Hi guys! Is there any way to exit-early/short-circ...

# functional

[gregd]

Hi guys! Is there any way to exit-early/short-circuit from the reduce function?
I wan’t to reduce an infinite sequence of numbers, but only until some condition is met (based on the result of the reduce).
I know Clojure has this neat reduced function for this. In Haskell we could use scan. But do we have anything similar in Kotlin’s stdlib?

[Andreas Sinz]

It depends on the surroundings, for example this short-circuits `reduce`:

fun reduced(list: Iterable<Int>): Int {
    return list.reduce { acc, item -> if(acc < 100) acc + item else return@reduced item }
}

[Uzi Landsmann]

I think people usually end up using recursion instead of reduce in these cases

[pakoito]

The implementation of reduce uses recursion, or at least the ones in arrow do. For those that are not stack-safe we have tailrecM, which are a bit more involved