--- /dev/null
+// 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 cldr
+
+// This file implements the various inheritance constructs defined by LDML.
+// See http://www.unicode.org/reports/tr35/#Inheritance_and_Validity
+// for more details.
+
+import (
+ "fmt"
+ "log"
+ "reflect"
+ "regexp"
+ "sort"
+ "strings"
+)
+
+// fieldIter iterates over fields in a struct. It includes
+// fields of embedded structs.
+type fieldIter struct {
+ v reflect.Value
+ index, n []int
+}
+
+func iter(v reflect.Value) fieldIter {
+ if v.Kind() != reflect.Struct {
+ log.Panicf("value %v must be a struct", v)
+ }
+ i := fieldIter{
+ v: v,
+ index: []int{0},
+ n: []int{v.NumField()},
+ }
+ i.descent()
+ return i
+}
+
+func (i *fieldIter) descent() {
+ for f := i.field(); f.Anonymous && f.Type.NumField() > 0; f = i.field() {
+ i.index = append(i.index, 0)
+ i.n = append(i.n, f.Type.NumField())
+ }
+}
+
+func (i *fieldIter) done() bool {
+ return len(i.index) == 1 && i.index[0] >= i.n[0]
+}
+
+func skip(f reflect.StructField) bool {
+ return !f.Anonymous && (f.Name[0] < 'A' || f.Name[0] > 'Z')
+}
+
+func (i *fieldIter) next() {
+ for {
+ k := len(i.index) - 1
+ i.index[k]++
+ if i.index[k] < i.n[k] {
+ if !skip(i.field()) {
+ break
+ }
+ } else {
+ if k == 0 {
+ return
+ }
+ i.index = i.index[:k]
+ i.n = i.n[:k]
+ }
+ }
+ i.descent()
+}
+
+func (i *fieldIter) value() reflect.Value {
+ return i.v.FieldByIndex(i.index)
+}
+
+func (i *fieldIter) field() reflect.StructField {
+ return i.v.Type().FieldByIndex(i.index)
+}
+
+type visitor func(v reflect.Value) error
+
+var stopDescent = fmt.Errorf("do not recurse")
+
+func (f visitor) visit(x interface{}) error {
+ return f.visitRec(reflect.ValueOf(x))
+}
+
+// visit recursively calls f on all nodes in v.
+func (f visitor) visitRec(v reflect.Value) error {
+ if v.Kind() == reflect.Ptr {
+ if v.IsNil() {
+ return nil
+ }
+ return f.visitRec(v.Elem())
+ }
+ if err := f(v); err != nil {
+ if err == stopDescent {
+ return nil
+ }
+ return err
+ }
+ switch v.Kind() {
+ case reflect.Struct:
+ for i := iter(v); !i.done(); i.next() {
+ if err := f.visitRec(i.value()); err != nil {
+ return err
+ }
+ }
+ case reflect.Slice:
+ for i := 0; i < v.Len(); i++ {
+ if err := f.visitRec(v.Index(i)); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+// getPath is used for error reporting purposes only.
+func getPath(e Elem) string {
+ if e == nil {
+ return "<nil>"
+ }
+ if e.enclosing() == nil {
+ return e.GetCommon().name
+ }
+ if e.GetCommon().Type == "" {
+ return fmt.Sprintf("%s.%s", getPath(e.enclosing()), e.GetCommon().name)
+ }
+ return fmt.Sprintf("%s.%s[type=%s]", getPath(e.enclosing()), e.GetCommon().name, e.GetCommon().Type)
+}
+
+// xmlName returns the xml name of the element or attribute
+func xmlName(f reflect.StructField) (name string, attr bool) {
+ tags := strings.Split(f.Tag.Get("xml"), ",")
+ for _, s := range tags {
+ attr = attr || s == "attr"
+ }
+ return tags[0], attr
+}
+
+func findField(v reflect.Value, key string) (reflect.Value, error) {
+ v = reflect.Indirect(v)
+ for i := iter(v); !i.done(); i.next() {
+ if n, _ := xmlName(i.field()); n == key {
+ return i.value(), nil
+ }
+ }
+ return reflect.Value{}, fmt.Errorf("cldr: no field %q in element %#v", key, v.Interface())
+}
+
+var xpathPart = regexp.MustCompile(`(\pL+)(?:\[@(\pL+)='([\w-]+)'\])?`)
+
+func walkXPath(e Elem, path string) (res Elem, err error) {
+ for _, c := range strings.Split(path, "/") {
+ if c == ".." {
+ if e = e.enclosing(); e == nil {
+ panic("path ..")
