Prefer parameters with default values last in the parameter list.
Opened this issue · 4 comments
https://android.github.io/kotlin-guides/interop.html#function-overloads-for-defaults
mentions this but in a different context.
This is useful even in pure Kotlin, regardless of Java interop because it doesn't require naming the other parameters at the call site.
data class Pizza(val cheese: Boolean, val toppings: List<String> = listOf())
Pizza(true)
instead of
data class Pizza(val toppings: List<String> = listOf(), val cheese: Boolean)
Pizza(cheese = true)
We can't add this to the style guide because I don't think we can make it a hard rule. But it's a good candidate for a hopefully forthcoming best practices / patterns section.
truuuuue. (feel free to close if this isn't the right place for a best practices request. looking forward to that!)
One notable exception is lambdas. Lambdas are a higher priority for being last in the parameter list.
fun foo(unused: Any? = null, a: (String) -> Unit) {}
foo {} works here without needing to name the a parameter. That is, no need for foo(a = {}).