does kotlin have syntactic sugar for nullable types like the for-comprehension / yield thing in Scal...

# announcements

[reik.schatz]

does kotlin have syntactic sugar for nullable types like the for-comprehension / yield thing in Scala? i.e. I have n-nullable variables and I want to yield only if they are all not null (return null otherwise)

[reik.schatz]

the only thing I can come up with are nested ?.let statements

[reik.schatz]

val out: Foo? = map["key1"]?.let { one ->
	map["key2"]?.let { two ->
		Foo(one, two)
	}
}

[reik.schatz]

scala pseudo syntax

[reik.schatz]

val foo = for {
	one <- map["key1"]
	two <- map["key2"]
} yield Foo(one, two)

[robstoll]

kotlin does not have for-comprehension. in this sense the nested let are similar to the nested flatMap which the for comprehension hides

[reik.schatz]

ok thanks

[kartoffelsup]

You can check out #C5UPMM0A0 which has comprehensions based on coroutines

[reik.schatz]

will check it out, thanks

[streetsofboston]

Those ,on Arrow, are called fx (they exist for a bunch of monadic types, eg Option, Either, IO, etc)