Reassigning Variables via Destructuring

Question

I love Kotlin's destructuring features, they help me to declutter code and focus on the essential.

I encountered a case for which I could not figure out the correct syntax, how can I reassign variables via destructing?

var (start, end) = startEndDate(198502)

// intellij neither accept this ...
start, end = startEndDate(200137)

// ... nor this
(start, end) = startEndDate(200137)

Answer 1

From the language perspective, the variables declared in destructuring declaration are just separate independent variables, and at the moment Kotlin doesn't provide a way to assign multiple variables in a single statement.

You can only destructure your expression again and assign the variables one by one:

var (start, end) = startEndDate(198502)

val (newStart, newEnd) = startEndDate(200137)
start = newStart
end = newEnd

---

If you need to show that these two variables have have some special meaning and should be assigned together, you can declare a local function that reassigns them like this:

var (start, end) = startEndDate(198502)
fun setStartEnd(pair: Pair<SomeType, SomeType>) { start = pair.first; end = pair.second }

setStartEnd(startEndDate(200137))