how does one do flow1.collect and flow2.collect in...

# coroutines

[jimn]

how does one do flow1.collect and flow2.collect in unison to combine right and left halves?

[diesieben07]

flow1.zip(flow2) { a, b -> value }?

[jimn]

the example delays creep me out a bit, but ok, i see that's viable, thanks!

[diesieben07]

Either zip or combine, depending on your needs.

[diesieben07]

https://kotlinlang.org/docs/reference/coroutines/flow.html#zip

[jimn]

the flows are Array<*>, they don't like plus ....

[jimn]

previsouly, before the zip, these were promoted to list.

Error:(333, 48) Kotlin: Cannot choose among the following candidates without completing type inference: 
public operator fun <T> Array<Any?>.plus(element: Any?): Array<Any?> defined in kotlin.collections
public operator fun <T> Array<Any?>.plus(elements: Array<out Any?>): Array<Any?> defined in kotlin.collections

[jimn]

is this a bug or a designed safety feature?

[diesieben07]

You should specify the type on a and b explicitly to help the compiler here

[jimn]

i have been wrestling with this for days, the only thing that gets me out of it is promoting to List<Any?>

[jimn]

im thinking maybe just bake in system.arraycopy, because elegant

[alllex]

@jimn You can specify exactly which of the plus implementations you need. In this case it is a.plus(elements = b)

[jimn]

SO has a thing, the spread operator is way cheaper. seems to be