How does the Cats library in Scala relate to scalaz?

72
votes

How does the Cats library relate to scalaz? The Cats project mentions it is descended from scalaz.

2
scalascalazscala-cats
The cats Gitter channel would be a much better place for a question like this, but see for example this blog post for some context from the early days of the project (i.e. two months ago). - Travis Brown

2 Answers

60
votes

I would like to keep this from getting too political*, but cats is for all intents and purposes scalaz. It has not reached full parity as of yet, but keep in mind it was only created a few months ago. The goal is for it to be a more pragmatic approach and more democratic when it comes to its evolution. So, naming of operators and classes is hopefully going to be a little more straightforward, as well as it has no qualms with using mutable data within a method if it means better performance. Last, they are HOPING to have better documentation....all of this means that it may end up becoming a replacement for scalaz with a better beginner's approach for those not embroiled in the math world. If you want a fuller answer, then maybe head over to their gitter board and Erik (non) could answer it himself :)

*The gist is that scalaz has some social baggage with it that causes a number of big names to shy away from using and/or contributing.

0
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just want to mention here that fairly recently scalaz became as well a namespace for a bunch of new, fp libraries, like testz, scalaz-zio, scalaz-metrics, scalaz-http, scalaz-analytics and more. And ScalaZ 8 is on the way!