Is there any way to check if a Kotlin type is immu...
# announcementsa
Aaron Stacy
02/05/2020, 1:35 AMIs there any way to check if a Kotlin type is immutable at compile time (i.e. with some API in
org.jetbrains.kotlin.types<http://org.jetbrains.kotlin.ir|org.jetbrains.kotlin.ir>j
jw
02/05/2020, 1:39 AMNo. Mutable objects can, by all outward appearance, be immutable.
a
Aaron Stacy
02/05/2020, 1:41 AMSorry I should have clarified initially, I'm curious at compile time via compiler APIs.
j
jw
02/05/2020, 1:41 AMYou could guess, but it will be the halting problem very quickly.
jw
02/05/2020, 1:42 AM Copy code
class Foo {
val value get() = System.nanoTime()
} Copy code
class Bar {
val value get() = System.lineSeparator()
}jw
02/05/2020, 1:43 AMBar is by all accounts immutable, Foo is not. How do you differentiate?
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Aaron Stacy
02/05/2020, 1:43 AMYea, makes sense. I'm working on inferring stable composables in https://android-review.googlesource.com/c/platform/frameworks/support/+/1221903 , and it seems like the best way might jut be hard-coding some types like String.
j
jw
02/05/2020, 1:44 AMYeah I suspect you can get pretty far with simple heuristics
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