func()

in internal/language/gen.go [889:1058]

• 148 lines of code
• 38 McCabe index (conditional complexity)

func (b *builder) writeRegion() {
	b.writeConsts(b.region.index, regionConsts...)

	isoOffset := b.region.index("AA")
	m49map := make([]int16, len(b.region.slice()))
	fromM49map := make(map[int16]int)
	altRegionISO3 := ""
	altRegionIDs := []uint16{}

	b.writeConst("isoRegionOffset", isoOffset)

	// 2-letter region lookup and mapping to numeric codes.
	regionISO := b.region.clone()
	regionISO.s = regionISO.s[isoOffset:]
	regionISO.sorted = false

	regionTypes := make([]byte, len(b.region.s))

	// Is the region valid BCP 47?
	for s, e := range b.registry {
		if len(s) == 2 && s == strings.ToUpper(s) {
			i := b.region.index(s)
			for _, d := range e.description {
				if strings.Contains(d, "Private use") {
					regionTypes[i] = iso3166UserAssigned
				}
			}
			regionTypes[i] |= bcp47Region
		}
	}

	// Is the region a valid ccTLD?
	r := gen.OpenIANAFile("domains/root/db")
	defer r.Close()

	buf, err := ioutil.ReadAll(r)
	failOnError(err)
	re := regexp.MustCompile(`"/domains/root/db/([a-z]{2}).html"`)
	for _, m := range re.FindAllSubmatch(buf, -1) {
		i := b.region.index(strings.ToUpper(string(m[1])))
		regionTypes[i] |= ccTLD
	}

	b.writeSlice("regionTypes", regionTypes)

	iso3Set := make(map[string]int)
	update := func(iso2, iso3 string) {
		i := regionISO.index(iso2)
		if j, ok := iso3Set[iso3]; !ok && iso3[0] == iso2[0] {
			regionISO.s[i] += iso3[1:]
			iso3Set[iso3] = -1
		} else {
			if ok && j >= 0 {
				regionISO.s[i] += string([]byte{0, byte(j)})
			} else {
				iso3Set[iso3] = len(altRegionISO3)
				regionISO.s[i] += string([]byte{0, byte(len(altRegionISO3))})
				altRegionISO3 += iso3
				altRegionIDs = append(altRegionIDs, uint16(isoOffset+i))
			}
		}
	}
	for _, tc := range b.supp.CodeMappings.TerritoryCodes {
		i := regionISO.index(tc.Type) + isoOffset
		if d := m49map[i]; d != 0 {
			log.Panicf("%s found as a duplicate UN.M49 code of %03d", tc.Numeric, d)
		}
		m49 := parseM49(tc.Numeric)
		m49map[i] = m49
		if r := fromM49map[m49]; r == 0 {
			fromM49map[m49] = i
		} else if r != i {
			dep := b.registry[regionISO.s[r-isoOffset]].deprecated
			if t := b.registry[tc.Type]; t != nil && dep != "" && (t.deprecated == "" || t.deprecated > dep) {
				fromM49map[m49] = i
			}
		}
	}
	for _, ta := range b.supp.Metadata.Alias.TerritoryAlias {
		if len(ta.Type) == 3 && ta.Type[0] <= '9' && len(ta.Replacement) == 2 {
			from := parseM49(ta.Type)
			if r := fromM49map[from]; r == 0 {
				fromM49map[from] = regionISO.index(ta.Replacement) + isoOffset
			}
		}
	}
	for _, tc := range b.supp.CodeMappings.TerritoryCodes {
		if len(tc.Alpha3) == 3 {
			update(tc.Type, tc.Alpha3)
		}
	}
	// This entries are not included in territoryCodes. Mostly 3-letter variants
	// of deleted codes and an entry for QU.
	for _, m := range []struct{ iso2, iso3 string }{
		{"CT", "CTE"},
		{"DY", "DHY"},
		{"HV", "HVO"},
		{"JT", "JTN"},
		{"MI", "MID"},
		{"NH", "NHB"},
		{"NQ", "ATN"},
		{"PC", "PCI"},
		{"PU", "PUS"},
		{"PZ", "PCZ"},
		{"RH", "RHO"},
		{"VD", "VDR"},
		{"WK", "WAK"},
		// These three-letter codes are used for others as well.
		{"FQ", "ATF"},
	} {
		update(m.iso2, m.iso3)
	}
	for i, s := range regionISO.s {
		if len(s) != 4 {
			regionISO.s[i] = s + "  "
		}
	}
	b.writeConst("regionISO", tag.Index(regionISO.join()))
	b.writeConst("altRegionISO3", altRegionISO3)
	b.writeSlice("altRegionIDs", altRegionIDs)

	// Create list of deprecated regions.
	// TODO: consider inserting SF -> FI. Not included by CLDR, but is the only
	// Transitionally-reserved mapping not included.
	regionOldMap := stringSet{}
	// Include regions in territoryAlias (not all are in the IANA registry!)
	for _, reg := range b.supp.Metadata.Alias.TerritoryAlias {
		if len(reg.Type) == 2 && reg.Reason == "deprecated" && len(reg.Replacement) == 2 {
			regionOldMap.add(reg.Type)
			regionOldMap.updateLater(reg.Type, reg.Replacement)
			i, _ := regionISO.find(reg.Type)
			j, _ := regionISO.find(reg.Replacement)
			if k := m49map[i+isoOffset]; k == 0 {
				m49map[i+isoOffset] = m49map[j+isoOffset]
			}
		}
	}
	b.writeSortedMap("regionOldMap", &regionOldMap, func(s string) uint16 {
		return uint16(b.region.index(s))
	})
	// 3-digit region lookup, groupings.
	for i := 1; i < isoOffset; i++ {
		m := parseM49(b.region.s[i])
		m49map[i] = m
		fromM49map[m] = i
	}
	b.writeSlice("m49", m49map)

	const (
		searchBits = 7
		regionBits = 9
	)
	if len(m49map) >= 1<<regionBits {
		log.Fatalf("Maximum number of regions exceeded: %d > %d", len(m49map), 1<<regionBits)
	}
	m49Index := [9]int16{}
	fromM49 := []uint16{}
	m49 := []int{}
	for k, _ := range fromM49map {
		m49 = append(m49, int(k))
	}
	sort.Ints(m49)
	for _, k := range m49[1:] {
		val := (k & (1<<searchBits - 1)) << regionBits
		fromM49 = append(fromM49, uint16(val|fromM49map[int16(k)]))
		m49Index[1:][k>>searchBits] = int16(len(fromM49))
	}
	b.writeSlice("m49Index", m49Index)
	b.writeSlice("fromM49", fromM49)
}