RPAL Language Interpreter

A comprehensive interpreter for the RPAL programming language, featuring lexical analysis, syntax parsing, AST/ST visualization, and semantic evaluation.

Developed by Team Atlantis 🌊

📋 Table of Contents

• Overview
• Features
• Prerequisites
• Installation
• Usage
• Project Structure
• Build Methods
• Examples
• Contributing
• License

🔍 Overview

This RPAL interpreter is a complete implementation that processes RPAL (Right-reference Pedagogical Algorithmic Language) source code through multiple phases:

• Lexical Analysis - Tokenizes the input source code
• Syntax Parsing - Builds Abstract Syntax Trees (AST)
• Tree Standardization - Converts AST to Standardized Trees (ST)
• Semantic Evaluation - Executes the program and produces results

✨ Features

• 🔧 Modular Architecture - Clean separation of lexer, parser, and evaluator components
• 🌳 Tree Visualization - Optional AST and ST output for debugging and learning
• 🚀 Multiple Build Options - Support for both Maven and Makefile builds
• 📊 Comprehensive Testing - Includes test cases for validation
• 🎯 Standards Compliant - Full RPAL language specification support

📋 Prerequisites

• Java JDK 8+ (tested with Java 21)
• Maven 3.6+ (for Maven build method)
• Make utility (for Makefile build method)

🚀 Installation

Method 1: Maven Build (Recommended)

# Clone the repository
git clone <repository-url>
cd rpal-lang-interpreter

# Clean and build the project
mvn clean install

This creates a JAR file in the target/ directory.

Method 2: Makefile Build

# Navigate to source directory
cd rpal/src/main/java

# Compile using make
make

This generates .class files in the same directory structure.

🎮 Usage

Basic Execution

java myrpal <input_file>

With Output Redirection

java myrpal test/test1 > output.txt

Debug Options

Use optional switches to visualize internal tree structures:

Switch	Description
-ast	Print Abstract Syntax Tree
-st	Print Standardized Tree

Examples

# Run basic interpretation
java myrpal test/test1

# View AST structure
java myrpal -ast test/test1

# View both AST and ST
java myrpal -ast -st test/test1

# Save output to file
java myrpal -ast test/test1 > debug_output.txt

📁 Project Structure

rpal-lang-interpreter/
├── src/
│   └── main/
│       └── java/
│           ├── lexer/          # Lexical analysis components
│           ├── parser/         # Syntax parsing and AST generation
│           ├── evaluator/      # Semantic evaluation engine
│           └── myrpal.java     # Main entry point
├── test/                       # Test cases and examples
├── target/                     # Maven build output
├── pom.xml                     # Maven configuration
├── Makefile                    # Alternative build configuration
└── README.md                   # This file

🔨 Build Methods

Maven (Preferred)

Maven provides dependency management, testing integration, and packaging:

# Clean previous builds
mvn clean

# Compile and package
mvn compile package

# Run tests
mvn test

# Complete build with tests
mvn clean install

Makefile (Alternative)

For environments where Maven isn't available or for submission requirements:

cd rpal/src/main/java
make clean  # Remove previous .class files
make        # Compile all source files

📝 Examples

Sample RPAL Program

let add x y = x + y
in add 5 3

Running the Example

# Assuming the above code is saved as 'sample.rpal'
java myrpal sample.rpal
# Output: 8

# View the AST structure
java myrpal -ast sample.rpal

🧪 Testing

The project includes comprehensive test cases in the test/ directory:

# Run all test cases using Makefile
make test

🤝 Contributing

We welcome contributions! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

This project is developed as part of an academic assignment. Please respect academic integrity guidelines when using this code.

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🆘 Troubleshooting

Common Issues

Java version compatibility: Ensure you're using JDK 8 or higher

java -version

Maven not found: Install Maven or use the Makefile alternative

mvn --version

Class not found errors: Ensure you're running from the correct directory after building

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Made by Team Atlantis

Building bridges between theory and practice, one parse tree at a time.