Files
wickra/examples/wasm
kingchenc 677ea37402 examples: migrate to the native data layer (drop ws/coder-websocket/jackson/jsonlite) (#316)
Stacked on #315 (the native Binance REST fetcher). Retarget to `main` once #315 merges.

Migrates the runnable examples off third-party data-I/O packages onto Wickra's
native data layer (`CandleReader`, `Resampler`, `BinanceFeed`, `fetch_*klines`).

## Third-party packages removed (the zero-dep selling point)
- **Node**: `ws` (live feed → BinanceFeed) — dropped from package.json + lockfile
- **Go**: `github.com/coder/websocket` — dropped from go.mod / go.sum (`go mod tidy`)
- **Java**: `jackson-databind` (live feed + REST fetch) — dropped from pom.xml
- **R**: `jsonlite` + `websocket` + `later` — dropped from the README notes

Each language's CSV loading now goes through `CandleReader`, manual resampling
through `Resampler`, the live feed through `BinanceFeed`, and (Java/R) the REST
download through the native fetcher.

## Verification
Ran the offline examples per language against the bundled data — backtest and
multi_timeframe produce identical output across Python / Node / Go / Java / R
(e.g. ATR(14) last 345.1010; 1h→5m resamples to 240 bars, →15m to 80 bars).

C# / C / WASM (stdlib-only, no third-party deps to remove) follow in this branch.

Note: the streaming `strategy_*` examples have pre-existing candle-indicator
runtime bugs (CI only syntax-smokes them); the CSV migration preserves their
shape and leaves those bugs for a separate fix.
2026-06-17 01:49:11 +02:00
..

Wickra WASM examples

Browser demos for the wickra-wasm WASM binding. Every demo loads the module the same way (init() then construct indicators) so the patterns transfer one-to-one to your own page.

Build

The WASM module ships as a wasm-pack --target web bundle. Build it once from the repository root:

wasm-pack build bindings/wasm --target web --release --features panic-hook

This drops bindings/wasm/pkg/ with the .wasm binary, the JS loader and TypeScript types. Every demo here imports the loader via ../../bindings/wasm/pkg/wickra_wasm.js.

Serve

ES-module workers and fetch() over CSV both need a real HTTP origin, not file://. Any static server from the repository root works:

# Python:
python -m http.server 8000

# Or Node:
npx http-server -p 8000

Then open the demo you want at http://localhost:8000/examples/wasm/<file>.

Demos

File What it does
index.html The original showcase: streams a synthetic price series through six indicators and draws a live <canvas> chart with SMA, EMA, RSI, MACD, BollingerBands and ATR cards.
backtest.html Backtest: fetches an OHLCV CSV (default the bundled BTCUSDT daily dataset), streams every candle through a basket of eight indicators, prints a summary table. Mirrors examples/python/backtest.py.
live_binance.html Browser-native WebSocket to Binance kline streams; runs RSI / MACD / Bollinger on the incoming closes and flags BUY/SELL candidates when the three agree. Mirrors examples/python/live_binance.py.
multi_timeframe.html Fetches a 1-minute CSV, rolls it up in-page to 5m / 15m / 1h / 4h / 1d buckets and prints RSI / MACD-histogram / ADX per timeframe. Mirrors examples/python/multi_timeframe.py.
parallel_assets.html Synthetic (assets, bars) panel, serial baseline on the main thread vs. a pool of module Workers each loading its own copy of the WASM module. Mirrors examples/python/parallel_assets.py.
parallel_worker.js Module worker used by parallel_assets.html (not loaded directly).
strategy_rsi_mean_reversion.html RSI(14) mean-reversion (long < 30, exit > 70), 0.1% fees, summary table. Mirrors examples/python/strategy_rsi_mean_reversion.py.
strategy_macd_adx.html MACD(12,26,9) crossover gated by ADX(14) > 20, summary table. Mirrors examples/python/strategy_macd_adx.py.
strategy_bollinger_squeeze.html Bollinger-squeeze breakout with a 2×ATR(14) stop, summary table. Mirrors examples/python/strategy_bollinger_squeeze.py.

Performance

The in-browser benchmark is parallel_assets.html: it times a serial main-thread baseline against a pool of module Workers and reports the speedup. For raw single-thread throughput numbers see the sibling benchmarks — Rust criterion (crates/wickra/benches/), Python (bindings/python/benchmarks/compare_libraries.py) and Node (bindings/node/benchmarks/throughput.js, npm run bench). The WASM engine is the same Rust core compiled to wasm32, so its relative ordering of indicators tracks those.

See also

  • Quickstart: WASM — module-load flow, wasm-pack targets, and the streaming API.
  • examples/README.md — cross-language index, including the Rust, Python, Node.js, C and C# siblings of every demo above.