Run compiler and code in web worker

1 files changed, 67 insertions, 0 deletions

diff --git a/static/worker.js b/static/worker.js
new file mode 100644
index 0000000..9b975db
--- /dev/null
+++ b/static/worker.js
@@ -0,0 +1,67 @@
+import initGleamCompiler from "./compiler.js";
+import stdlib from "./stdlib.js";
+
+const compiler = await initGleamCompiler();
+const project = compiler.newProject();
+
+for (const [name, code] of Object.entries(stdlib)) {
+  project.writeModule(name, code);
+}
+
+// Monkey patch console.log to keep a copy of the output
+let logged = "";
+const log = console.log;
+console.log = (...args) => {
+  log(...args);
+  logged += args.map((e) => `${e}`).join(" ") + "\n";
+};
+
+function resetLogCapture() {
+  logged = "";
+}
+
+async function loadProgram(js) {
+  const url = new URL(import.meta.url);
+  url.pathname = "";
+  url.hash = "";
+  url.search = "";
+  const href = url.toString();
+  const js1 = js.replaceAll(
+    /from\s+"\.\/(.+)"/g,
+    `from "${href}precompiled/$1"`,
+  );
+  const js2 = btoa(unescape(encodeURIComponent(js1)));
+  const module = await import("data:text/javascript;base64," + js2);
+  return module.main;
+}
+
+async function compileEval(code) {
+  const result = {
+    log: null,
+    error: null,
+    warnings: [],
+  };
+
+  try {
+    project.writeModule("main", code);
+    project.compilePackage("javascript");
+    const js = project.readCompiledJavaScript("main");
+    const main = await loadProgram(js);
+    resetLogCapture();
+    if (main) main();
+  } catch (error) {
+    console.error(error);
+    result.error = error.toString();
+  }
+  for (const warning of project.takeWarnings()) {
+    result.warnings.push(warning);
+  }
+  result.log = logged;
+
+  return result;
+}
+
+self.onmessage = async (event) => {
+  const result = compileEval(event.data);
+  postMessage(await result);
+};