gtsocial-umbx

lookup.go (12387B)

---

 // 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, NewValueError(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 Language 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) (Language, error) {
 	if len(s) == 2 {
 		return getLangISO2(s)
 	}
 	return getLangISO3(s)
 }
 
 // TODO language normalization as well as the AliasMaps could be moved to the
 // higher level package, but it is a bit tricky to separate the generation.
 
 func (id Language) Canonicalize() (Language, AliasType) {
 	return normLang(id)
 }
 
 // normLang returns the mapped langID of id according to mapping m.
 func normLang(id Language) (Language, AliasType) {
 	k := sort.Search(len(AliasMap), func(i int) bool {
 		return AliasMap[i].From >= uint16(id)
 	})
 	if k < len(AliasMap) && AliasMap[k].From == uint16(id) {
 		return Language(AliasMap[k].To), AliasTypes[k]
 	}
 	return id, AliasTypeUnknown
 }
 
 // getLangISO2 returns the langID for the given 2-letter ISO language code
 // or unknownLang if this does not exist.
 func getLangISO2(s []byte) (Language, error) {
 	if !tag.FixCase("zz", s) {
 		return 0, ErrSyntax
 	}
 	if i := lang.Index(s); i != -1 && lang.Elem(i)[3] != 0 {
 		return Language(i), nil
 	}
 	return 0, NewValueError(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) (Language, 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 := Language(i)
 				if id == nonCanonicalUnd {
 					return 0, nil
 				}
 				return id, nil
 			}
 		}
 		if i := altLangISO3.Index(s); i != -1 {
 			return Language(altLangIndex[altLangISO3.Elem(i)[3]]), nil
 		}
 		n := strToInt(s)
 		if langNoIndex[n/8]&(1<<(n%8)) != 0 {
 			return Language(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 Language(i), nil
 			}
 		}
 		return 0, NewValueError(s)
 	}
 	return 0, ErrSyntax
 }
 
 // StringToBuf writes the string to b and returns the number of bytes
 // written.  cap(b) must be >= 3.
 func (id Language) 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 Language) 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 Language) 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 Language) IsPrivateUse() bool {
 	return langPrivateStart <= b && b <= langPrivateEnd
 }
 
 // SuppressScript returns the script marked as SuppressScript in the IANA
 // language tag repository, or 0 if there is no such script.
 func (b Language) SuppressScript() Script {
 	if b < langNoIndexOffset {
 		return Script(suppressScript[b])
 	}
 	return 0
 }
 
 type Region uint16
 
 // getRegionID returns the region id for s if s is a valid 2-letter region code
 // or unknownRegion.
 func getRegionID(s []byte) (Region, 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) (Region, error) {
 	i, err := findIndex(regionISO, s, "ZZ")
 	if err != nil {
 		return 0, err
 	}
 	return Region(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) (Region, 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 Region(i) + isoRegionOffset, nil
 			}
 		}
 		for i := 0; i < len(altRegionISO3); i += 3 {
 			if tag.Compare(altRegionISO3[i:i+3], s) == 0 {
 				return Region(altRegionIDs[i/3]), nil
 			}
 		}
 		return 0, NewValueError(s)
 	}
 	return 0, ErrSyntax
 }
 
 func getRegionM49(n int) (Region, 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 Region(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 Region) Region {
 	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 Region(m[k].To)
 	}
 	return 0
 }
 
 const (
 	iso3166UserAssigned = 1 << iota
 	ccTLD
 	bcp47Region
 )
 
 func (r Region) typ() byte {
 	return regionTypes[r]
 }
 
 // String returns the BCP 47 representation for the region.
 // It returns "ZZ" for an unspecified region.
 func (r Region) 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 Region) 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 Region) 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 Region) IsPrivateUse() bool {
 	return r.typ()&iso3166UserAssigned != 0
 }
 
 type Script uint16
 
 // 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) (Script, error) {
 	i, err := findIndex(idx, s, "Zzzz")
 	return Script(i), err
 }
 
 // String returns the script code in title case.
 // It returns "Zzzz" for an unspecified script.
 func (s Script) 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 Script) 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.LangID = Language(v)
 		return t, true
 	}
 	return t, false
 }