Added multilanguage support

vendor/github.com/nicksnyder/go-i18n/v2/internal/plural/rule.go

@@ -0,0 +1,44 @@
+package plural
+
+import (
+	"golang.org/x/text/language"
+)
+
+// Rule 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 Rule struct {
+	PluralForms    map[Form]struct{}
+	PluralFormFunc func(*Operands) Form
+}
+
+func addPluralRules(rules Rules, ids []string, ps *Rule) {
+	for _, id := range ids {
+		if id == "root" {
+			continue
+		}
+		tag := language.MustParse(id)
+		rules[tag] = ps
+	}
+}
+
+func newPluralFormSet(pluralForms ...Form) map[Form]struct{} {
+	set := make(map[Form]struct{}, len(pluralForms))
+	for _, plural := range pluralForms {
+		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
+}