User-visible changes
- Cancel button — terminates the running worker. Pyodide's slow mandelbrot
no longer freezes the UI; click cancel and the elapsed counter freezes
at "(cancelled @ NNNN ms)".
- Live ms counter ticks per animation frame while a tier is busy, so the
Pyodide tier's ~5-15 s wait is visible instead of looking hung.
- Restyled to match lumbda.com: chunkfive wordmark, --green: #227842
(light) / #5ec07a (dark), lumbda-logo-green.png, lowercase "lumbda"
everywhere. Pulls fonts/chunkfive locally so the playground stays
self-contained.
Architecture
- All tier evaluations now run inside a Web Worker (wasm/app/worker.mjs)
so the main thread stays responsive. Cancel = worker.terminate(); next
eval respawns a fresh worker.
- Loaders use new URL("./...", import.meta.url) so paths resolve against
the loader file's own location — works identically in window and
worker contexts, no baseURL argument needed.
- C tier Emscripten build flipped to EXPORT_ES6=1; loader uses dynamic
`import()` of the factory module. Integration test updated accordingly.
- Python loader uses `import("pyodide.mjs")` (ES module) instead of
document.createElement, which doesn't exist in workers.
Bug fixes
- Asm tier state leak: running the same demo twice on a cached WASM
instance produced corrupted output (every other cell on row 2+ rendered
as " " instead of the expected shade char). Root cause: top-level eval
passed `global_env` as the env, so closures captured stale globals;
fixed by passing NIL — env_lookup falls back to the CURRENT global_env
via its existing two-pass walk. Multi-run regression added to the
functional test suite.
- fib-ack demo: (ack 3 4) was too heavy for Pyodide (minutes). Cut to
(ack 3 3) + (fib 20) max so every tier finishes in seconds.
Test discipline
- Root `make test-all` now includes `wasm-test`. Adding a language
feature without exercising it on all six implementations is no longer
possible by accident.
- Functional suite: 11 assertions (was 10) — adds asm multi-run stability.
- Integration + unit: still 20 + 8.
Adds a parallel build of all three Lumbda implementations to WASM, a
single-page playground at www/playground/, and a verified test suite.
Tiers
- Python: Pyodide (CPython-in-WASM) hosting lumbda.py
- C: Emscripten build of c/ (tree-walker + bytecode VM; jit.c
stubbed, gc.c uses its existing no-Boehm fallback)
- Asm: hand-written asm/lumbda.wat — parallel impl to asm/lumbda.s.
Reader, eval (lambda/define/if/cond/let/and/or/quote/set!),
recursion across mutated top-level env, bump allocator with
memory.grow, 24 primitives. ~1200 lines of raw WAT.
SPA (wasm/app/, deployed to www/playground/)
- CodeMirror 6 editor (Scheme highlighting) on left, output on right
- Radios: 4 demos (Mandelbrot, Fib+Ack, Sieve, self-interp meta-eval)
x 4 tiers (Python | C | Asm | All three)
- All-three mode renders the three tier outputs side by side with
per-tier elapsed timing
Tests (38 verified assertions)
- 20 unit (Node): per-tier module loads, eval smoke
- 8 integration (Node): each demo on c+asm WASM byte-matches the
canonical native Python run
- 10 functional (Playwright headless Chromium): page mounts, every
demo runs on every tier, all-three renders
Makefile
- Root targets: wasm-build, wasm-test, wasm-test-fn, wasm-serve,
wasm-deploy, wasm-clean
- wasm/Makefile orchestrates the three tier builds; deploy copies
dist/ into www/playground/
Asm tier notes
- WAT linear symbol intern + linear env lookup is MOAD-0001 at scale;
documented in the asm/lumbda.wat header and in the SPA footer. The
demos hit ~30 globals so the linear walks are cheap enough.
- Bump allocator never frees (matches asm/lumbda.s heap discipline);
memory.grow expands by 1 MB chunks. Browser tab tears down at unload.
Toolchain (developer prerequisites)
- Emscripten 6.0.0 via emsdk at ~/git/emsdk
- wabt 1.0.36 at ~/git/wabt
- Playwright for functional tests (symlinked from ~/git/agnt)
