Scala's for-comprehensions: vital feature or syntactic sugar?

Question

When I first started looking at Scala, I liked the look of for-comprehensions. They seemed to be a bit like the foreach loops I was used to from Java 5, but with functional rest

Answer 1

Another great use of for-comprehension is for internal DSL. ScalaQL is a great example of this. It can turn this

val underAge = for { 
  p <- Person 
  c <- Company 
  if p.company is c 
  if p.age < 14 
} yield p 

into this

SELECT p.* FROM people p JOIN companies c ON p.company_id = c.id WHERE p.age < 14 

and a whole lot more.