Combinator for additional validation logic

[k-bx]

Hi, sorry if I've missed this somehow in existing API.

I have this part of form which is only displayed if the "trafficking" checkbox is checked, so I need to validate its fields only then. I couldn't figure out how to do this without exporting the Validator(..) constructors for matching. Currently I did it like this:

ifTraffickingEnabled : Validator error { subject | trafficking : Bool } -> Validator error { subject | trafficking : Bool }
ifTraffickingEnabled validator =
    V.Validator
        (\subject ->
            if subject.trafficking then
                let
                    (V.Validator f) =
                        validator
                in
                f subject

            else
                []
        )

modelValidator : Validator ( Field, String ) Model
modelValidator =
  V.all
    [ ...
    , ifTraffickingEnabled (V.ifNothing .totalBudget ( TotalBudget, "Can't be empty" ))
    ]

Did I miss something? Thanks!