Lumacs/documentation/history/PHASE2_COMPLETE.md

Phase 2: Buffer Management - COMPLETE! ✅

Overview

Phase 2 implementation is complete! Lumacs now supports full buffer management, allowing you to work with multiple files effectively. The editor has jumped from ~55% to ~70% Emacs compatibility.

What Was Implemented

1. Buffer Switching (C-x b) ⭐⭐⭐

Efficiently switch between open buffers.

• Command: C-x b (switch-to-buffer)
• Features:
  • Minibuffer prompt
  • Tab Completion: Cycle through available buffer names
  • Auto-activates major mode for the switched buffer
  • Displays progress (e.g., [1/3]) when cycling

2. Buffer List (C-x C-b) ⭐⭐⭐

View and manage all open buffers.

• Command: C-x C-b (list-buffers)
• Features:
  • Opens a read-only *Buffer List* buffer
  • Shows: Modification status (*), Buffer Name, Size (lines), and File Path
  • Formatted in columns for readability
  • Refreshes content on every invocation

3. Safe Buffer Killing (C-x k) ⭐⭐⭐

Close buffers safely.

• Command: C-x k (kill-buffer)
• Features:
  • Minibuffer prompt with tab completion
  • Safety Check: Warns if the buffer is modified (Buffer modified! Kill anyway? (y/n))
  • Prevents closing the last buffer (keeps at least one open)
  • Automatically switches windows displaying the killed buffer to another buffer

Architecture Changes

C++ Core (src/, include/lumacs/)

• Buffer Class: Added clear() method to efficiently empty a buffer (exposed to Lua).
• EditorCore:
  • Added get_buffer_names(), get_buffer_by_name(), switch_buffer_in_window(), close_buffer(), get_all_buffer_info().
  • Implemented logic to handle buffer closing safety.
• NcursesEditor (src/main_ncurses.cpp):
  • Added input modes: BufferSwitch, KillBuffer, ConfirmKill.
  • Implemented generic tab completion logic for minibuffer.
  • Added visual feedback for modes in status line.

Lua Configuration (init.lua)

• Bound C-x b, C-x k, C-x C-b to new functionality.
• Implemented C-x C-b formatting logic in Lua using get_all_buffer_info and Buffer:clear().

Testing

Manual Verification:

1. Switch Buffer: Open multiple files (./build/lumacs file1 file2). Use C-x b to switch. Press Tab to cycle.
2. List Buffers: Press C-x C-b. Check the *Buffer List* content. Modify a buffer and check for * marker.
3. Kill Buffer:
   • Kill an unmodified buffer (C-x k -> Name -> Enter). It should close immediately.
   • Modify a buffer. Try to kill it. Check for warning prompt (y/n).
   • Press n: Cancelled.
   • Press y: Buffer closed.

Unit Tests:

• Added Buffer_Clear test to tests/test_buffer.cpp to verify Buffer::clear() functionality.

Keybinding Summary

Key	Command	Description
C-x b	switch-to-buffer	Switch to another buffer (Tab completion)
C-x C-b	list-buffers	List all open buffers
C-x k	kill-buffer	Close current or specified buffer

Emacs Compatibility Progress

Before Phase 2: ~55/100 After Phase 2: ~70/100 ✅

We now have: ✅ Working Minibuffer with completion ✅ Multiple buffer management ✅ Safety mechanisms (modified check) ✅ Buffer list visualization

What's Next: Phase 3

Phase 3 focuses on Enhanced Editing:

1. Word operations (M-d, M-DEL, M-t)
2. Case conversion (M-u, M-l, M-c)
3. Comment/Uncomment (M-;)
4. Incremental Search (C-s, C-r)