dfa11

Dictionary Compression for Microservices notes

> Underengineering (I just invented this term): Too little engineering and too few patterns for a complex problem.

actually this is well-known: like a PoC that goes to production...

yeah 100% agree! In some critical area, I'm forced to drop all the "good things" and pack 2 shorts into 1 int to build a tuple(short,short)...

True: this compiles and the test passes today on JDK 27-jep401ea3:

  record Person(String name, Age age, Iban iban) {}

  // {"name": "SuperMario", "age": null, "iban": null}
  Person result = mapper.readValue(json, Person.class);

  assertThat(result.age()).isNull();   // passes — value class field, null
  assertThat(result.iban()).isNull();  // passes — value class field, null

  Jackson bypasses the constructor for null JSON tokens (getNullValue() short-circuits), so the
  validation in new Age(...) never runs. Both Age and Iban are value classes; both fields are null.

What do you think? Of course, there are limitations as Person cannot be flattened anymore but I guess Valhalla will ship more JEPs later?

Valhalla removes the historical performance tax on tiny domain objects. This article argues that value classes finally make domain‑safe primitives practical in real systems — strong invariants, flat layout, no wrapper overhead.

I’d love feedback from folks who’ve experimented with Valhalla or have opinions on modelling domain types in Java.

this is really interesting +1 star

PS is there a plan to include hermetic builds, from local sources / git submodules?