[paulcsmith]

TL;DR I totally agree. This can be done with Crystal and Lucky but I wanted to keep the example simple.

I totally agree with your sentiment and you have a lot of great points. This post was not meant to get too deep into things right off the bat, so it left off a lot of this stuff.

In this case the phone number always has a country code with +1 because we have a validation that ensures it won't make it into the database without it. We also only accept US country codes in the validation.

I get your point though that just having a `String` doesn't really guarantee that those validations took place, luckily, LuckyRecord has the idea of custom types that can define their own casting and validation behavior. So we could have done this:

``` field phone : UnitedStatesPhoneNumber? ```

And it would validate that the string param is a valid US number before saving. It would also do that for queries and you could add whatever other type specific methods you want to it. so you could do

``` def formatted_fax_number phone.try { |number| number.without_country_code } end ```

But like I said, I think this is fitting for a whole separate post, rather than an intro style post :D

[paulcsmith]

And for a Ruby/Elixir/dynamic lang programmer just catching `nil` is actually a pretty big win, even without the custom type.

I will go more into depth about leveraging the type system with Lucky for even better data modeling in one of the Lucky guides

[vidarh]

I just think it makes it a lot less interesting to cover that kind of intro use case, as it's not very compelling exactly because of reactions of "but that's not how I'd do it".

Even more so because the "try" syntax is exaggerated. This works fine:

    fax_number.try(:gsub,"+1", "")

And with a new enough version of Ruby, this works too:

    fax_number&.gsub("+1","")

You still need to remember to do it of course, but using the "old" syntax makes the problem seem exaggerated.