xerror

var (
	// ErrDone done
	ErrDone                = errors.New("DONE")
	ErrBadRequest          = New(400, http.StatusText(400))
	ErrUnauthorized        = New(401, http.StatusText(401))
	ErrForbidden           = New(403, http.StatusText(403))
	ErrNotFound            = New(404, http.StatusText(404))
	ErrMethodNotAllowed    = New(405, http.StatusText(405))
	ErrTimeout             = New(408, http.StatusText(408))
	ErrConflict            = New(409, http.StatusText(409))
	ErrInternalServerError = New(500, http.StatusText(500))
	Debug                  bool
)

var (
	UnWrap = errors.Unwrap
	Is     = errors.Is
	As     = func(err error, target interface{}) bool {
		if target == nil {
			return false
		}

		val := reflect.ValueOf(target)
		typ := val.Type()

		if typ.Kind() != reflect.Ptr || val.IsNil() {
			return false
		}

		if e := typ.Elem(); e.Kind() != reflect.Interface && !typ.Implements(errorType) {
			return false
		}

		targetType := typ.Elem()
		for err != nil {
			if reflect.TypeOf(err).AssignableTo(targetType) {
				val.Elem().Set(reflect.ValueOf(err))
				return true
			}
			if x, ok := err.(interface{ As(interface{}) bool }); ok && x.As(target) {
				return true
			}
			err = UnWrap(err)
		}
		return false
	}
)