Introduction

Stream is essentially a fancy Iterator. It implements custom API, which is similar to Iterators's, but is faster and fully specialized for primitives

Once Stream is enabled, Scala collections receive a new implicit method .all, which returns Stream of all collection elements:

import scalqa.Stream.Enable._

val list = (1 to 1000).toList

list    .filter(_ % 2 == 0).flatMap(_ => list).map(_ / 2L).sum
list.all.filter(_ % 2 == 0).flatMap(_ => list).map(_ / 2L).sum

The above two statements calculate same value, but first is done with native List methods, the second uses Stream, which in this case is over 500% faster

If one types .all before doing heavy data transformations, the program will run faster, while using less memory

Calling <collection>.all is similar to creating lazy view with <collection>.view, except Stream is faster and specialized

Generally Scalqa/Stream framework can be useful in 3 different scenarios:

Stream can be an extension of Scala collections to get performance advantage
Stream could be created for custom source to process data in fast and consistent manner
Basic collections, which come with the framework, can occasionally replace Scala's

Introduction 

Introduction