Scala Tutorial

This is a collection of :

• scala scripts copied from various sources or implemented by myself while I was learning scala
• links to various projects, tutorials, plugins

Best scala books

• Programming Scala 2nd edition by Dean Wampler and Alexy Payne
• Programming in Scala by Martin Odersky
• Scala with Cats by Noel Welsh and Dave Gurnell (free e-book)
• Scala in depth by Josh Suereth

Useful links:

Scala tutorials

• Access Modifiers in Scala
• Guide to Scala Collections
• Effective scala
• Variance
• Scala cheatsheet as jupyter notebook

Scala collections

• Collection guide
• Collections tips and tricks
• Conversions between Java and Scala collections
• Stream vs. View vs. Iterator
• Performance comparison

Best practices and style guides

• Scala best practices by Nicolas Rinaudo
• Scala best practices by Alexandru Nedelcu
• Scala style guide at scala.com
• Scala style guide at databrics
• Strategic Scala Style: Principle of least power
• Design Patterns

Functional programming

• Functional Programming
• Typeclasses

Scala exercises / solutions

• Scala exercises for std lib, cats, doobie, fp in scala maintained by Underscore.io
• 99 problems in scala
• LiHaoyi's handson scala

Plugins

• scalastyle - the equivalent of checkstyle for scala (eclipse, intellij, maven, gradle)

Todo:

• common code in package objects

• function vs. method

• function composition

• structural types (duck typing), existential types

• more on variance :

  • contravariance example,
  • why immutable -> covariant and mutable -> invariant
  • type bounds vs. variance ( they're unrelated issues)

• patterns:

  • stackable traits,
  • type class,
  • evidence class,
  • cake pattern

• collections:

  • Builder, CanBuildFrom, MapLike, SeqLike
  • BigO reference for common methods in common implementations

• case classes : unapply && unapplySeq

• uniform access principle

• abstract types

• abstract types vs. parameterized types (generics)

• self type annotations

• override required and non-required

• traits can extend objects

• infix types

• unit type

• referential transparency ( see : https://pierangeloc.github.io/blog/2018/06/01/on-RT-and-FP )

• path dependent types

• type ascription

• TypeTag, ClassTag and WeakTypeTag (see: https://medium.com/@sinisalouc/overcoming-type-erasure-in-scala-8f2422070d20)

• Improve variance examples (see: https://www.benjamin.pizza/posts/2019-01-11-the-fourth-type-of-variance.html)

• F bounded types (see : http://tpolecat.github.io/2015/04/29/f-bounds.html )

• Other type bounds ( see : https://twitter.github.io/scala_school/advanced-types.html )

• improve partial functions ( see : https://blog.bruchez.name/2011/10/scala-partial-functions-without-phd.html )