+ return nil, fmt.Errorf(`cldr: ".." moves past root in path %q`, path)
+ }
+ continue
+ } else if c == "" {
+ continue
+ }
+ m := xpathPart.FindStringSubmatch(c)
+ if len(m) == 0 || len(m[0]) != len(c) {
+ return nil, fmt.Errorf("cldr: syntax error in path component %q", c)
+ }
+ v, err := findField(reflect.ValueOf(e), m[1])
+ if err != nil {
+ return nil, err
+ }
+ switch v.Kind() {
+ case reflect.Slice:
+ i := 0
+ if m[2] != "" || v.Len() > 1 {
+ if m[2] == "" {
+ m[2] = "type"
+ if m[3] = e.GetCommon().Default(); m[3] == "" {
+ return nil, fmt.Errorf("cldr: type selector or default value needed for element %s", m[1])
+ }
+ }
+ for ; i < v.Len(); i++ {
+ vi := v.Index(i)
+ key, err := findField(vi.Elem(), m[2])
+ if err != nil {
+ return nil, err
+ }
+ key = reflect.Indirect(key)
+ if key.Kind() == reflect.String && key.String() == m[3] {
+ break
+ }
+ }
+ }
+ if i == v.Len() || v.Index(i).IsNil() {
+ return nil, fmt.Errorf("no %s found with %s==%s", m[1], m[2], m[3])
+ }
+ e = v.Index(i).Interface().(Elem)
+ case reflect.Ptr:
+ if v.IsNil() {
+ return nil, fmt.Errorf("cldr: element %q not found within element %q", m[1], e.GetCommon().name)
+ }
+ var ok bool
+ if e, ok = v.Interface().(Elem); !ok {
+ return nil, fmt.Errorf("cldr: %q is not an XML element", m[1])
+ } else if m[2] != "" || m[3] != "" {
+ return nil, fmt.Errorf("cldr: no type selector allowed for element %s", m[1])
+ }
+ default:
+ return nil, fmt.Errorf("cldr: %q is not an XML element", m[1])
+ }
+ }
+ return e, nil
+}
+
+const absPrefix = "//ldml/"
+
+func (cldr *CLDR) resolveAlias(e Elem, src, path string) (res Elem, err error) {
+ if src != "locale" {
+ if !strings.HasPrefix(path, absPrefix) {
+ return nil, fmt.Errorf("cldr: expected absolute path, found %q", path)
+ }
+ path = path[len(absPrefix):]
+ if e, err = cldr.resolve(src); err != nil {
+ return nil, err
+ }
+ }
+ return walkXPath(e, path)
+}
+
+func (cldr *CLDR) resolveAndMergeAlias(e Elem) error {
+ alias := e.GetCommon().Alias
+ if alias == nil {
+ return nil
+ }
+ a, err := cldr.resolveAlias(e, alias.Source, alias.Path)
+ if err != nil {
+ return fmt.Errorf("%v: error evaluating path %q: %v", getPath(e), alias.Path, err)
+ }
+ // Ensure alias node was already evaluated. TODO: avoid double evaluation.
+ err = cldr.resolveAndMergeAlias(a)
+ v := reflect.ValueOf(e).Elem()
+ for i := iter(reflect.ValueOf(a).Elem()); !i.done(); i.next() {
+ if vv := i.value(); vv.Kind() != reflect.Ptr || !vv.IsNil() {
+ if _, attr := xmlName(i.field()); !attr {
+ v.FieldByIndex(i.index).Set(vv)
+ }
+ }
+ }
+ return err
+}
+
+func (cldr *CLDR) aliasResolver() visitor {
+ return func(v reflect.Value) (err error) {
+ if e, ok := v.Addr().Interface().(Elem); ok {
+ err = cldr.resolveAndMergeAlias(e)
+ if err == nil && blocking[e.GetCommon().name] {
+ return stopDescent
+ }
+ }
+ return err
+ }
+}
+
+// elements within blocking elements do not inherit.
