Use mattermost v5 module (#1192)

vendor/github.com/mattermost/go-i18n/i18n/language/pluralspec.go

@@ -0,0 +1,75 @@
+package language
+
+import "strings"
+
+// PluralSpec defines the CLDR plural rules for a language.
+// http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html
+// http://unicode.org/reports/tr35/tr35-numbers.html#Operands
+type PluralSpec struct {
+	Plurals    map[Plural]struct{}
+	PluralFunc func(*Operands) Plural
+}
+
+var pluralSpecs = make(map[string]*PluralSpec)
+
+func normalizePluralSpecID(id string) string {
+	id = strings.Replace(id, "_", "-", -1)
+	id = strings.ToLower(id)
+	return id
+}
+
+// RegisterPluralSpec registers a new plural spec for the language ids.
+func RegisterPluralSpec(ids []string, ps *PluralSpec) {
+	for _, id := range ids {
+		id = normalizePluralSpecID(id)
+		pluralSpecs[id] = ps
+	}
+}
+
+// Plural returns the plural category for number as defined by
+// the language's CLDR plural rules.
+func (ps *PluralSpec) Plural(number interface{}) (Plural, error) {
+	ops, err := newOperands(number)
+	if err != nil {
+		return Invalid, err
+	}
+	return ps.PluralFunc(ops), nil
+}
+
+// GetPluralSpec returns the PluralSpec that matches the longest prefix of tag.
+// It returns nil if no PluralSpec matches tag.
+func GetPluralSpec(tag string) *PluralSpec {
+	tag = NormalizeTag(tag)
+	subtag := tag
+	for {
+		if spec := pluralSpecs[subtag]; spec != nil {
+			return spec
+		}
+		end := strings.LastIndex(subtag, "-")
+		if end == -1 {
+			return nil
+		}
+		subtag = subtag[:end]
+	}
+}
+
+func newPluralSet(plurals ...Plural) map[Plural]struct{} {
+	set := make(map[Plural]struct{}, len(plurals))
+	for _, plural := range plurals {
+		set[plural] = struct{}{}
+	}
+	return set
+}
+
+func intInRange(i, from, to int64) bool {
+	return from <= i && i <= to
+}
+
+func intEqualsAny(i int64, any ...int64) bool {
+	for _, a := range any {
+		if i == a {
+			return true
+		}
+	}
+	return false
+}