go1.18 execute task with retry option

retry.go

package util

type Result[T any] struct {
	Error error
	Value T
}

type WithRetry[T any] struct {
	limit  uint
	count  uint
	Result Result[T]
}

func NewWithRetry[T any](limit uint) *WithRetry[T] {
	return &WithRetry[T]{
		limit: limit,
		count: 0,
	}
}

func (r *WithRetry[T]) Do(fn func() Result[T]) *WithRetry[T] {
	for r.count < r.limit {
		r.count += 1
		r.Result = fn()
		if r.Result.Error == nil {
			return r
		}
	}
	return r
}

usage.go

if r := util.NewWithRetry[int](5).Do(func() util.Result[int] {
    var total int
    txError := db.Transaction(func(tx *gorm.DB) error {
        if err := tx.Raw("select 1+X").Row().Scan(&total); err != nil {
            return err
        }
        return nil
    }, &sql.TxOptions{
        Isolation: sql.LevelSerializable,
    })
    return util.Result[int]{
        Error: txError,
        Value: total,
    }
}); r.Result.Error != nil {
    panic(r.Result.Error)
}