jadireddi / collection-strawman

Experimenting with Scala Collections designs for Scala 2.13

Collection-Strawman

Prototype improvements for Scala collections.

• Gitter Discussion
• Dotty Issue
• Scala Center Proposal

Use it in your project

We published a 0.1.0 version so that you can experiment with the new design. Note that most of the collection implementations are incomplete!

libraryDependencies += "ch.epfl.scala" %% "collection-strawman" % "0.1.0"

Only Scala 2.12 is supported so far.

We also automatically publish snapshots on Sonatype:

resolvers += Resolver.sonatypeRepo("snapshots")

libraryDependencies += "ch.epfl.scala" %% "collection-strawman" % "0.2.0-SNAPSHOT"

Implemented collection types

• List
• LazyList (aka Stream in 2.12)
• Queue
• Stack
• ArrayOps
• StringOps
• ArrayBuffer
• ListBuffer
• UnrolledBuffer
• LinkedList
• DoubleLinkedList
• Range / NumericRange
• Vector
• HashMap
• TreeMap
• IntMap / LongMap (?)
• ListMap
• MultiMap
• HashSet
• ListSet
• TreeSet
• EqSet
• BitSet
• View

Implemented operations (on the relevant collection types)

Operations not returning a collection

• apply
• contains
• firstKey
• forall
• foreach
• foldLeft
• foldRight
• get
• head
• indexWhere
• isDefinedAt
• isEmpty / nonEmpty
• keysIteratorFrom
• last
• lastKey
• mkString
• size
• sum
• to

Transformations to collections having the same element type

• drop
• empty
• filter / filterNot
• groupBy
• intersect
• partition
• range
• rangeImpl
• slice
• splitAt
• tail
• take
• updated

Transformations to collections that can have a different element type

• ++ / concat / union
• flatMap
• map
• merged
• zip

In-place mutating operations

TODO