Is there a more idiomatic way than aborting a loop...

# codingconventions

[Marc Knaup]

Is there a more idiomatic way than aborting a loop if needed and returning null if it completes?

interface Foo
interface FooProvider { fun provide(): Foo? }

fun provideFoo(providers: List<FooProvider>): Foo? {
	for (provider in providers)
		provider.provide()?.let { return it }

	return null
}

I miss something like providers.firstNonNullMapped { it.provide() } (and with a better name).

[arekolek]

providers.asSequence().mapNotNull(FooProvider::provide).firstOrNull() ?

[Marc Knaup]

That’s one way, yes 🤔

Just a little long and with multiple intermediary objects created.

[Shawn]

it’s like three chained method calls, and the sequence operations are optimized pretty well by the compiler

[Shawn]

I wouldn’t stress about it.

[Matteo Mirk]

Exactly, also if you don’t like the verbosity of that expression or you need to use it in many places, just encapsulate it in an extension function

[Tobias Berger]

that's what I did in a current project. I just wrote my own mapFirstNotNull extension method that does the returning loop

[Mike]

asSequence avoids creating intermediary collections IIRC.