gfc-collective / gfc-collection   1.0.0

Apache License 2.0 GitHub

A library that contains Scala collection utility classes

Scala versions: 2.12 2.13

gfc-collection Maven Central Build Status Coverage Status

A library that contains scala collection utility classes. A fork and new home of the now unmaintained Gilt Foundation Classes (com.gilt.gfc), now called the GFC Collective, maintained by some of the original authors.

Getting gfc-collection

The latest version is 1.0.0, released on 21/Jan/2020 and cross-built against Scala 2.12.x and 2.13.x.

If you're using SBT, add the following line to your build file:

libraryDependencies += "org.gfccollective" %% "gfc-collection" % "1.0.0"

For Maven and other build tools, you can visit (This search will also list other available libraries from the GFC Collective.)

Contents and Example Usage


Simple non-thread-safe circular buffer implementation that supports adding a new item, finding the oldest item, the newest item, or iterating from oldest to newest.

val buffer = new CircularBuffer[Int](5)

assert(buffer.oldest == 0)
assert(buffer.newest == 0)
assert(buffer.size == 1)

(1 to 4).foreach(buffer.add(_))
assert(buffer.oldest == 0)
assert(buffer.newest == 4)
assert(buffer.size == 5)

assert(buffer.oldest == 1)
assert(buffer.newest == 5)
assert(buffer.size == 5)


Utility to select top N items from a collection.

val numbers = scala.util.Random.shuffle(0 to 1000)
assert(TopN(5, numbers) == Seq(0, 1, 2, 3, 4))
assert(TopN(5, numbers)(scala.math.Ordering.Int.reverse) == Seq(1000, 999, 998, 997, 996))


Licensed under the Apache License, Version 2.0: