In Scala collections (e.g. 2.11 or 2.12), where can I find the code that gets executed when an
val a = Array(1,2,3)
val b = a.map(_ * 5) // <--- here
That would be TraversableLike.
When methods such as map are called on arrays, an implicit conversion to ArrayOps kicks in (e.g. Predef.intArrayOps), which in turn derives these methods from SeqLike / TraversableLike through inheritance.