I wanna my `data class` to have non optional field...

# announcements

[Philip Dukhov]

I wanna my data class to have non optional field, but to be able to initialize it with a nil, which will be replaced by a default value. Something like this:

data class Text(val text: String) {
    constructor(textNullable: String?) : this(textNullable ?: "", nullable)
}

It works well on native, but on JVM I got following error:

Platform declaration clash: The following declarations have the same JVM signature (<init>(Ljava/lang/String;)V):
    constructor Text(text: String) defined in ...
    constructor Text(textNullable: String?) defined in ...

Any way I can bypass it? I think I could replace data class with class to remove the default constructor, but in this case I’ll lose other data class advantages, like copy(...)

[randomcat]

one option is fun Text(text: String?) = Text(text ?: "") as a separate function

[Nir]

What if you make the primary constructor private?

[Nir]

I would expect even with Jason's approach you'd still run into problems; the function call would be potentially ambiguous

[Nir]

Unless Kotlin gives preference to functions over constructors or something like that

[andylamax]

data class Text(val text: String="")

[Nir]

It looks like Kotlin indeed gives preference to the constructor, very spooky

[randomcat]

either the non-nullable overload wouldn't be a candidate (if the argument type is nullable) or it would be preferred (if the argument type is non-nullable)

[Nir]

Ah, that's a good point

[randomcat]

the preference for members doesn't come into play