locale.go

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//     http://www.apache.org/licenses/LICENSE-2.0
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

//go:generate go run generator.go

package lunes

import (
	"fmt"
)

// A Locale provides a collection of time layouts values in a specific language.
// It is used to provide a map between the time layout elements in foreign language to English.
type Locale interface {
	// Language represents a BCP 47 tag, specifying this locale language.
	Language() string

	// LongDayNames returns the long day names translations for the week days.
	// It must be sorted, starting from Sunday to Saturday, and contains all 7 elements,
	// even if one or more days are empty. If this locale does not support this format,
	// it should return an empty slice.
	LongDayNames() []string

	// ShortDayNames returns the short day names translations for the week days.
	// It must be sorted, starting from Sunday to Saturday, and contains all 7 elements,
	// even if one or more days are empty. If this locale does not support this format,
	// it should return an empty slice.
	ShortDayNames() []string

	// LongMonthNames returns the long day names translations for the months names.
	// It must be sorted, starting from January to December, and contains all 12 elements,
	// even if one or more months are empty. If this locale does not support this format,
	// it should return an empty slice.
	LongMonthNames() []string

	// ShortMonthNames returns the short day names translations for the months names.
	// It must be sorted, starting from January to December, and contains all 12 elements,
	// even if one or more months are empty. If this locale does not support this format,
	// it should return an empty slice.
	ShortMonthNames() []string

	// DayPeriods returns the periods of day translations for the AM and PM abbreviations.
	// It must be sorted, starting from AM to PM, and contains both elements, even if one
	// of them is empty. If this locale does not support this format, it should return an
	// empty slice.
	DayPeriods() []string
}

type genericLocale struct {
	lang  string
	table [5][]string
}

func (g *genericLocale) LongDayNames() []string {
	return g.table[longDayNamesField]
}

func (g *genericLocale) ShortDayNames() []string {
	return g.table[shortDayNamesField]
}

func (g *genericLocale) LongMonthNames() []string {
	return g.table[longMonthNamesField]
}

func (g *genericLocale) ShortMonthNames() []string {
	return g.table[shortMonthNamesField]
}

func (g *genericLocale) DayPeriods() []string {
	return g.table[dayPeriodsField]
}

func (g *genericLocale) Language() string {
	return g.lang
}

// ErrUnsupportedLocale indicates that a provided language.Tag is not supported by the
// default CLDR generic locales.
type ErrUnsupportedLocale struct {
	lang string
}

func (e *ErrUnsupportedLocale) Error() string {
	return fmt.Sprintf("locale %s not supported", e.lang)
}

// NewDefaultLocale creates a new generic locale for the given BCP 47 language tag, using
// the default CLDR gregorian calendars data of the specified language.
// If the language is unknown and no default data is found, it returns ErrUnsupportedLocale.
func NewDefaultLocale(lang string) (Locale, error) {
	table, ok := tables[lang]
	if !ok {
		return nil, &ErrUnsupportedLocale{lang}
	}

	locale := genericLocale{lang: lang, table: table}
	return &locale, nil
}