Scalaz 7.2 Integration

You are viewing the documentation for the older Monix 2.x series.
If you're looking for the latest 3.x click here!

Monix provides integration with Scalaz library, implementing useful type-classes for the data types exposed.

Adding the Optional Dependency

The monix-scalaz-72 is an optional dependency that you can add alongside the main Monix dependency. So in build.sbt:

libraryDependencies ++= Seq(
  "io.monix" %% "monix" % "2.3.3",
  "io.monix" %% "monix-scalaz-72" % "2.3.3"

Or maybe you want to use just Task along with this integration:

libraryDependencies ++= Seq(
  "io.monix" %% "monix-eval" % "2.3.3",
  "io.monix" %% "monix-scalaz-72" % "2.3.3"

For more details, see Usage in SBT and Maven.


You just need to import the defined implicits:

import monix.scalaz._

This will bring Monix’s type-class instances in scope. And now we can verify that Task is indeed a scalaz.Monad:

scala> import scalaz.Monad
import scalaz.Monad

scala> import monix.eval.Task
import monix.eval.Task

scala> implicitly[Monad[Task]]
res0: scalaz.Monad[monix.eval.Task] = monix.scalaz.MonixToScalaz10$MonixToScalazBindRec@ebb0aed

In case you want a more à la carte importing experience, that’s possible as well:

import monix.scalaz.monixToScalazMonad

What these imports are doing is to convert the types defined in monix.types to the Scalaz type-classes. However the convertion can also work in reverse:

import monix.scalaz.reverse._

import scalaz._
import scalaz.std.AllInstances._

Here is a reverse conversion in action, pulling a monix.types.Monad[List] out of the instances defined for Scalaz:

// res0: monix.types.Monad[List] = [email protected]

Note that having both of these wildcard imports in scope generates problems, so avoid doing it:

import monix.scalaz._
import monix.scalaz.reverse._

That’s it, now you can use the Scalaz awesome type-classes along with Monix’s abstractions, such as Coeval, Task and Observable.