Patternia v0.6.3 Release Note

Release Date: January 2, 2026 Version: 0.6.3

---

Overview

Patternia v0.6.3 was an intermediate cleanup release on the path away from the old builder-heavy API.

This page has been normalized to the current API surface. The original release note focused on left-value chained builder mutation, which is no longer part of the repository.

---

Highlights

Fewer Staging Forms

The design direction in this release was to reduce partially mutated builder states and push users toward one-shot case assembly.

That direction is now complete in the current API:

using namespace ptn;

int classify(int value) {
  return match(value) | on(
    lit(1) >> "one",
    lit(2) >> "two",
    _ >> "other"
  );
}

Simpler Evaluation Flow

By moving away from incremental builder mutation, the implementation can keep case ordering, fallback rules, and diagnostics localized to one explicit case pack.

Why This Note Still Exists

v0.6.3 matters historically because it shows the library already moving away from mutable chained state. Later cleanups removed that builder surface entirely.

---

Historical Note

The original v0.6.3 page documented staged builder mutation and related termination helpers. Those APIs have since been removed in favor of the single pipeline form match(subject) | on(...).