Longevity Goes Finally Tagless

Longevity - your persistence framework for Scala and NoSQL - has always sported a future-based API. But now in release 0.24, longevity has gone finally tagless, replacing the hardcoded references to scala.concurrent.Future with a generic effect F. We currently support three effects: Scala futures, the cats-effect IO monad, and an old-fashioned blocking API for the purists out there. We plan to support a variety of Task monads as effects in the near future, and you can always write your own effect as well.

For more information on longevity effects, see the user manual.

For examples on how longevity works with different effects, check out this demo code.

This release is exciting for me for many reasons. Perhaps most importantly, longevity now sports a truly functional API with support for IO monads. But the flexibility of the finally tagless approach is truly freeing. We can satisfy the purist functional programmers, and continue to support people who want to do reactive programming with futures, with a minimum of cognitive overhead. It's also exciting to me because it's a major step on my personal path to becoming a better functional programmer.

But the best part for me is just how beautiful the repository API has become. Just look at it. In a sense, this is how this API was always meant to be. Perfectly intuitive, fully typesafe, just the right level of abstraction without a hint of leaks. I couldn't imagine doing persistence in Scala any other way.