Symbolator Python Worker

This unit preserves the useful Symbolator HDL component workflow while removing the native desktop dependencies from the Kroki binary. It accepts Verilog / SystemVerilog module declarations and VHDL entities/components, preserving generics, grouped ports, directions, buses, clock markers, bubbles, titles, scaling, and type labels.

The pinned Kroki Symbolator 1.2.2 package cannot be imported directly into a Python Worker: its SVG backend imports gi, Cairo, and Pango for text metrics. Those native bindings are not Pyodide packages. This unit is therefore a small translation/rendering path with deterministic approximate text metrics. Font metrics and exact layout may differ from the native renderer; that loss is intentional and documented so coverage can move off the Java image.

The unit has no filesystem, subprocess, or network access. The hostname selects the renderer; the request body cannot select an engine.

Local checks

uv run pytest -q
uv run pywrangler sync
uv run pywrangler dev --port 8791

Known losses

• Native Pango font shaping is replaced by conservative monospace-like width estimates. SVG text remains selectable and uses browser fonts.
• The native command's library-directory scanning and persisted array-type cache are intentionally unavailable; requests contain one HDL source.
• PNG/PDF/PS/EPS output is not supported by the Worker plane; SVG is supported.