lazy-fortran · krystophny · Aug 4, 2025 · Aug 4, 2025 · Aug 4, 2025
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+# Action Plan: Making fluff the "Ruff of Fortran"
+
+## Vision
+
+Transform fluff from its current prototype state (10-15% complete) into a production-ready, blazing-fast Fortran linter and formatter that rivals ruff's impact on Python development.
+
+## Core Principles (from Ruff)
+
+1. **⚡ Speed**: 10-100x faster than existing tools
+2. **🎯 Zero Configuration**: Works out of the box
+3. **🔧 Fix Everything**: Automatic fixes for all violations
+4. **📦 Drop-in Replacement**: Compatible with existing workflows
+5. **🌐 Universal**: Support all Fortran standards + Lazy Fortran
+
+## Critical Path to Success
+
+### Week 1-2: Foundation Emergency Surgery
+
+#### Day 1-3: Test Infrastructure Revival
+```fortran
+! Current: No tests run
+! Target: 100% test execution with coverage
+```
+- [ ] Add test-drive as dependency
+- [ ] Convert all 86 test files to test-drive format
+- [ ] Create test runner script
+- [ ] Add coverage reporting
+- [ ] Set up CI to run tests on every commit
+
+#### Day 4-7: fortfront Integration Completion
+```fortran
+! Current: AST parsed but not traversable
+! Target: Full AST manipulation capability
+```
+- [ ] Implement `ast_traverse` using fortfront's visitor pattern
+- [ ] Implement `ast_get_node_type` with full node type detection
+- [ ] Implement `ast_get_children` for AST navigation
+- [ ] Implement `ast_get_node_location` for precise error reporting
+- [ ] Create comprehensive AST utility functions
+
+#### Day 8-10: Configuration System
+```fortran
+! Current: TOML parsing stubbed
+! Target: Full configuration with defaults
+```
+- [ ] Integrate TOML-Fortran library
+- [ ] Implement configuration loading
+- [ ] Add configuration validation
+- [ ] Create default configurations for common use cases
+- [ ] Support pyproject.toml style configuration
+
+### Week 3-4: Core Linting Engine
+
+#### Implement High-Value Rules First
+Priority order based on user impact:
+
+1. **F001**: implicit none (✅ already done)
+2. **F006**: unused variables
+3. **F007**: undefined variables  
+4. **F008**: missing intent
+5. **F002**: indentation consistency
+6. **F003**: line length
+7. **F012**: naming conventions
+
+Implementation template for each rule:
+```fortran
+subroutine check_rule_fXXX(ctx, node_index, violations)
+    ! 1. Use fortfront visitor to traverse AST
+    ! 2. Pattern match on node types
+    ! 3. Apply semantic analysis from context
+    ! 4. Generate violations with fix suggestions
+    ! 5. Return actionable diagnostics
+end subroutine
+```
+
+### Week 5-6: Formatter Implementation
+
+#### AST-Preserving Formatter
+```fortran
+! Use fortfront's emit_fortran with custom formatting
+```
+- [ ] Implement style-guide based formatting
+- [ ] Preserve comments and preprocessor directives
+- [ ] Support partial formatting (ranges)
+- [ ] Add format-on-save capability
+- [ ] Ensure idempotent formatting
+
+### Week 7-8: Performance Optimization
+
+#### Target Metrics
+- **Speed**: Process 100K lines in <1 second
+- **Memory**: <100MB for typical projects
+- **Startup**: <50ms cold start
+
+#### Optimization Strategies
+1. **Parallel Processing**: Use OpenMP for file-level parallelism
+2. **Caching**: Implement persistent AST cache
+3. **Incremental Analysis**: Only reanalyze changed files
+4. **Memory Pool**: Reuse allocations
+5. **Profile-Guided Optimization**: Use real-world codebases
+
+### Week 9-10: Developer Experience
+
+#### LSP Server
+- [ ] Implement full LSP protocol
+- [ ] Real-time diagnostics
+- [ ] Code actions for fixes
+- [ ] Hover information
+- [ ] Go to definition
+
+#### IDE Integration
+- [ ] VS Code extension
+- [ ] Neovim plugin
+- [ ] Emacs package
+- [ ] Sublime Text package
+
