// complications with instrumentation (coverage, etc).
func mapinitnoop()

// mapclone for implementing maps.Clone
//
//go:linkname mapclone maps.clone
func mapclone(m any) any {
	e := efaceOf(&m)
	e.data = unsafe.Pointer(mapclone2((*maptype)(unsafe.Pointer(e._type)), (*hmap)(e.data)))
	return m
}

}

func (m mapNil[a, b]) Apply(_ Nil[a]) any {
	return Nil[b]{}
}

type mapCons[a, b any] struct {
	f Function[a, b]
}

func (m mapCons[a, b]) Apply(xs Cons[a]) any {
	return Cons[b]{m.f.Apply(xs.Head), Map[a, b](m.f, xs.Tail)}
}

func Map[a, b any](f Function[a, b], xs List[a]) List[b] {
	return xs.Match(mapNil[a, b]{}, mapCons[a, b]{f}).(List[b])
}

func main() {

const wzURL = "https://raw.githubusercontent.com/unicode-org/cldr/main/common/supplemental/windowsZones.xml"

type MapZone struct {
	Other     string `xml:"other,attr"`
	Territory string `xml:"territory,attr"`
	Type      string `xml:"type,attr"`
}

type SupplementalData struct {
	Zones []MapZone `xml:"windowsZones>mapTimezones>mapZone"`
}

func readWindowsZones() ([]*zone, error) {
	r, err := http.Get(wzURL)
	if err != nil {

		Mapping:  mi.m,
		Address:  uint64(int64(src.Address) + mi.offset),
		Line:     make([]Line, len(src.Line)),
		IsFolded: src.IsFolded,
	}
	for i, ln := range src.Line {
		l.Line[i] = pm.mapLine(ln)
	}
	// Check memoization table. Must be done on the remapped location to
	// account for the remapped mapping ID.
	k := l.key()
	if ll, ok := pm.locations[k]; ok {
		pm.locationsByID[src.ID] = ll

		Mapping:  mi.m,
		Address:  uint64(int64(src.Address) + mi.offset),
		Line:     make([]Line, len(src.Line)),
		IsFolded: src.IsFolded,
	}
	for i, ln := range src.Line {
		l.Line[i] = pm.mapLine(ln)
	}
	// Check memoization table. Must be done on the remapped location to
	// account for the remapped mapping ID.
	k := l.key()
	if ll, ok := pm.locations[k]; ok {
		pm.locationsByID.set(src.ID, ll)