What is the accepted/recommended syntax for Scala code with lots of method-chaining?

Question

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 th

Answer 1

The example is slightly unrealistic, but for complex expressions, it's often far cleaner to use a comprehension:

def foo = {
  val results = for {
    x <- (1 to 100).view
    y = x + 3 if y > 10
    z <- table get y
  } yield z
  (results take 3).toList
}

The other advantage here is that you can name intermediate stages of the computation, and make it more self-documenting.

If brevity is your goal though, this can easily be made into a one-liner (the point-free style helps here):

def foo = (1 to 100).view.map{3+}.filter{10<}.flatMap{table.get}.take(3).toList
//or
def foo = ((1 to 100).view map {3+} filter {10<} flatMap {table.get} take 3).toList

and, as always, optimise your algorithm where possible:

def foo = ((1 to 100).view map {3+} filter {10<} flatMap {table.get} take 3).toList
def foo = ((4 to 103).view filter {10<} flatMap {table.get} take 3).toList
def foo = ((11 to 103).view flatMap {table.get} take 3).toList