+### Week 11-12: Ecosystem Integration
+
+#### Build System Support
+- [ ] CMake integration
+- [ ] Meson support
+- [ ] Make integration
+- [ ] fpm native support
+
+#### CI/CD Integration
+- [ ] GitHub Actions
+- [ ] GitLab CI
+- [ ] Jenkins plugin
+- [ ] Pre-commit hooks
+
+### Week 13-14: Advanced Features
+
+#### Performance Rules (P001-P007)
+- [ ] Loop optimization detection
+- [ ] Array access patterns
+- [ ] Memory allocation patterns
+- [ ] Vectorization opportunities
+- [ ] Cache-friendly code detection
+
+#### Lazy Fortran Support
+- [ ] Seamless dialect detection
+- [ ] Automatic conversion
+- [ ] Mixed-dialect projects
+
+### Week 15-16: Production Readiness
+
+#### Quality Assurance
+- [ ] Test on major Fortran projects (stdlib, LAPACK, PETSc)
+- [ ] Performance benchmarks vs competitors
+- [ ] Security audit
+- [ ] Documentation completion
+
+#### Release Engineering
+- [ ] Binary releases for all platforms
+- [ ] Package managers (brew, apt, conda)
+- [ ] Docker images
+- [ ] Automated release pipeline
+
+## Success Metrics
+
+### Performance (Must Match Ruff)
+| Metric | Current | Target | Ruff Equivalent |
+|--------|---------|--------|-----------------|
+| 100K lines processing | N/A | <1s | <0.5s |
+| Startup time | N/A | <50ms | <20ms |
+| Memory usage | N/A | <100MB | <50MB |
+| Incremental analysis | None | <100ms | <50ms |
+
+### Feature Parity Checklist
+- [ ] 50+ built-in rules
+- [ ] Automatic fixing for 90% of violations
+- [ ] Configuration compatibility with existing tools
+- [ ] Watch mode with instant feedback
+- [ ] Editor integration for top 5 editors
+- [ ] CI/CD integration for top 5 platforms
+
+### Adoption Goals
+- [ ] 1,000 GitHub stars in 6 months
+- [ ] 10+ major projects using fluff
+- [ ] 5+ contributors from community
+- [ ] Package manager availability
+
+## Implementation Priority Matrix
+
+| Impact ↓ Effort → | Low | Medium | High |
+|-------------------|-----|--------|------|
+| **High** | Fix tests<br>AST integration | Core rules<br>Formatter | Performance opt |
+| **Medium** | Config system<br>TOML parsing | LSP server<br>Watch mode | IDE plugins |
+| **Low** | Documentation | Advanced rules | Extensibility |
+
+## Risk Mitigation
+
+### Technical Risks
+1. **fortfront API gaps**: ✅ Already resolved - APIs available
+2. **Performance bottlenecks**: Profile early and often
+3. **Memory usage**: Use arena allocators like fortfront
+
+### Adoption Risks
+1. **Legacy code compatibility**: Support Fortran 77 onwards
+2. **Build system variety**: Support all major systems
+3. **Change resistance**: Provide migration guides
+
+## Competitive Analysis
+
+### Current Fortran Linters
+- **fprettify**: Slow, limited rules
+- **FORD**: Documentation only
+- **flint**: Abandoned
+
+### fluff Advantages
+1. **Speed**: 100x faster through AST caching
+2. **Completeness**: Linting + formatting + LSP
+3. **Modern**: Supports latest Fortran standards
+4. **Unique**: Lazy Fortran support
+
+## Call to Action
+
+### Immediate Next Steps (This Week)
+1. Fix test infrastructure - **BLOCKER**
+2. Complete fortfront AST integration - **BLOCKER**
+3. Implement first 5 AST-based rules
+4. Remove all stub implementations
+5. Create benchmark suite
+
+### Community Engagement
+1. Blog post: "Building the Ruff of Fortran"
+2. Conference talk proposal for FortranCon
+3. Reddit/HN launch when MVP ready
+4. YouTube demo videos
+
+## Conclusion
+
+fluff can become the "ruff of Fortran" in 16 weeks with focused execution. The path is clear:
+1. Fix foundations (Weeks 1-2)
+2. Build core features (Weeks 3-8)
+3. Optimize performance (Weeks 9-10)
+4. Polish UX (Weeks 11-14)
+5. Launch (Weeks 15-16)
+
+The Fortran community desperately needs modern tooling. fluff can fill this gap by delivering ruff-level performance and usability to scientific computing.