One thing I snuck in while covering the reader monad is the Applicative builder |@|. On day 2 we introduced ^(f1, f2) {...} style that was introduced in 7.0.0-M3, but that does not seem to work for functions or any type constructor with two parameters.
The discussion on the Scalaz mailing list seems to suggest that |@| will be undeprecated, so that’s the style we will be using, which looks like this:
scala> (3.some |@| 5.some) {_ + _}
res18: Option[Int] = Some(8)
scala> val f = ({(_: Int) * 2} |@| {(_: Int) + 10}) {_ + _}
f: Int => Int = <function1>