+// Taken from CLDR's supplementalMetaData.xml.
+var blocking = map[string]bool{
+ "identity": true,
+ "supplementalData": true,
+ "cldrTest": true,
+ "collation": true,
+ "transform": true,
+}
+
+// Distinguishing attributes affect inheritance; two elements with different
+// distinguishing attributes are treated as different for purposes of inheritance,
+// except when such attributes occur in the indicated elements.
+// Taken from CLDR's supplementalMetaData.xml.
+var distinguishing = map[string][]string{
+ "key": nil,
+ "request_id": nil,
+ "id": nil,
+ "registry": nil,
+ "alt": nil,
+ "iso4217": nil,
+ "iso3166": nil,
+ "mzone": nil,
+ "from": nil,
+ "to": nil,
+ "type": []string{
+ "abbreviationFallback",
+ "default",
+ "mapping",
+ "measurementSystem",
+ "preferenceOrdering",
+ },
+ "numberSystem": nil,
+}
+
+func in(set []string, s string) bool {
+ for _, v := range set {
+ if v == s {
+ return true
+ }
+ }
+ return false
+}
+
+// attrKey computes a key based on the distinguishable attributes of
+// an element and it's values.
+func attrKey(v reflect.Value, exclude ...string) string {
+ parts := []string{}
+ ename := v.Interface().(Elem).GetCommon().name
+ v = v.Elem()
+ for i := iter(v); !i.done(); i.next() {
+ if name, attr := xmlName(i.field()); attr {
+ if except, ok := distinguishing[name]; ok && !in(exclude, name) && !in(except, ename) {
+ v := i.value()
+ if v.Kind() == reflect.Ptr {
+ v = v.Elem()
+ }
+ if v.IsValid() {
+ parts = append(parts, fmt.Sprintf("%s=%s", name, v.String()))
+ }
+ }
+ }
+ }
+ sort.Strings(parts)
+ return strings.Join(parts, ";")
+}
+
+// Key returns a key for e derived from all distinguishing attributes
+// except those specified by exclude.
+func Key(e Elem, exclude ...string) string {
+ return attrKey(reflect.ValueOf(e), exclude...)
+}
+
+// linkEnclosing sets the enclosing element as well as the name
+// for all sub-elements of child, recursively.
+func linkEnclosing(parent, child Elem) {
+ child.setEnclosing(parent)
+ v := reflect.ValueOf(child).Elem()
+ for i := iter(v); !i.done(); i.next() {
+ vf := i.value()
+ if vf.Kind() == reflect.Slice {
+ for j := 0; j < vf.Len(); j++ {
+ linkEnclosing(child, vf.Index(j).Interface().(Elem))
+ }
+ } else if vf.Kind() == reflect.Ptr && !vf.IsNil() && vf.Elem().Kind() == reflect.Struct {
+ linkEnclosing(child, vf.Interface().(Elem))
+ }
+ }
+}
+
+func setNames(e Elem, name string) {
+ e.setName(name)
+ v := reflect.ValueOf(e).Elem()
+ for i := iter(v); !i.done(); i.next() {
+ vf := i.value()
+ name, _ = xmlName(i.field())
+ if vf.Kind() == reflect.Slice {
+ for j := 0; j < vf.Len(); j++ {
+ setNames(vf.Index(j).Interface().(Elem), name)
+ }
+ } else if vf.Kind() == reflect.Ptr && !vf.IsNil() && vf.Elem().Kind() == reflect.Struct {
+ setNames(vf.Interface().(Elem), name)
+ }
+ }
+}
+
+// deepCopy copies elements of v recursively. All elements of v that may
+// be modified by inheritance are explicitly copied.
