why doesn't this compile: ```val countries by remember { listOf(Locale.getISOCountries().map { Local...

# compose

[Sam]

why doesn't this compile:

val countries by remember { listOf(Locale.getISOCountries().map { Locale("", it) }) }

with exception: Type 'TypeVariable(T)' has no method 'getValue(Nothing?, KProperty<*>)' and thus it cannot serve as a delegate

[Ian Sikes]

maybe try mutableListOf?

[Sam]

does not work either @Ian Sikes

[Sam]

i suspect i have a misunderstanding with how to store lists in state with remember but i can't find any examples

[Ian Sikes]

how about mutableStateListOf? haha I haven't quite got it either. The codelabs seem to cover mutableStateOf but not these other uses

[Zach Klippenstein (he/him) [MOD]]

mutableStateOf returns a MutableState, which has getValue (and setValue) defined as extension functions, which is why that works.

[Zach Klippenstein (he/him) [MOD]]

remember just returns whatever you return from the lambda – it doesn’t change the type. So if what you’re returning can’t act as a delegate, this won’t work.

[Sam]

so is the solution to use mutableStateOf even for lists?

[Zach Klippenstein (he/him) [MOD]]

Neither List nor SnapshotStateList can be delegates

[Zach Klippenstein (he/him) [MOD]]

so is the solution to use mutableStateOf even for lists?

Yes, the list is your state here.

[Zach Klippenstein (he/him) [MOD]]

Although you only need to do that if you actually need to change it. If you don’t, just remembering the list directly is fine, but then use = instead of by.

[Sam]

that's what i was about to ask, since the list here is immutable.. just want to make sure it doesn't recalculate the map transform on every render

[Zach Klippenstein (he/him) [MOD]]

It won’t, anything in the remember lambda will only be executed once