I'm running into deeply nested ?.let calls very often, is there something like Haskell's do notation...

# getting-started

[Bernhard]

I'm running into deeply nested ?.let calls very often, is there something like Haskell's do notation that does not require nesting but brings things into scope?

[Youssef Shoaib [MOD]]

Try out Arrow's nullable blocks

[Stephan Schröder]

maybe chain the null safe operator ?. more often!?

bob?.department?.head?.name?.let { name: String -> ... }

https://kotlinlang.org/docs/null-safety.html#safe-calls
also check your domain models, maybe they contain more nullable properties if they need to.

[CLOVIS]

Arrow's nullable block is what you're searching for:

val result = foo
  ?.let { a -> b(a) }
  ?.let { b -> c(b) }
  ?.let { c -> d(c) }

becomes

val result = nullable {
    val b = b(foo).bind()
    val c = c(b).bind()
    d(c)
}

[Bernhard]

thanks