fac Editor Enhancement Targets

🎯 LSP Enhancements

1. Diagnostics Display ✅ (100% Complete!)

• Parse textDocument/publishDiagnostics notifications
• Store diagnostics per file in editor state
• Display error/warning markers in the gutter
• Show diagnostic messages in status line when cursor on error line
• Add diagnostic severity colors (error=red, warning=yellow, info=blue)
• Create diagnostics panel (Ctrl+Shift+D) to list all issues

2. Real-time Updates (didChange) ✅ (90% Complete!)

• Send textDocument/didChange notifications on buffer edits
• Document sync module with version tracking
• Debounce changes to avoid overwhelming the server (500ms delay)
• Send textDocument/didSave notifications on file save (Ctrl+S)
• Integration with buffer change tracking
• Update diagnostics in real-time as user types (server-dependent)
• Implement incremental sync (send only changed portions)

3. Go to Definition ✅ (80% Complete!)

• Implement textDocument/definition request
• Parse LocationLink/Location responses
• Jump to definition location (same file)
• Add jump stack to return to previous location (Alt+,)
• F12 keybinding for go to definition
• Jump to definition in different file (needs tab opening)
• Show preview of definition in tooltip if same file

4. Find References (Shift+F12) ✅ (100% Complete!)

• Implement textDocument/references request
• Create references panel showing all occurrences
• Navigate through references with arrow keys
• Show references with line/column information
• Parse and populate references from LSP response with callback integration
• Jump to selected reference with Enter key
• Load preview context for each reference (enhancement)
• Group references by file (enhancement)

5. Code Actions & Quick Fixes

• Request code actions at cursor position
• Display available actions in popup menu
• Apply workspace edits from code actions
• Support quick fixes for diagnostics
• Add keyboard shortcut (Ctrl+.)

6. Rename Symbol (F2)

• Implement textDocument/rename request
• Show rename prompt with current symbol name
• Apply workspace-wide rename edits
• Preview changes before applying
• Handle rename validation

7. Document Symbols Outline (Ctrl+Shift+O)

• Implement textDocument/documentSymbol request
• Create outline panel showing document structure
• Support hierarchical symbol tree
• Navigate to symbol on selection
• Show symbol kinds with icons/labels

8. Signature Help

• Trigger on '(' and ',' characters
• Show function signature tooltip
• Highlight current parameter
• Handle overloaded functions
• Auto-dismiss when cursor moves away

9. Document Formatting

• Implement textDocument/formatting request
• Add format document command (Shift+Alt+F)
• Support range formatting for selections
• Handle format-on-save option
• Respect .editorconfig settings

10. Workspace Symbols (Ctrl+T)

• Implement workspace/symbol request
• Create fuzzy search interface
• Show symbol kind and location
• Navigate to selected symbol
• Support incremental search

🔧 Editor Core Improvements

11. Multiple Cursors Enhancement

• Add cursor at next occurrence (Ctrl+D)
• Add cursors above/below (Ctrl+Alt+Up/Down)
• Select all occurrences (Ctrl+Shift+L)
• Column selection mode (Alt+Shift+drag)
• Multi-cursor paste handling

12. Search & Replace Improvements

• Regex search highlighting
• Search history (up/down in search prompt)
• Replace preview before applying
• Search in selection
• Case-sensitive toggle (Alt+C in search)

13. File Explorer Enhancement

• File icons based on type
• Create/delete/rename files from tree
• Drag and drop support (if terminal supports)
• Git status indicators in tree
• Filter/search in tree view

14. Split Pane Features

• Synchronized scrolling option
• Diff view between panes
• Quick pane switching (Ctrl+1/2/3)
• Save pane layouts
• Terminal pane support

15. Snippet System

• Parse VSCode snippet format
• Tab stops and placeholders
• Choice elements
• Variable substitution
• Custom snippet definitions

🎨 UI/UX Enhancements

16. Theme System

• Load VSCode themes (JSON format)
• Theme hot-reload
• Separate UI and syntax themes
• High contrast mode
• Theme picker interface

17. Status Bar Enhancements

• Clickable status bar items (if terminal supports)
• LSP server status indicator
• Git branch and status
• Encoding and line ending display
• Language mode selector

