Scala filter on two conditions

Question

I would like to filter my data set on two conditions at once.

Is it possible?

I want something like this:

mystuff = mystuff.filter(_.isX &         


        

Answer 1

If you need to frequently filter with several predicate, you could define a way of combining them:

case class And[A]( p1: A=>Boolean, p2: A=>Boolean ) extends (A=>Boolean) {
  def apply( a: A ) = p1(a) && p2(a)
}

Here is how to use it to keep only the odd numbers bigger than 10:

scala> (0 until 20) filter And( _ > 10, _ % 2 == 1 )
res3: scala.collection.immutable.IndexedSeq[Int] = Vector(11, 13, 15, 17, 19)

It easy to write Or and Not combinators in the same fashion.