (like CLDR).
func normRegion(r regionID) regionID {
m := regionOldMap
k := sort.Search(len(m), func(i int) bool {
return m[i].from >= uint16(r)
})
if k < len(m) && m[k].from == uint16(r) {
return regionID(m[k].to)
}
return 0
}
const (
iso3166UserAssigned = 1 << iota
ccTLD
bcp47Region
)
func (r regionID) typ() byte {
return regionTypes[r]
}
// String returns the BCP 47 representation for the region.
// It returns "ZZ" for an unspecified region.
func (r regionID) String() string {
if r < isoRegionOffset {
if r == 0 {
return "ZZ"
}
return fmt.Sprintf("%03d", r.M49())
}
r -= isoRegionOffset
return regionISO.Elem(int(r))[:2]
}
// ISO3 returns the 3-letter ISO code of r.
// Note that not all regions have a 3-letter ISO code.
// In such cases this method returns "ZZZ".
func (r regionID) ISO3() string {
if r < isoRegionOffset {
return "ZZZ"
}
r -= isoRegionOffset
reg := regionISO.Elem(int(r))
switch reg[2] {
case 0:
return altRegionISO3[reg[3]:][:3]
case ' ':
return "ZZZ"
}
return reg[0:1] + reg[2:4]
}
// M49 returns the UN M.49 encoding of r, or 0 if this encoding
// is not defined for r.
func (r regionID) M49() int {
return int(m49[r])
}
// IsPrivateUse reports whether r has the ISO 3166 User-assigned status. This
// may include private-use tags that are assigned by CLDR and used in this
// implementation. So IsPrivateUse and IsCountry can be simultaneously true.
func (r regionID) IsPrivateUse() bool {
return r.typ()&iso3166UserAssigned != 0
}
type scriptID uint8
// getScriptID returns the script id for string s. It assumes that s
// is of the format [A-Z][a-z]{3}.
func getScriptID(idx tag.Index, s []byte) (scriptID, error) {
i, err := findIndex(idx, s, "Zzzz")
return scriptID(i), err
}
// String returns the script code in title case.
// It returns "Zzzz" for an unspecified script.
func (s scriptID) String() string {
if s == 0 {
return "Zzzz"
}
return script.Elem(int(s))
}
// IsPrivateUse reports whether this script code is reserved for private use.
func (s scriptID) IsPrivateUse() bool {
return _Qaaa <= s && s <= _Qabx
}
const (
maxAltTaglen = len("en-US-POSIX")
maxLen = maxAltTaglen
)
var (
// grandfatheredMap holds a mapping from legacy and grandfathered tags to
// their base language or index to more elaborate tag.
grandfatheredMap = map[[maxLen]byte]int16{
[maxLen]byte{'a', 'r', 't', '-', 'l', 'o', 'j', 'b', 'a', 'n'}: _jbo, // art-lojban
[maxLen]byte{'i', '-', 'a', 'm', 'i'}: _ami, // i-ami
[maxLen]byte{'i', '-', 'b', 'n', 'n'}: _bnn, // i-bnn
[maxLen]byte{'i', '-', 'h', 'a', 'k'}: _hak, // i-hak
[maxLen]byte{'i', '-', 'k', 'l', 'i', 'n', 'g', 'o', 'n'}: _tlh, // i-klingon
[maxLen]byte{'i', '-', 'l', 'u', 'x'}: _lb, // i-lux
[maxLen]byte{'i', '-', 'n', 'a', 'v', 'a', 'j', 'o'}: _nv, // i-navajo
[maxLen]byte{'i', '-', 'p', 'w', 'n'}: _pwn, // i-pwn
[maxLen]byte{'i', '-', 't', 'a', 'o'}: _tao, // i-tao
[maxLen]byte{'i', '-', 't', 'a', 'y'}: _tay, // i-tay
[maxLen]byte{'i', '-', 't', 's', 'u'}: _tsu, // i-tsu
[maxLen]byte{'n', 'o', '-', 'b', 'o', 'k'}: _nb, // no-bok
[maxLen]byte{'n', 'o', '-', 'n', 'y', 'n'}: _nn, // no-nyn
[maxLen]byte{'s', 'g', 'n', '-', 'b', 'e', '-', 'f', 'r'}: _sfb, // sgn-BE-FR
[maxLen]byte{'s', 'g', 'n', '-', 'b', 'e', '-', 'n', 'l'}: _vgt, // sgn-BE-NL
[maxLen]byte{'s', 'g', 'n', '-', 'c', 'h', '-', 'd', 'e'}: _sgg, // sgn-CH-DE
[maxLen]byte{'z', 'h', '-', 'g', 'u', 'o', 'y', 'u'}: _cmn, // zh-guoyu
[maxLen]byte{'z', 'h', '-', 'h', 'a', 'k', 'k', 'a'}: _hak, // zh-hakka
[maxLen]byte{'z', 'h', '-', 'm', 'i', 'n', '-', 'n', 'a', 'n'}: _nan, // zh-min-nan
[maxLen]byte{'z', 'h', '-', 'x', 'i', 'a', 'n', 'g'}: _hsn, // zh-xiang
// Grandfathered tags with no modern replacement will be converted as
// follows:
[maxLen]byte{'c', 'e', 'l', '-', 'g', 'a', 'u', 'l', 'i', 's', 'h'}: -1, // cel-gaulish
[maxLen]byte{'e', 'n', '-', 'g', 'b', '-', 'o', 'e', 'd'}: -2, // en-GB-oed
[maxLen]byte{'i', '-', 'd', 'e', 'f', 'a', 'u', 'l', 't'}: -3, // i-default
[maxLen]byte{'i', '-', 'e', 'n', 'o', 'c', 'h', 'i', 'a', 'n'}: -4, // i-enochian
[maxLen]byte{'i', '-', 'm', 'i', 'n', 'g', 'o'}: -5, // i-mingo
[maxLen]byte{'z', 'h', '-', 'm', 'i', 'n'}: -6, // zh-min
// CLDR-specific tag.
[maxLen]byte{'r', 'o', 'o', 't'}: 0, // root
[maxLen]byte{'e', 'n', '-', 'u', 's', '-', 'p', 'o', 's', 'i', 'x'}: -7, // en_US_POSIX"
}
altTagIndex = [...]uint8{0, 17, 31, 45, 61, 74, 86, 102}
altTags = "xtg-x-cel-gaulishen-GB-oxendicten-x-i-defaultund-x-i-enochiansee-x-i-mingonan-x-zh-minen-US-u-va-posix"
)
func grandfathered(s [maxAltTaglen]byte) (t Tag, ok bool) {
if v, ok := grandfatheredMap[s]; ok {
if v < 0 {
return Make(altTags[altTagIndex[-v-1]:altTagIndex[-v]]), true
}
t.lang = langID(v)
return t, true
}
return t, false
}
