compile examples with java 13

build.sbt

@@ -1,20 +1,14 @@
-// this file exists only so I can have quick access to a REPL
-// with the correct dependencies.
-
-addCommandAlias("cpl", "all compile")
-addCommandAlias("fmt", "all scalafmtSbt scalafmt")
-
-scalaVersion in ThisBuild := "2.12.6"
+scalaVersion in ThisBuild := "2.12.11"
 scalacOptions in ThisBuild ++= Seq(
   "-language:_",
-  //"-Xsource:2.13",
   "-Ypartial-unification",
   "-deprecation"
 )
 
 libraryDependencies ++= Seq(
   "com.github.mpilquist" %% "simulacrum"      % "0.13.0",
   "com.chuusai"          %% "shapeless"       % "2.3.3",
+  "org.typelevel"        %% "cats-core"       % "2.0.0",
   "org.scalaz"           %% "scalaz-effect"   % "7.2.25",
   "org.scalaz"           %% "scalaz-ioeffect" % "2.10.1",
   "eu.timepit"           %% "refined-scalaz"  % "0.9.2",
@@ -32,17 +26,7 @@ libraryDependencies ++= Seq(
 )
 
 addCompilerPlugin("org.spire-math" %% "kind-projector" % "0.9.7")
-addCompilerPlugin(
-  "org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full
-)
-
+addCompilerPlugin("org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full)
 addCompilerPlugin("com.olegpy" %% "better-monadic-for" % "0.2.4")
 
 scalacOptions in (Compile, console) -= "-Xfatal-warnings"
-initialCommands in (Compile, console) := Seq(
-  "scalaz._, Scalaz._"
-).mkString("import ", ",", "")
-
-//scalafmtOnCompile in ThisBuild := true
-scalafmtConfig in ThisBuild := Some(file("project/scalafmt.conf"))
-scalafmtOnCompile in ThisBuild := true

cats.dot

@@ -0,0 +1,82 @@
+// dot cats.dot -Tpng > cats.png ; open cats.png
+digraph G {
+  rankdir = BT;
+
+  Semigroup
+  Monoid -> Semigroup
+  Band -> Semigroup
+
+  Equal
+  Show
+  Order -> Equal
+  Enum -> Order
+
+  InvariantFunctor
+  Functor -> InvariantFunctor
+  Apply -> Functor
+  Applicative -> Apply
+  Align -> Functor
+  Zip
+  Unzip
+  Bind -> Apply
+  Monad -> Applicative
+  Monad -> Bind
+  Foldable
+  Foldable1 -> Foldable
+  Traverse -> Functor
+  Traverse -> Foldable
+  Traverse1 -> Traverse
+  Traverse1 -> Foldable1
+
+  Contravariant -> InvariantFunctor
+  Divide -> Contravariant
+  Divisible -> Divide
+  Cobind -> Functor
+  Comonad -> Cobind
+  Cozip
+
+  Plus
+  PlusEmpty -> Plus
+  IsEmpty -> PlusEmpty
+  Optional
+
+  ApplicativePlus -> Applicative
+  ApplicativePlus -> PlusEmpty
+  MonadPlus -> Monad
+  MonadPlus -> ApplicativePlus
+
+  Associative
+  Bifunctor
+  Bifoldable
+  Bitraverse -> Bifunctor
+  Bitraverse -> Bifoldable
+  Compose
+  Catchable
+  Nondeterminism -> Monad
+  Category -> Compose
+  Choice -> Category
+  Split -> Compose
+  Profunctor
+  Strong -> Profunctor
+  ProChoice -> Profunctor
+  Arrow -> Split
+  Arrow -> Strong
+  Arrow -> Category
+
+  LiftIO
+  MonadIO -> LiftIO
+  MonadIO -> Monad
+  LiftControlIO
+  MonadControlIO -> LiftControlIO
+  MonadControlIO -> Monad
+  Resource
+
+  MonadState -> Monad
+  MonadError -> Monad
+  MonadTell -> Monad
+  MonadReader -> Monad
+  ComonadStore -> Comonad
+
+  BindRec -> Bind
+
+}

project/build.properties

@@ -1 +1 @@
-sbt.version=1.2.1
+sbt.version=1.3.8