FastRegex

A high-performance regular expression library for Python with JIT compilation and SIMD optimizations.

🚀 Features

• JIT Compilation: LLVM-based just-in-time compilation for complex patterns
• SIMD Optimizations: AVX2/AVX512/SSE4.2/NEON support for vectorized operations
• Smart Caching: Automatic caching of compiled patterns to avoid recompilation
• Python Integration: Seamless integration via pybind11
• High Performance: 1.5-5x faster than standard re module for specific use cases

📊 Performance Benchmarks

Test Case	Python re (ms)	FastRegex (ms)	Speedup
Short literals	0.0040	0.0023	1.7x ✅
Simple patterns	0.0041	0.0025	1.6x ✅
Find all matches	0.0127	0.0095	1.3x ✅
Match operations	0.0040	0.0023	1.7x ✅

Key insights:

• 1.5-1.9x faster for most use cases
• Best performance on short literals and simple patterns
• Fully compatible with standard re module behavior
• Optimized for patterns < 50 characters

🛠 Installation

From PyPI (Recommended)

Using Docker (Recommended)

# Clone the repository
git clone https://github.com/baksvell/fastregex.git
cd fastregex

# Run with Docker
docker-compose up -d fastregex

# Enter the container
docker exec -it fastregex-dev bash

# Use FastRegex
python -c "import fastregex; print('FastRegex ready!')"

From PyPI

pip install fastregex

From Source

git clone https://github.com/baksvell/fastregex.git
cd fastregex
pip install -e .

Prerequisites

• CMake 3.20+
• Python 3.10+
• C++17 compiler (GCC/MSVC/Clang)

📖 Usage

Basic Usage

import fastregex

# Simple search
result = fastregex.search(r'\d+', 'abc123def')
print(result)  # True

# Find all matches
matches = fastregex.find_all(r'\w+', 'hello world test')
print(matches)  # ['hello', 'world', 'test']

# Replace
new_text = fastregex.replace(r'\d+', 'abc123def456', 'XXX')
print(new_text)  # 'abcXXXdefXXX'

# Compile for reuse
compiled = fastregex.compile(r'\d+')
result = compiled.search('abc123def')
print(result)  # True

Advanced Features

# Check cache statistics
print(f"Cache size: {fastregex.cache_size()}")
print(f"Hit rate: {fastregex.hit_rate():.2%}")

# Pattern information
compiled = fastregex.compile(r'\d+')
print(f"Pattern: {compiled.pattern()}")
print(f"JIT compiled: {compiled.jit_compiled}")

🎯 When to Use FastRegex

✅ Use FastRegex when:

• Short literal patterns (1.7x faster)
• Simple regex patterns (1.6x faster)
• Match operations (1.7x faster)
• Find all operations (1.3x faster)
• Patterns < 50 characters

⚠️ Use standard re when:

• Very large texts (>10MB)
• Complex regex patterns with many groups
• Need advanced regex features
• Long patterns (>50 characters)

🔄 Hybrid approach:

import re
import fastregex as fr

def smart_match(pattern, text):
    if len(pattern) > 15 and len(text) > 1000:
        return fr.search(pattern, text)
    return re.search(pattern, text)

🧪 Testing

Run the test suite:

python -m pytest tests/

Run performance benchmarks:

python tests/benchmark.py

📚 API Reference

Core Functions

• fastregex.match(pattern, text) - Match from start of string
• fastregex.search(pattern, text) - Search anywhere in string
• fastregex.find_all(pattern, text) - Find all matches
• fastregex.replace(pattern, text, replacement) - Replace matches
• fastregex.compile(pattern) - Compile pattern for reuse

Cache Management

• fastregex.cache_size() - Get current cache size
• fastregex.hit_rate() - Get cache hit rate
• fastregex.clear_cache() - Clear the cache

Pattern Information

• compiled.pattern() - Get the compiled pattern
• compiled.jit_compiled - Check if pattern is JIT compiled
• compiled.compile_time() - Get compilation time

🤝 Contributing

Contributions are welcome! Please see CONTRIBUTING.md for details.

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests
5. Submit a pull request

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🔗 Links

• GitHub Repository
• Documentation
• Issue Tracker

🙏 Acknowledgments

• pybind11 for Python bindings
• LLVM for JIT compilation
• SIMD for vectorized operations