As described by Patrick Wendell of Data Bricks in his Scala Days 2015 presentation.
I cannot thank you enough for your book, Atomic Scala. It is EXACTLY what I needed: a beginner’s programming book without comparisons to Java code on every other page. I was previously working on “Functional Programming in Scala” and it was too advanced for me! Though I am an experienced R user, Scala will actually be my first programming language. — Jonnie Lappen