Praxly2

Praxly is an educational programming environment designed to bridge the gap between pseudocode and standard programming languages. It allows users to write code in one language (Python, Java, Praxis, or CSP) and instantly:

• Translate it into another supported language
• Visualize the Abstract Syntax Tree (AST)
• Execute the code entirely within the browser

Praxly2 is a modern TypeScript rewrite of Praxly featuring a robust compiler architecture with lexical analysis, parsing, interpretation, and code generation—all running securely in the browser with no backend required.

Features

• Universal AST: All languages parse to the same intermediate representation
• Multi-language support: Python, Java, CSP (pseudocode), and Praxis
• Real-time translation: See code translated live as you type
• Code execution: Run programs directly in the browser
• AST visualization: Explore how your code is structured
• Modern editor: Built with CodeMirror for syntax highlighting and accessibility

Quick Start

Install dependencies:

npm install

Start the development server:

npm run dev

Then open your browser to the URL provided (typically http://localhost:5173/v2/).

Running Tests

Unit tests primarily for compiler and AST:

npm run test
npm run test:run

Integration tests using headless selenium:

npm run test-browser
npm run test-browser -- --test "Print once"
npm run test-browser -- --from-index 120

Quality checks:

npm run prettier:check
npm run lint-staged:check

Common npm Scripts

Use these commands during normal development:

npm run dev                # Start Vite dev server
npm run build              # Type-check and production build
npm run test               # Run Vitest in watch mode
npm run test:run           # Run Vitest once
npm run test-browser       # Run Selenium CSV suite (headless)
npm run test-browser:headed # Run Selenium suite in visible Chrome
npm run prettier:check     # Check formatting
npm run prettier:write     # Rewrite files with Prettier
npm run lint-staged:check  # Validate lint-staged config

Browser test script examples:

npm run test-browser -- --help
npm run test-browser -- --test "Print once"
npm run test-browser -- --from-index 120
npm run test-browser -- --filter "Array" --no-fail-fast

Documentation

For a detailed architectural overview and onboarding guide, see docs/README.md.

Contributing

See CONTRIBUTING.md for setup steps, quality checks, and pull request guidelines.

License

Praxly2's source code is available under CC BY-NC-SA 4.0. See LICENSE for details.