Prefer parameters with default values last in the parameter list.

[NightlyNexus]

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)

[JakeWharton]

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.

[NightlyNexus]

truuuuue. (feel free to close if this isn't the right place for a best practices request. looking forward to that!)

[JakeWharton]

Let's start accumulating issues to track its contents. The problem was we didn't have enough content to warrant a tab when these guides were created.

…

On Fri, Jan 26, 2018 at 4:17 PM Eric Cochran ***@***.***> wrote: truuuuue. (feel free to close if this isn't the right place for a best practices request. looking forward to that!) — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#57 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAEEEdkoBlh1FEPDrOuns5q0R4KDu3FWks5tOkDagaJpZM4Ruyxb> .

[NightlyNexus]

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 = {}).