2018-07-04

Two Major Design Flaws

Throughout the time I spent developing longevity, I've made any number of major design flaws. The vision I started out with has changed drastically over time. It's evolved as I experimented with developing the longevity API. While my core guiding principles have stayed in place, the early versions of the library are nearly unrecognizable when compared to the latest version.

Since the beginning, I've had a comprehensive test suite, that has allowed me to correct mistakes and simplify my API with ease and assurance of correctness. And working with the API as it has grown has allowed me to spot problems as I moved forward. But there were two major design flaws that remain in place. Both of them have been nagging me for many months now, until they have become clear in my head. Now I'm ready to admit and address these two errors: the failure to use shapeless, and the lack of column-oriented storage of persistent entities with column-oriented back ends such as Cassandra and SQLite.

2018-07-03

Longevity 0.27 - Stepping into Shapeless

After over 8 months since it's previous release, longevity version 0.27 is out! This release is very exciting to me, as it represents longevity's first steps into shapeless. I was able to incorporate shapeless.Generics into the domain model for all of the persistent objects, which will allow me to replace home-grown reflection based code with shapeless going forward.

The externally facing changes are minor. I've replaced a home-grown test data generation tool with ScalaCheck and scalacheck-shapeless. However, this minor change has already reaped benefits, as it replaces a particularly ugly part of the old longevity API - custom generation of test data - with a much more elegant process of supplying the right implicit org.scalacheck.Arbitrary.

This minor feature is really a proof of concept that I would be able to replace my homegrown reflective code with shapeless features. I feel confident that I can migrate the entire architecture over. Although of course, it will take some time. I will write more soon on how I plan to move forward from here. Stay tuned!