Essential Scala Dojo

Most of the examples and exercises are come from underscore’s books

• https://underscore.io/books/essential-scala/
• https://underscore.io/books/scala-with-cats/
• https://underscore.io/books/shapeless-guide/

Up and Running

Execute the following command so your sbt can download packages in multi threads

mkdir -p ~/.sbt/1.0/plugins
echo 'addSbtPlugin("io.get-coursier" % "sbt-coursier" % "1.0.0")' >> ~/.sbt/1.0/plugins/plugins.sbt

Run sbt

sbt

Then type compile and wait all deps download and everything should compile.

If everything compiled, try typing in test command

Challenges

All the exercises are well documented and defined in files under test folder.

Basically just make the following tests compile and all green…

1-class-and-object.scala
2-1-algebraic-data-type.scala
2-2-recursive-data-type.scala
2-3-variance.scala
2-4-typeclasses.scala
2-5-type-enrichment.scala
3-1-functor.scala
3-2-identity-monad.scala
3-3-reader-writer-monad.scala
3-4-state-monad.scala
3-5-monad-transformer.scala
3-6-semigroupal.scala
3-7-validated.scala
3-8-traverse.scala
4-1-kind.scala
4-2-free.scala

all the tests are actually generated from following literal programming org files

• https://github.com/jcouyang/scala-dojo/blob/master/src/test/scala/2-typeclasses.org
• https://github.com/jcouyang/scala-dojo/blob/master/src/test/scala/3-monad.org
• https://github.com/jcouyang/scala-dojo/blob/master/src/test/scala/4-1-kind.org
• https://github.com/jcouyang/scala-dojo/blob/master/src/test/scala/4-2-free.org

Typeclasses Coverage

More Challenges

• Type-level Programming with Shapeless by Ben Hutchison