You need to check `categories = null` The compiler cannot in kotlinlang #announcements

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Title

m

marstran

07/30/2018, 12:41 PM

You need to check

categories != null

. The compiler cannot infer that it's not null from the

.orEmpty().isEmpty()

call.

👍 1

m

mp

07/30/2018, 12:42 PM

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

this one a bit verbose but also clear for compiler

m

marstran

07/30/2018, 1:06 PM

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 {
        ...
    }
}

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