Does Scala have Double Side Queue similar to Java Deque or Python deque?

问题

Does Scala have Double Side Queue similar to Java Deque or Python deque?

I see only Stack and Queue in Scala 2.12 API but just want to double check.

回答1:

You can use Vector.drop or Vector.dropRight

val v = Vector(1,2,3)
v :+ 4 // Vector(1, 2, 3, 4)
0 +: v // Vector(0, 1, 2, 3)
v.drop(1) // Vector(2, 3)
v.dropRight(1) // Vector(1, 2)

回答2:

Scala 2.13 has ArrayDeque that internally uses a resizable circular buffer.

Reference:

https://downloads.lightbend.com/website/scaladays/2018/ny/slides/arraydeques-and-how-to-contribute-to-scala-2-13-collections.pdf

https://www.scala-lang.org/api/current/scala/collection/mutable/ArrayDeque.html

来源：https://stackoverflow.com/questions/49618659/does-scala-have-double-side-queue-similar-to-java-deque-or-python-deque