In Scala I tend to favour writing large chained expressions over many smaller expressions with val assignments. At my company we've sort of evolved a style for this type of code. Here's a totally contrived example (idea is to show an expression with lots of chained calls):
import scala.util.Random
val table = (1 to 10) map { (Random.nextInt(100), _) } toMap
def foo: List[Int] =
(1 to 100)
.view
.map { _ + 3 }
.filter { _ > 10 }
.flatMap { table.get }
.take(3)
.toList
Daniel Spiewak's Scala Style Guide (pdf), which I generally like, suggests the leading dot notation in the chained method calls may be bad (see doc: Method Invocation / Higher-Order Functions), though it doesn't cover multi-line expressions like this directly.
Is there another, more accepted/idiomatic way to write the function foo above?
UPDATE: 28-Jun-2011
Lots of great answers and discussion below. There doesn't appear to be a 100% "you must do it this way" answer, so I'm going to accept the most popular answer by votes, which is currently the for comprehension approach. Personally, I think I'm going to stick with the leading-dot notation for now and accept the risks that come with it.