How should I remove the first occurrence of an object from a list in Scala?

Question

What is the best way to remove the first occurrence of an object from a list in Scala?

Coming from Java, I\'m accustomed to having a List.remove(Object o) method tha

Answer 1

You can clean up the code a bit with span.

scala> def removeFirst[T](list: List[T])(pred: (T) => Boolean): List[T] = {
     |   val (before, atAndAfter) = list span (x => !pred(x))
     |   before ::: atAndAfter.drop(1)
     | }
removeFirst: [T](list: List[T])(pred: T => Boolean)List[T]

scala> removeFirst(List(1, 2, 3, 4, 3, 4)) { _ == 3 }
res1: List[Int] = List(1, 2, 4, 3, 4)

The Scala Collections API overview is a great place to learn about some of the lesser known methods.