ethdebug · gnidan · Jan 15, 2026 · Jan 15, 2026
diff --git a/bin/start b/bin/start
@@ -10,10 +10,11 @@ else
 fi
 
 # Run the commands with concurrently
-concurrently --names=format,pointers,bugc,web,tests \
+concurrently --names=format,pointers,bugc,playground,web,tests \
   "cd ./packages/format && yarn watch" \
   "cd ./packages/pointers && yarn watch" \
   "cd ./packages/bugc && yarn watch" \
+  "cd ./packages/playground && yarn watch" \
   "cd ./packages/web && yarn start $DOCUSAURUS_NO_OPEN" \
   "sleep 5 && yarn test --ui --watch --coverage $VITEST_NO_OPEN"
 
diff --git a/packages/playground/.eslintrc.cjs b/packages/playground/.eslintrc.cjs
@@ -0,0 +1,22 @@
+module.exports = {
+  root: true,
+  env: { browser: true, es2020: true },
+  extends: [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/recommended",
+    "plugin:react-hooks/recommended",
+  ],
+  ignorePatterns: ["dist", ".eslintrc.cjs"],
+  parser: "@typescript-eslint/parser",
+  plugins: ["react-refresh"],
+  rules: {
+    "react-refresh/only-export-components": [
+      "warn",
+      { allowConstantExport: true },
+    ],
+    "@typescript-eslint/no-explicit-any": "error",
+    "@typescript-eslint/explicit-function-return-type": "off",
+    "@typescript-eslint/explicit-module-boundary-types": "off",
+    "no-console": "off",
+  },
+};
diff --git a/packages/playground/.gitignore b/packages/playground/.gitignore
@@ -0,0 +1 @@
+app.bundle.js
diff --git a/packages/playground/README.md b/packages/playground/README.md
@@ -0,0 +1,56 @@
+# @ethdebug/bug-playground
+
+A web-based playground for the BUG language, built with React, TypeScript, and Vite.
+
+## Features
+
+- **Monaco Editor**: Full-featured code editor with BUG syntax highlighting
+- **Live Compilation**: See AST, IR (optimized and unoptimized), and bytecode output
+- **Optimization Levels**: Choose from 4 optimization levels (0-3)
+- **Example Programs**: Automatically loaded from the `examples/` directory
+- **Error Highlighting**: Clear error messages and warnings from the compiler
+
+## Development
+
+Install dependencies:
+
+```bash
+yarn install
+```
+
+Start the development server:
+
+```bash
+yarn dev
+```
+
+Build for production:
+
+```bash
+yarn build
+```
+
+## Scripts
+
+- `yarn start` - Start development server
+- `yarn build` - Build for production
+- `yarn preview` - Preview production build
+- `yarn typecheck` - Run TypeScript type checking
+- `yarn lint` - Run ESLint
+
+## Architecture
+
+The playground is organized by domain/logical concerns:
+
+- `playground/` - Main playground UI and example programs
+- `editor/` - Monaco editor integration and BUG language definition
+- `compiler/` - Compiler integration and output visualization
+- `visualization/` - AST, IR, and bytecode visualizations
+
+## Technologies
+
+- React 18
+- TypeScript 5
+- Vite 5
+- Monaco Editor
+- @ethdebug/bugc (BUG Compiler)
diff --git a/packages/playground/index.html b/packages/playground/index.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>BUG Playground</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
+</html>
diff --git a/packages/playground/package.json b/packages/playground/package.json
@@ -0,0 +1,39 @@
+{
+  "name": "@ethdebug/bug-playground",
+  "version": "0.1.0-0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "start": "vite",
+    "build": "tsc && vite build",
