func()

in internal/language/gen.go [715:847]

• 106 lines of code
• 26 McCabe index (conditional complexity)

func (b *builder) writeLanguage() {
	meta := b.supp.Metadata

	b.writeConst("nonCanonicalUnd", b.lang.index("und"))
	b.writeConsts(func(s string) int { return int(b.langIndex(s)) }, langConsts...)
	b.writeConst("langPrivateStart", b.langIndex("qaa"))
	b.writeConst("langPrivateEnd", b.langIndex("qtz"))

	// Get language codes that need to be mapped (overlong 3-letter codes,
	// deprecated 2-letter codes, legacy and grandfathered tags.)
	langAliasMap := stringSet{}
	aliasTypeMap := map[string]AliasType{}

	// altLangISO3 get the alternative ISO3 names that need to be mapped.
	altLangISO3 := stringSet{}
	// Add dummy start to avoid the use of index 0.
	altLangISO3.add("---")
	altLangISO3.updateLater("---", "aa")

	lang := b.lang.clone()
	for _, a := range meta.Alias.LanguageAlias {
		if a.Replacement == "" {
			a.Replacement = "und"
		}
		// TODO: support mapping to tags
		repl := strings.SplitN(a.Replacement, "_", 2)[0]
		if a.Reason == "overlong" {
			if len(a.Replacement) == 2 && len(a.Type) == 3 {
				lang.updateLater(a.Replacement, a.Type)
			}
		} else if len(a.Type) <= 3 {
			switch a.Reason {
			case "macrolanguage":
				aliasTypeMap[a.Type] = Macro
			case "deprecated":
				// handled elsewhere
				continue
			case "bibliographic", "legacy":
				if a.Type == "no" {
					continue
				}
				aliasTypeMap[a.Type] = Legacy
			default:
				log.Fatalf("new %s alias: %s", a.Reason, a.Type)
			}
			langAliasMap.add(a.Type)
			langAliasMap.updateLater(a.Type, repl)
		}
	}
	// Manually add the mapping of "nb" (Norwegian) to its macro language.
	// This can be removed if CLDR adopts this change.
	langAliasMap.add("nb")
	langAliasMap.updateLater("nb", "no")
	aliasTypeMap["nb"] = Macro

	for k, v := range b.registry {
		// Also add deprecated values for 3-letter ISO codes, which CLDR omits.
		if v.typ == "language" && v.deprecated != "" && v.preferred != "" {
			langAliasMap.add(k)
			langAliasMap.updateLater(k, v.preferred)
			aliasTypeMap[k] = Deprecated
		}
	}
	// Fix CLDR mappings.
	lang.updateLater("tl", "tgl")
	lang.updateLater("sh", "hbs")
	lang.updateLater("mo", "mol")
	lang.updateLater("no", "nor")
	lang.updateLater("tw", "twi")
	lang.updateLater("nb", "nob")
	lang.updateLater("ak", "aka")
	lang.updateLater("bh", "bih")

	// Ensure that each 2-letter code is matched with a 3-letter code.
	for _, v := range lang.s[1:] {
		s, ok := lang.update[v]
		if !ok {
			if s, ok = lang.update[langAliasMap.update[v]]; !ok {
				continue
			}
			lang.update[v] = s
		}
		if v[0] != s[0] {
			altLangISO3.add(s)
			altLangISO3.updateLater(s, v)
		}
	}

	// Complete canonicalized language tags.
	lang.freeze()
	for i, v := range lang.s {
		// We can avoid these manual entries by using the IANA registry directly.
		// Seems easier to update the list manually, as changes are rare.
		// The panic in this loop will trigger if we miss an entry.
		add := ""
		if s, ok := lang.update[v]; ok {
			if s[0] == v[0] {
				add = s[1:]
			} else {
				add = string([]byte{0, byte(altLangISO3.index(s))})
			}
		} else if len(v) == 3 {
			add = "\x00"
		} else {
			log.Panicf("no data for long form of %q", v)
		}
		lang.s[i] += add
	}
	b.writeConst("lang", tag.Index(lang.join()))

	b.writeConst("langNoIndexOffset", len(b.lang.s))

	// space of all valid 3-letter language identifiers.
	b.writeBitVector("langNoIndex", b.langNoIndex.slice())

	altLangIndex := []uint16{}
	for i, s := range altLangISO3.slice() {
		altLangISO3.s[i] += string([]byte{byte(len(altLangIndex))})
		if i > 0 {
			idx := b.lang.index(altLangISO3.update[s])
			altLangIndex = append(altLangIndex, uint16(idx))
		}
	}
	b.writeConst("altLangISO3", tag.Index(altLangISO3.join()))
	b.writeSlice("altLangIndex", altLangIndex)

	b.writeSortedMap("AliasMap", &langAliasMap, b.langIndex)
	types := make([]AliasType, len(langAliasMap.s))
	for i, s := range langAliasMap.s {
		types[i] = aliasTypeMap[s]
	}
	b.writeSlice("AliasTypes", types)
}