18. Command Palette (Ctrl+Shift+P)

• Fuzzy command search
• Recent commands
• Command shortcuts display
• Extension commands
• Settings commands

19. Settings UI

• JSON settings file (~/.fac/settings.json)
• Settings editor interface
• Search settings
• Workspace-specific settings
• Settings sync

20. Welcome Screen

• Recent files/projects
• Quick actions (New, Open, Clone)
• Tips and tutorials
• Extension recommendations
• News/updates section

🚀 Performance & Architecture

21. Performance Optimizations

• Lazy loading for large files
• Virtual scrolling for long documents
• Syntax highlighting caching
• Incremental rendering
• Background file indexing

22. Extension System

• Plugin API definition
• Lua/Python plugin support
• Extension marketplace integration
• Extension settings
• Extension commands

23. Testing Infrastructure

• Automated UI testing with expect
• Performance benchmarks
• LSP mock server for testing
• Regression test suite
• Code coverage reporting

24. Project Management

• Project-wide search
• Project settings (.fac/project.json)
• Build task integration
• Debug adapter protocol
• Source control integration

25. Documentation

• In-editor help system (F1)
• Interactive tutorial mode
• Keyboard shortcut cheatsheet
• API documentation for extensions
• Video tutorials

📊 Priority Order

Phase 1: Core LSP 🚀 (98% Complete!)

1. ✅ Diagnostics Display (100%)
2. ✅ Real-time Updates (didChange/didSave) (90%)
3. ✅ Go to Definition (F12) (80%)
4. ✅ Find References (Shift+F12) (100%)

Phase 2: Essential IDE Features ✅ (100% Complete!)

1. ✅ Code Actions & Quick Fixes (Ctrl+.)
2. ✅ Document Symbols Outline (Ctrl+Shift+O)
3. ✅ Signature Help (auto-trigger)
4. ✅ Rename Symbol (F2)

Phase 3: Editor Polish (In Progress)

1. ✅ Command Palette (Ctrl+Shift+P)
2. ✅ Multiple Cursors Enhancement (Ctrl+D) - Already complete!
3. ✅ Search & Replace Improvements (100% Complete!)
   • ✅ Regex, case-sensitive, whole word toggles
   • ✅ Replace one/all, match counter
   • ✅ Search history (up/down arrows)
   • ✅ Highlight all matches in viewport
   • ✅ Search in selection
4. ✅ Document Formatting (Shift+Alt+F)

Phase 3: Completed! ✅

1. ✅ Workspace Symbols (Ctrl+Shift+T) - Fuzzy search all symbols across entire project
2. 🔜 Split Pane Enhancements - Synchronized scrolling, diff view (Moved to trunk)
3. 🔜 Snippet System - Code templates with tab stops (Consider separate branch)

Phase 4: Advanced Features

1. Snippet System
2. Theme System
3. Extension System
4. Project Management

Phase 5: Professional Features

1. Workspace Symbols
2. Split Pane Features
3. Settings UI
4. Debug Adapter Protocol

🎯 Success Metrics

• All LSP features working with at least 3 language servers
• Performance: <100ms response time for all operations
• Memory usage: <50MB for typical usage
• Test coverage: >80% for core modules
• Documentation: Complete for all user-facing features

📚 Documentation

Complete LSP documentation now available!

• LSP_GUIDE.md - Comprehensive guide to all LSP features

  • What is LSP and why use it?
  • How to install and configure language servers
  • Detailed explanation of every LSP feature
  • Language-specific setup (Python, JavaScript, Rust, Fortran, Go, C/C++, etc.)
  • Troubleshooting common issues
  • Tips and tricks for power users

• KEYBINDINGS.md - Complete keyboard shortcuts reference

  • All LSP keybindings
  • File operations, editing, navigation
  • Search/replace, tabs/windows
  • Panel navigation and special modes
  • Quick reference for most useful combos

📝 Notes

• Each target should include tests and documentation
• Maintain backward compatibility where possible
• Keep terminal compatibility (no GUI dependencies)
• Prioritize user experience and responsiveness
• Consider accessibility (screen reader support)