no plural rule registered for zh-Hant

[aitour]

hi,
I want i18n to translate between zh-Hans and zh-Hant. But the result was not expcted, and was always translated to zh-Hans. I follow the code and found code @bundle.go:98 returns an error.
return fmt.Errorf("no plural rule registered for %s", tag)

It seems no plural rule registered for zh-Hant. so the messages can't be registered.
Is this a bug?

[nicksnyder]

This should work. There is a plural rule for zh, which should match both zh-Hant and zh-Hans.

On bundle.go:96 either b.pluralRules doesn't contain the plural rule for zh for some reason, or there is a bug in the rules.go:10

If you could debug that would be helpful.

[aitour]

Thanks for your reply. I hacked the local code to work for my needs. But I'm don't know if this is a correct fix (the Parent()@golang.org/x/text/language/language.go:338 does not think of zh as parent of zh-Hant). Here's my [email protected]:10, which uses the base language to match:

func (r Rules) Rule(tag language.Tag) *Rule {
	for {
		if rule := r[tag]; rule != nil {
			return rule
		}
		tag = tag.Parent()
		if tag.IsRoot() {
			break
		}
	}

	base, _ := tag.Base()
	baseLang := language.MustParse(base.String())
	if rule := r[baseLang]; rule != nil {
		return rule
	}
	return nil
}

[nicksnyder]

Thanks for figuring this out. I am not sure if the behavior you are observing from golang.org/x/text/language is intentional or not so I filed golang/go#25603

Can you clarify what your use-case is? Your source translations are in zh-Hans and you are translating to zh-Hant?

[nicksnyder]

I pushed a fix to master. I found some bugs in your proposed workaround, so take a look.

[aitour]

Thanks for the fix and figuring the bug.
My use-case is translation in many languages include en, zh-Hans, zh-Hant and etc.
I simply use a map to find language.Tag

localesMap = map[string]language.Tag{
		"en":         language.English,
		"zh":         language.SimplifiedChinese,
		"zh-hans-cn": language.SimplifiedChinese,
		"zh-hans":    language.SimplifiedChinese,
		"zh-cn":      language.SimplifiedChinese,
		"zh-hant":    language.TraditionalChinese,
		"zh-tw":      language.TraditionalChinese,
		"ja":         language.Japanese,
		"fr":         language.French,
		"ru":         language.Russian,
		"es":         language.Spanish,
		"ko":         language.Korean,
		"ar":         language.Arabic,
	}

In the init proc I load the languages messages. But when langTag is language.TraditionalChinese, the AddMessage returns an error.

err = i18nBundle.AddMessages(langTag, localeMsgs...)
if err != nil {
	log.WithFields(log.Fields{"file": fi.Name(), "error": err}).Warn("add messages error")
}

When language is language.TraditionalChinese, the translation process returns SimplifiedChinese.

localizer := i18n.NewLocalizer(i18nBundle, language)