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kotlinlang

You need to check `categories != null`. The compiler cannot infer that it's not null from the `.orEmpty().isEmpty()` call.

it have two thoughts about this case. and yes - first  was that i want too much from compiler. but second - I miss something

tnx

image.png

this one a bit verbose but also clear for compiler

Yes, because you capture the result of the `orEmpty` call with the `with` function. The receiver inside `with` is non-null.

In your first example, you throw away the result of `categories.orEmpty()`. You could do this to fix it:
```
val nonNullCategories = categories.orEmpty()
if (nonNullCategories.isEmpty()) {
    0
} else { 
    nonNullCategories.map {
        ...
    }
}```