Analyzes field storage patterns and recommends ElementSet approach:
- Element has NO field type parameter (simpler type)
- ElementSet groups elements + shared fields
- Fields can be NamedTuple, struct, any type-stable container
- Embraces immutability (GPU-compatible, thread-safe)
- Separates mutable state from immutable parameters
Design rationale:
- Benchmarks show NamedTuple gives 9-92× speedup vs Dict
- Immutability enables GPU execution without copying
- Creating new containers ~1000× faster than deepcopy
- Matches physical reality (material properties per set)
Compares three options:
1. Fields as type parameter (type proliferation)
2. ElementSet pattern (RECOMMENDED)
3. Hybrid approach (too complex)
Addresses common concerns:
- Time-dependent fields (use interpolation)
- Material state (separate mutable arrays)
- Custom field types (any type-stable container works)
Status: Ready for implementation
Jukka Aho