Merge worktree-agent: add struct literals, generics, print/log builtins

crates/el-wasm/js/runtime.js

@@ -0,0 +1,72 @@
+// Engram-lang WASM runtime loader
+// Include this in any web app to run .el programs natively in the browser.
+//
+// Usage:
+//   import { initRuntime, runElc, evalSource } from '/js/runtime.js';
+//
+//   await initRuntime();
+//   const result = await runElc('/programs/main.elc');
+
+let wasmModule = null;
+
+/**
+ * Initialise the engram-lang WASM runtime. Safe to call multiple times —
+ * subsequent calls return the already-loaded module immediately.
+ *
+ * @param {string} wasmUrl - Path to the .wasm file (default: /pkg/el_wasm_bg.wasm)
+ * @returns {Promise<object>} The loaded runtime API
+ */
+export async function initRuntime(wasmUrl = '/pkg/el_wasm_bg.wasm') {
+    if (wasmModule) return wasmModule;
+
+    const { default: init, compile_source, load_and_run, eval: elEval, version } =
+        await import('/pkg/el_wasm.js');
+
+    await init(wasmUrl);
+
+    wasmModule = { compile_source, load_and_run, eval: elEval, version };
+    console.log(`engram-lang WASM runtime v${version()} loaded`);
+    return wasmModule;
+}
+
+/**
+ * Fetch a pre-compiled .elc file from the server and execute it.
+ *
+ * The browser caches the .elc file automatically based on Cache-Control
+ * headers set by the server. New bytecode is available immediately on the
+ * next fetch — no app-store review required.
+ *
+ * @param {string} elcUrl - URL of the .elc bytecode file
+ * @returns {Promise<any>} The JSON-deserialised result value
+ */
+export async function runElc(elcUrl) {
+    const rt = await initRuntime();
+    const response = await fetch(elcUrl);
+    if (!response.ok) throw new Error(`Failed to fetch ${elcUrl}: ${response.status}`);
+    const bytes = new Uint8Array(await response.arrayBuffer());
+    return JSON.parse(rt.load_and_run(bytes));
+}
+
+/**
+ * Compile engram-lang source and run it immediately. Useful for REPL and
+ * developer-mode execution where source is available at runtime.
+ *
+ * @param {string} source - Engram-lang source code
+ * @returns {Promise<any>} The JSON-deserialised result value
+ */
+export async function evalSource(source) {
+    const rt = await initRuntime();
+    return JSON.parse(rt.eval(source));
+}
+
+/**
+ * Compile engram-lang source to bytecode bytes without running it.
+ * The returned Uint8Array can be stored or uploaded as a .elc file.
+ *
+ * @param {string} source - Engram-lang source code
+ * @returns {Promise<Uint8Array>} Compiled bytecode bytes
+ */
+export async function compileSource(source) {
+    const rt = await initRuntime();
+    return rt.compile_source(source);
+}