+    "watch": "vite build --watch",
+    "preview": "vite preview",
+    "typecheck": "tsc --noEmit",
+    "lint": "eslint . --ext .ts,.tsx",
+    "format": "prettier --write \"src/**/*.{ts,tsx}\"",
+    "format:check": "prettier --check \"src/**/*.{ts,tsx}\""
+  },
+  "dependencies": {
+    "@ethdebug/bugc": "^0.1.0-0",
+    "@monaco-editor/react": "^4.6.0",
+    "@types/dagre": "^0.7.52",
+    "dagre": "^0.8.5",
+    "monaco-editor": "^0.52.2",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-flow-renderer": "^10.3.17",
+    "vis-network": "^9.1.9"
+  },
+  "devDependencies": {
+    "@types/react": "^18.2.43",
+    "@types/react-dom": "^18.2.17",
+    "@typescript-eslint/eslint-plugin": "^6.14.0",
+    "@typescript-eslint/parser": "^6.14.0",
+    "@vitejs/plugin-react": "^4.2.1",
+    "eslint": "^8.55.0",
+    "eslint-plugin-react-hooks": "^4.6.0",
+    "eslint-plugin-react-refresh": "^0.4.5",
+    "typescript": "^5.2.2",
+    "vite": "^5.0.8"
+  }
+}
diff --git a/packages/playground/src/App.tsx b/packages/playground/src/App.tsx
@@ -0,0 +1,9 @@
+import { Playground } from "./playground/Playground";
+
+export function App() {
+  return (
+    <div className="app">
+      <Playground />
+    </div>
+  );
+}
diff --git a/packages/playground/src/compiler/CompilerOutput.css b/packages/playground/src/compiler/CompilerOutput.css
@@ -0,0 +1,70 @@
+.compiler-output {
+  display: flex;
+  flex-direction: column;
+  height: 100%;
+  background-color: #1e1e1e;
+}
+
+.output-tabs {
+  display: flex;
+  background-color: #2d2d30;
+  border-bottom: 1px solid #3e3e42;
+  overflow-x: auto;
+}
+
+.output-tab {
+  padding: 0.5rem 1rem;
+  background: none;
+  border: none;
+  border-bottom: 2px solid transparent;
+  color: #969696;
+  font-size: 0.875rem;
+  cursor: pointer;
+  white-space: nowrap;
+  transition:
+    color 0.2s,
+    border-color 0.2s;
+}
+
+.output-tab:hover:not(:disabled) {
+  color: #cccccc;
+}
+
+.output-tab.active {
+  color: #ffffff;
+  border-bottom-color: #0e639c;
+}
+
+.output-tab:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
+.output-content {
+  flex: 1;
+  overflow: auto;
+  padding: 1rem;
+}
+
+.output-warnings {
+  background-color: #332b00;
+  border-top: 1px solid #665500;
+  padding: 1rem;
+  color: #ffcc00;
+}
+
+.output-warnings h3 {
+  margin: 0 0 0.5rem 0;
+  font-size: 0.875rem;
+  font-weight: 600;
+}
+
+.output-warnings ul {
+  margin: 0;
+  padding-left: 1.5rem;
+}
+
+.output-warnings li {
+  font-size: 0.813rem;
+  line-height: 1.5;
+}
diff --git a/packages/playground/src/compiler/CompilerOutput.tsx b/packages/playground/src/compiler/CompilerOutput.tsx
@@ -0,0 +1,75 @@
+import { useState } from "react";
+import type { CompileResult } from "./types";
+import { AstView } from "../visualization/AstView";
+import { IrView } from "../visualization/IrView";
+import { CfgView } from "../visualization/CfgView";
+import { BytecodeView } from "../visualization/BytecodeView";
+import { ErrorView } from "./ErrorView";
+import type { SourceRange } from "../visualization/debugUtils";
+import "./CompilerOutput.css";
+
+interface CompilerOutputProps {
+  result: CompileResult;
+  onOpcodeHover?: (ranges: SourceRange[]) => void;
+}
+
+type TabType = "ast" | "ir" | "cfg" | "bytecode" | "error";
+
+export function CompilerOutput({ result, onOpcodeHover }: CompilerOutputProps) {
