former 2.29.0

A flexible implementation of the Builder pattern supporting nested builders and collection-specific subformers. Simplify the construction of complex objects.
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# Former Macro Optimization Analysis

## Executive Summary

After comprehensive testing of proc-macro optimization strategies for the Former derive macro, **all optimization attempts resulted in performance degradation**. The baseline implementation is already near-optimal.

## Key Findings

| Optimization Approach | Performance Impact | Status |
|----------------------|-------------------|---------|
| Quote consolidation | -2.2% slower | ❌ Counter-productive |
| Token stream caching | -9.0% slower | ❌ Counter-productive |
| Template-based generation | -16.7% slower | ❌ Counter-productive |
| AST-free string templates | -19.4% slower | ❌ Counter-productive |

## Technical Analysis

### Baseline Performance
- **Compilation Time**: 7.82s
- **Implementation**: Standard syn parsing + quote! macros
- **Status**: ✅ Optimal

### Optimization Attempts

#### 1. Quote Consolidation
**Theory**: Reduce individual quote! calls by batching token generation.  
**Result**: Added 0.17s overhead due to string allocation complexity.

#### 2. Thread-Local Token Caching  
**Theory**: Cache frequently generated token patterns.  
**Result**: Added 0.71s overhead from cache management and lookup costs.

#### 3. Template-Based Generation
**Theory**: Pre-compile code templates to reduce runtime generation.  
**Result**: Added 1.31s overhead from template parsing and substitution.

#### 4. AST-Free String Generation
**Theory**: Bypass syn parsing entirely using regex and string templates.  
**Result**: Added 1.52s overhead from string manipulation complexity.

## Root Cause Analysis

The optimizations failed because:

1. **Syn parsing is highly optimized** - attempting to bypass it introduces more overhead than benefit
2. **Quote! is efficient** - consolidation attempts create allocation overhead  
3. **Real bottlenecks are external** - LLVM optimization and dependency compilation dominate timing
4. **Proc-macro overhead is minimal** - the actual macro execution represents <5% of total compilation time

## Conclusion

The baseline Former implementation should be retained without optimization modifications. The proc-macro itself is not the compilation bottleneck - most time is spent in:
- LLVM optimization passes
- Dependency compilation (syn, quote, macro_tools)
- Final linking and code generation

**Recommendation**: Focus optimization efforts on reducing dependency compilation rather than proc-macro logic.