Earlier quoted context omitted.
Nicer in what sense? I do like both, I'd take either of them over Java on any day, but whereas Kotlin is maybe better suited for functional style programming (immutability out of the box, data classes etc. - however .NET people always have F# for this stuff), it's hardly on the same level as C#. For instance Kotlin doesn't have reified generics (if I recall correctly they actually attempted it, but it's too hard to g…
>Kotlin's equivalent of LINQ doesn't use deferred evaluation. Wow, I'm pretty surprised at that. Any kind of list comprehension/functional sub-language over collections seems like it ought to be deferred/lazy from the ground up. I'm doubly surprised at that from JetBrains.
Let's peek at Kotlin's sources (_Filtering.kt):
public inline fun Iterable.filter(predicate: (T) -> Boolean): List {
// note how it's allocating a new ArrayList -
// Kotlin doesn't have a "new" keyword, but it's initializing it here
return filterTo(ArrayList(), predicate)
}
public inline fun > Iterable.filterTo(destination: C, predicate: (T) -> Boolean): C {
for (element in this) if (predicate(element)) destination.add(element)
return destination
}
Note that without something like yield-return in place, writing your own collection-transforming extension functions with lazy evaluation won't be so clean and easy either
Since it has 100% interop with Java, you could work around this problem by using something like Guava - Iterables and FluentIterable are based on iterators as they should.
They use static helper methods, all you need to do is to snap out some extension functions in Kotlin to serve as bindings to Guava. The only problem, especially on Android, is that Guava's notoriously big.
Kotlin is good, I'm not hating on it, but mature? Not yet. Nicer than C#? Best of luck, but not with this type of shortcomings