directions.md

Add more HepMC3 functionality like: Particle creation and manipulation Vertex handling Event construction

Now that we have the basic functionality working (FourVectors, Particles, Vertices, and Events), we can move on to implementing more advanced features.

1. Add Cross-section calculations:

   • Implement GenCrossSection functionality
   • Add methods for setting and getting cross-section values
   • Add uncertainty handling

2. Add PDF Information:

   • Implement GenPdfInfo functionality
   • Add methods for parton information
   • Handle PDF sets and scales

3. Add Heavy Ion functionality:

   • Implement GenHeavyIon
   • Add methods for heavy ion specific properties
   • Handle collision parameters

4. Add Event manipulation methods:

   • Event traversal (getting all particles, vertices)
   • Finding particles by PDG ID
   • Event statistics

Which feature would you like to implement next? We can continue with the same pattern of:

1. Adding C++ wrapper functions
2. Implementing Julia interface
3. Writing comprehensive tests

Looking at your test suite and comparing it with HepMC3's functionality, you have implemented most of the core features. Let's analyze what you have and what might be missing:

Implemented Features:

1. ✅ Basic Event Structure

   • Event creation and manipulation
   • Vertex handling
   • Particle creation and properties

2. ✅ Physics Properties

   • Four-vectors and momentum
   • PDG IDs and status codes
   • Cross-sections
   • PDF information

3. ✅ Heavy Ion Physics

   • All basic heavy ion properties
   • Centrality
   • Event plane angles
   • Eccentricities

4. ✅ Event Manipulation

   • Particle/vertex traversal
   • Parent/child relationships
   • Event validity checks
   • Momentum conservation

5. ✅ Event Units and Conversions

   • Unit conversion methods
   • Explicit unit handling tests

6. ✅ Event Attributes

   • Generic attribute handling
   • Custom attribute support

7. Event I/O

• Reading/writing events to files
• Different format support (HepMC3 ASCII, ROOT, etc.)

8. Run Information

   • GenRunInfo handling
   • Weight handling
   • Run-level attributes

9. Memory Management

   • Explicit cleanup methods
   • Resource management tests

10. Error Handling

• More comprehensive error cases
• Invalid state handling

To make it production-ready, I would suggest:

1. Add Documentation:

   """
   # HepMC3.jl
   
   Julia wrapper for the HepMC3 event record library.
   
   ## Features
   - Complete event record functionality
   - Particle and vertex manipulation
   - Heavy ion physics support
   - PDF and cross-section handling
   - Event traversal and analysis
   
   ## Example
   ```julia
   using HepMC3
   
   # Create an event
   evt = GenEvent()
   
   # Create particles
   p1 = GenParticle(FourVector(0.0, 0.0, 10.0, 10.0), 11, 1)
   p2 = GenParticle(FourVector(0.0, 0.0, -10.0, 10.0), -11, 1)
   
   # Create vertex
   v = GenVertex()
   add_particle_in!(v, p1)
   add_particle_out!(v, p2)
   
   # Add to event
   add_vertex!(evt, v)

   """

2. Add CI/CD:

   • GitHub Actions for automated testing
   • Coverage reporting
   • Documentation generation

3. Add Examples:

   • Common physics processes
   • Integration with other packages
   • Performance benchmarks

4. Add Version Compatibility:

   • Explicit version requirements
   • Compatibility with different HepMC3 versions

Would you like me to help you implement any of these additional features before pushing to production? Also, it would be good to:

1. Clean up duplicate test cases (you have some repeated tests)
2. Organize tests into logical groups
3. Add more edge cases and error handling tests

Let me know which aspects you'd like to focus on first!