Transforming return type when using map #66
Description
Hi I have been looking to use this package in my solution however every time I have tried to so I feel like something is missing.
In our solution we want to use Options and Results every time we are uncertain of the return value.
I do use monads in python and node (typescript) and it's great there is a a lot that we can do with elegantly, and I do like MarshalJSON function that you have implemented.
My issue with mo is that when we need to map a type to another type, see example below.
this code is more like a pseudocode
type UserRequestForm struct {
Email string
FirstName string
LastName string
Address string // can be empty
Title string // can be empty
}
type User struct {
Id string // uuid/guid
Email string
Name string
FirstName string
LastName string
Address string // can be empty
Title string // can be empty
}
func (data UserRequestForm) TDO() User {
return User{
Id: uuidx.NewV4().String(),
Email: data.Email,
Name: fmt.Sprintf("%v %v", data.FirstName, data.LastName),
FirstName: data.FirstName,
LastName: data.LastName,
Address: data.Address,
Title: data.Title,
}
}
func UserRequestFormToDTO(value UserRequestForm) mo.Option[User] {
return mo.Some(value.TDO())
}Here I want to get a option of UserRequestForm and if it has a value I wan't to convert it to a TDO and push it to a DB.
So something looking like this:
func CreateUser(user mo.Option[UserRequestForm]) error {
return user.FlatMap(UserRequestFormToDTO).Match(
func(value User) {
db.CreateUser(value) // Value should be of type User
},
func() (error) {
return fmt.Errorf("Form data could to be converted to User database object ")
})
}I'm kind new to GO thereby I might be a bit ignorerat, so there might be that writing something like the code above is might not be a good idea.
However I know that there is good support generics and type inference in GO. So I don't see any issues with creating functions looking like this:
func Map[T any, R any](value T, callback func(T) R) R {
return callback(value)
}
func main() {
u := Map(data, UserRequestFormToDTO) // typeof u is User
}Here is my question, is there a reson why the Map and FlatMap function is hard code as generic. Or is just that you haven't implemented support for it yet, and in that case can I try to make PR?