A Library for Reactive Collections
Polix is a Scala library that abstracts over consecutive changes made to an imaginary mutable collection. The main goal of the library is to aid the usage of collections in Functional Reactive Programming (FRP).
It loosely based on the design patterns shown in the 2013 Paper Higher-Order Reactive Programming with Incremental Lists, by Ingo Maier and Martin Odersky, but it aims to be agnostic in regards to the streaming library used, instead of providing it's own implementation.
Polix provides a set of types each representing a collection similar to those found in the scala.collection library.
For example a Sequence can be represented by the RSeq type.
It's usage is analogous to scala's Seq, with the difference that each operator returns a view on the original RSeq,
with the operator applied to all changes made to that original collection.
val input: VBuffer[Double, Subject] = VBuffer[Double](PublishSubject)
val output: RSeq[Double, Observable] = input.map(n => n * 2)
val result: Observable[RSeqEvent[Double]] = output.stream
result.foreach(println)
input += 1 // => Append(2)
input += 2 // => Append(4)
input.prepend(0) // => Prepend(0)
input.insert(2, 1.5) // => Insertion(2, 3)
input ++= List(10, 11, 12) // => AppendAll(List(20, 22, 24))
input.patch(4, List(5, 6, 7), 0) // => Patch(3, List(10, 12, 14), 0)To input into an RSeq you can either create one directly from an Observable[RSeqEvent] using RSeq.lift(source),
or you can use a VBuffer which is analogous to a scala.collection.mutable.Buffer and can be created by supplying any Subject.
At the moment, the library is still very much a Work in Progress and serves mainly as a Proof of Concept until a Structure is found that satisfies all points made in the Design Goals section.
WIP