Private setter for var in primary constructor

Language Design
18

I’m not sure your annotation is the best approach. In terms of syntax it is clear that all this special stuff cannot really be done inside the primary constructor. For normal classes that isn’t really an issue, but for data classes this is. In both cases what you want to do is say that it is a property but it’s specification is deferred. Why not have something like:

data class Foo(deferred id:Int, val name: String) {
  deferred var id: Int
    private set
}

I’m not sure that repeating deferred on the definition as well is needed, but I think it is better as it signals that the value is set from the primary constructor as usual. For data classes the usual rules on data classes apply. Deferred properties obviously also have to have an underlying field.

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