+  const [activeTab, setActiveTab] = useState<TabType>(
+    result.success ? "ast" : "error",
+  );
+
+  if (!result.success) {
+    return <ErrorView error={result.error} warnings={result.warnings} />;
+  }
+
+  const tabs: { id: TabType; label: string; disabled?: boolean }[] = [
+    { id: "ast", label: "AST" },
+    { id: "ir", label: "IR" },
+    { id: "cfg", label: "CFG" },
+    { id: "bytecode", label: "Bytecode" },
+  ];
+
+  return (
+    <div className="compiler-output">
+      <div className="output-tabs">
+        {tabs.map((tab) => (
+          <button
+            key={tab.id}
+            className={`output-tab ${activeTab === tab.id ? "active" : ""}`}
+            onClick={() => setActiveTab(tab.id)}
+            disabled={tab.disabled}
+          >
+            {tab.label}
+          </button>
+        ))}
+      </div>
+
+      <div className="output-content">
+        {activeTab === "ast" && <AstView ast={result.ast} />}
+        {activeTab === "ir" && (
+          <IrView ir={result.ir} onOpcodeHover={onOpcodeHover} />
+        )}
+        {activeTab === "cfg" && <CfgView ir={result.ir} />}
+        {activeTab === "bytecode" && (
+          <BytecodeView
+            bytecode={result.bytecode}
+            onOpcodeHover={onOpcodeHover}
+          />
+        )}
+      </div>
+
+      {result.warnings.length > 0 && (
+        <div className="output-warnings">
+          <h3>Warnings:</h3>
+          <ul>
+            {result.warnings.map((warning, i) => (
+              <li key={i}>{warning}</li>
+            ))}
+          </ul>
+        </div>
+      )}
+    </div>
+  );
+}
diff --git a/packages/playground/src/compiler/ErrorView.css b/packages/playground/src/compiler/ErrorView.css
@@ -0,0 +1,51 @@
+.error-view {
+  padding: 1rem;
+  height: 100%;
+  overflow: auto;
+}
+
+.error-content {
+  background-color: #5a1d1d;
+  border: 1px solid #f48771;
+  border-radius: 4px;
+  padding: 1rem;
+  margin-bottom: 1rem;
+}
+
+.error-content h3 {
+  color: #f48771;
+  margin: 0 0 0.5rem 0;
+  font-size: 1rem;
+}
+
+.error-message {
+  color: #ffcccc;
+  margin: 0;
+  font-family: "Consolas", "Monaco", "Courier New", monospace;
+  font-size: 0.875rem;
+  line-height: 1.5;
+  white-space: pre-wrap;
+}
+
+.error-warnings {
+  background-color: #332b00;
+  border: 1px solid #665500;
+  border-radius: 4px;
+  padding: 1rem;
+  color: #ffcc00;
+}
+
+.error-warnings h4 {
+  margin: 0 0 0.5rem 0;
+  font-size: 0.875rem;
+}
+
+.error-warnings ul {
+  margin: 0;
+  padding-left: 1.5rem;
+}
+
+.error-warnings li {
+  font-size: 0.813rem;
+  line-height: 1.5;
+}
diff --git a/packages/playground/src/compiler/ErrorView.tsx b/packages/playground/src/compiler/ErrorView.tsx
@@ -0,0 +1,28 @@
+import "./ErrorView.css";
+
+interface ErrorViewProps {
+  error: string;
+  warnings?: string[];
+}
+
+export function ErrorView({ error, warnings }: ErrorViewProps) {
+  return (
+    <div className="error-view">
+      <div className="error-content">
+        <h3>Compilation Error</h3>
+        <pre className="error-message">{error}</pre>
+      </div>
+
+      {warnings && warnings.length > 0 && (
+        <div className="error-warnings">
+          <h4>Warnings:</h4>
+          <ul>
+            {warnings.map((warning, i) => (
+              <li key={i}>{warning}</li>
+            ))}
+          </ul>
+        </div>
+      )}
+    </div>
+  );
+}