`IntRange.forEach` uses `Iterable.forEach`, so `(1...

# stdlib

[Derek Peirce]

IntRange.forEach uses Iterable.forEach, so (1..n).forEach { ... } creates an Iterator, while for (k in (1..n)) { ... } is optimized to use a while-loop, not even creating the original IntRange object. Could IntRange receive its own forEach extension method to preserve this optimization, and perhaps receive additional optimizations for common methods like map?

[Ruckus]

Those are a little different. The for loop optimization is a compiler intrinsic, not a library function.

Not that it invalidates your request, just that I don't think the two are very related.

[ilya.gorbunov]

https://youtrack.jetbrains.com/issue/KT-18802

[Derek Peirce]

@Ruckus it's a compiler intrinsic that a specialized inline function would be able to take advantage of, unlike an Iterable extension function.