+func deepCopy(v reflect.Value) reflect.Value {
+ switch v.Kind() {
+ case reflect.Ptr:
+ if v.IsNil() || v.Elem().Kind() != reflect.Struct {
+ return v
+ }
+ nv := reflect.New(v.Elem().Type())
+ nv.Elem().Set(v.Elem())
+ deepCopyRec(nv.Elem(), v.Elem())
+ return nv
+ case reflect.Slice:
+ nv := reflect.MakeSlice(v.Type(), v.Len(), v.Len())
+ for i := 0; i < v.Len(); i++ {
+ deepCopyRec(nv.Index(i), v.Index(i))
+ }
+ return nv
+ }
+ panic("deepCopy: must be called with pointer or slice")
+}
+
+// deepCopyRec is only called by deepCopy.
+func deepCopyRec(nv, v reflect.Value) {
+ if v.Kind() == reflect.Struct {
+ t := v.Type()
+ for i := 0; i < v.NumField(); i++ {
+ if name, attr := xmlName(t.Field(i)); name != "" && !attr {
+ deepCopyRec(nv.Field(i), v.Field(i))
+ }
+ }
+ } else {
+ nv.Set(deepCopy(v))
+ }
+}
+
+// newNode is used to insert a missing node during inheritance.
+func (cldr *CLDR) newNode(v, enc reflect.Value) reflect.Value {
+ n := reflect.New(v.Type())
+ for i := iter(v); !i.done(); i.next() {
+ if name, attr := xmlName(i.field()); name == "" || attr {
+ n.Elem().FieldByIndex(i.index).Set(i.value())
+ }
+ }
+ n.Interface().(Elem).GetCommon().setEnclosing(enc.Addr().Interface().(Elem))
+ return n
+}
+
+// v, parent must be pointers to struct
+func (cldr *CLDR) inheritFields(v, parent reflect.Value) (res reflect.Value, err error) {
+ t := v.Type()
+ nv := reflect.New(t)
+ nv.Elem().Set(v)
+ for i := iter(v); !i.done(); i.next() {
+ vf := i.value()
+ f := i.field()
+ name, attr := xmlName(f)
+ if name == "" || attr {
+ continue
+ }
+ pf := parent.FieldByIndex(i.index)
+ if blocking[name] {
+ if vf.IsNil() {
+ vf = pf
+ }
+ nv.Elem().FieldByIndex(i.index).Set(deepCopy(vf))
+ continue
+ }
+ switch f.Type.Kind() {
+ case reflect.Ptr:
+ if f.Type.Elem().Kind() == reflect.Struct {
+ if !vf.IsNil() {
+ if vf, err = cldr.inheritStructPtr(vf, pf); err != nil {
+ return reflect.Value{}, err
+ }
+ vf.Interface().(Elem).setEnclosing(nv.Interface().(Elem))
+ nv.Elem().FieldByIndex(i.index).Set(vf)
+ } else if !pf.IsNil() {
+ n := cldr.newNode(pf.Elem(), v)
+ if vf, err = cldr.inheritStructPtr(n, pf); err != nil {
+ return reflect.Value{}, err
+ }
+ vf.Interface().(Elem).setEnclosing(nv.Interface().(Elem))
+ nv.Elem().FieldByIndex(i.index).Set(vf)
+ }
+ }
+ case reflect.Slice:
+ vf, err := cldr.inheritSlice(nv.Elem(), vf, pf)
+ if err != nil {
+ return reflect.Zero(t), err
+ }
+ nv.Elem().FieldByIndex(i.index).Set(vf)
+ }
+ }
+ return nv, nil
+}
+
+func root(e Elem) *LDML {
+ for ; e.enclosing() != nil; e = e.enclosing() {
+ }
+ return e.(*LDML)
+}
+
+// inheritStructPtr first merges possible aliases in with v and then inherits
+// any underspecified elements from parent.
