494. The QR encoder is an image format

Date: 2026-09-30

Status

Accepted. Moves the package ADR-0391 created and changes nothing else it decided.

Context

ADR-0391 put the QR encoder in :core “beside image.gif and image.png and for their reason”. Each is a specification small enough that owning it costs less than linking it, with nothing in it that names a widget. The package it was given was not beside them, though. It was io.github.digitalsmile.goldberry.qr, a top-level package among css, layout, paint and render, which are the toolkit’s subsystems. The encoder is not a subsystem. It takes a payload and returns a QrMatrix, the same shape of thing as the GIF decoder and the PNG encoder.

ADR-0172 says a package is named for the role its contents play. The role is “an image format the toolkit owns”, and that role already has a parent package.

Decision

…goldberry.qr is …goldberry.image.qr. All eleven types, the five tests and libqrencode-vectors.txt move with it, unchanged. :core exports the new name in place of the old. :widgets’ qr-code and the showcase’s Canvas screen import it from there.

tools/refactor/move_package.py made the move. On the way it was found to walk into .claude/worktrees/, which holds agents’ whole-repository worktrees, and would have rewritten another agent’s copy. It now skips .claude.

Consequences

• A source-incompatible change for an application that imported io.github.digitalsmile.goldberry.qr. Nothing has been released, so there is no deprecation shim. The snapshot is the only place the old name ever shipped.
• image now holds every format the toolkit owns: gif, png, anim, qr.

Alternatives considered

• image.codec.qr, with gif and png moved under codec as well. It would be tidier, but it would churn two more exported packages for a word that adds nothing. The parent is already image.