I don’t think that’s a legal comparison, doubt there’s a `compareTo(Any?)` defined

# getting-started

[Shawn]

I don’t think that’s a legal comparison, doubt there’s a compareTo(Any?) defined

[Hullaballoonatic]

So how might I go about defining that myself? Is it just a big chain of when for every type?

[karelpeeters]

I would not recommend doing this.

[karelpeeters]

If you just want to eg. sort a list and have null in from use sortWith{ }.

[Hullaballoonatic]

well, here's what I'm attempting to do.. I believe it should be clear from the code

interface Consumable<Q: Quantity<Q>> {
    var quantityLostOnConsumption: ComparableQuantity<Q>
    var consumableQuantity: ComparableQuantity<Q>

    @JvmDefault
    fun consume(): Boolean {
        consumableQuantity -= quantityLostOnConsumption
        return consumableQuantity > null
    }
}

do you have a better recommendation?

[karelpeeters]

There's even something for it: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.comparisons/nulls-first.html

[karelpeeters]

No it's not clear and that's why it's not defined, what is x > null supposed to mean?

[Hullaballoonatic]

not empty

[Hullaballoonatic]

in this context

[Hullaballoonatic]

eh, i have a different idea

[Hullaballoonatic]

thanks for the advice

[karelpeeters]

That would be x != null, right?

[Hullaballoonatic]

No, because it could go below the threshold, that's fine

[Hullaballoonatic]

The effects of consumption only trigger if this function returns true

[Hullaballoonatic]

so you'd hit the consume button and nothing would happen because there's nothing to consume

[Hullaballoonatic]

internally it'd read a negative quantity, but I'll include some garbage collection

[Hullaballoonatic]

but you may be correct. i'll try to write it a little more intuitively