+func (cldr *CLDR) inheritStructPtr(v, parent reflect.Value) (r reflect.Value, err error) {
+ if !v.IsNil() {
+ e := v.Interface().(Elem).GetCommon()
+ alias := e.Alias
+ if alias == nil && !parent.IsNil() {
+ alias = parent.Interface().(Elem).GetCommon().Alias
+ }
+ if alias != nil {
+ a, err := cldr.resolveAlias(v.Interface().(Elem), alias.Source, alias.Path)
+ if a != nil {
+ if v, err = cldr.inheritFields(v.Elem(), reflect.ValueOf(a).Elem()); err != nil {
+ return reflect.Value{}, err
+ }
+ }
+ }
+ if !parent.IsNil() {
+ return cldr.inheritFields(v.Elem(), parent.Elem())
+ }
+ } else if parent.IsNil() {
+ panic("should not reach here")
+ }
+ return v, nil
+}
+
+// Must be slice of struct pointers.
+func (cldr *CLDR) inheritSlice(enc, v, parent reflect.Value) (res reflect.Value, err error) {
+ t := v.Type()
+ index := make(map[string]reflect.Value)
+ if !v.IsNil() {
+ for i := 0; i < v.Len(); i++ {
+ vi := v.Index(i)
+ key := attrKey(vi)
+ index[key] = vi
+ }
+ }
+ if !parent.IsNil() {
+ for i := 0; i < parent.Len(); i++ {
+ vi := parent.Index(i)
+ key := attrKey(vi)
+ if w, ok := index[key]; ok {
+ index[key], err = cldr.inheritStructPtr(w, vi)
+ } else {
+ n := cldr.newNode(vi.Elem(), enc)
+ index[key], err = cldr.inheritStructPtr(n, vi)
+ }
+ index[key].Interface().(Elem).setEnclosing(enc.Addr().Interface().(Elem))
+ if err != nil {
+ return v, err
+ }
+ }
+ }
+ keys := make([]string, 0, len(index))
+ for k, _ := range index {
+ keys = append(keys, k)
+ }
+ sort.Strings(keys)
+ sl := reflect.MakeSlice(t, len(index), len(index))
+ for i, k := range keys {
+ sl.Index(i).Set(index[k])
+ }
+ return sl, nil
+}
+
+func parentLocale(loc string) string {
+ parts := strings.Split(loc, "_")
+ if len(parts) == 1 {
+ return "root"
+ }
+ parts = parts[:len(parts)-1]
+ key := strings.Join(parts, "_")
+ return key
+}
+
+func (cldr *CLDR) resolve(loc string) (res *LDML, err error) {
+ if r := cldr.resolved[loc]; r != nil {
+ return r, nil
+ }
+ x := cldr.RawLDML(loc)
+ if x == nil {
+ return nil, fmt.Errorf("cldr: unknown locale %q", loc)
+ }
+ var v reflect.Value
+ if loc == "root" {
+ x = deepCopy(reflect.ValueOf(x)).Interface().(*LDML)
+ linkEnclosing(nil, x)
+ err = cldr.aliasResolver().visit(x)
+ } else {
+ key := parentLocale(loc)
+ var parent *LDML
+ for ; cldr.locale[key] == nil; key = parentLocale(key) {
+ }
+ if parent, err = cldr.resolve(key); err != nil {
+ return nil, err
+ }
+ v, err = cldr.inheritFields(reflect.ValueOf(x).Elem(), reflect.ValueOf(parent).Elem())
+ x = v.Interface().(*LDML)
+ linkEnclosing(nil, x)
+ }
+ if err != nil {
+ return nil, err
+ }
+ cldr.resolved[loc] = x
+ return x, err
+}
+
+// finalize finalizes the initialization of the raw LDML structs. It also
+// removed unwanted fields, as specified by filter, so that they will not
+// be unnecessarily evaluated.
+func (cldr *CLDR) finalize(filter []string) {
+ for _, x := range cldr.locale {
+ if filter != nil {
+ v := reflect.ValueOf(x).Elem()
+ t := v.Type()
+ for i := 0; i < v.NumField(); i++ {
+ f := t.Field(i)
+ name, _ := xmlName(f)
+ if name != "" && name != "identity" && !in(filter, name) {
+ v.Field(i).Set(reflect.Zero(f.Type))
+ }
+ }
+ }
+ linkEnclosing(nil, x) // for resolving aliases and paths
+ setNames(x, "ldml")
+ }
+}
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