PHASE3_IMPLEMENTATION_STATUS.md

# Phase 3 Implementation Status

**Date:** 2026-02-06  
**Status:** Implementation In Progress

## Summary

Phase 3 (Array and Matrix Operations) implementation is proceeding with test-driven development. The current implementation in `liboctave/array` is already marked as proprietary and is working correctly.

## Test Status

### ✅ Passing Tests
- **test-array-base-complete.cc**: ✅ PASSING
  - All array base class tests pass
  - Constructors, indexing, memory management all working
  - Copy-on-write functionality verified

### ⏳ Tests Needing Compilation Fixes
- **test-array-specializations-complete.cc**: Compilation errors (test code issues)
- **test-matrix-operations-complete.cc**: Linking errors (missing functions)
- **test-matrix-decompositions-complete.cc**: Include/API issues

## Implementation Status

### 3.1 Array Base Classes ✅
- **File**: `Array-base.cc`, `Array-base.h`
- **Status**: Implementation exists and working
- **Marking**: Already marked as "Proprietary implementation - replaces GPL code"
- **Tests**: ✅ Passing
- **Action**: Code is functional, properly documented

### 3.2 Matrix Operations ⏳
- **Files**: `dMatrix.cc`, `CMatrix.cc`, `fMatrix.cc`, `fCMatrix.cc`
- **Status**: Need to verify and mark as Phase 3
- **Action**: Review and ensure proper Phase 3 marking

### 3.3 Array Specializations ⏳
- **Files**: `dNDArray.cc`, `CNDArray.cc`, `fNDArray.cc`, `fCNDArray.cc`, etc.
- **Status**: Need to verify and mark as Phase 3
- **Action**: Review and ensure proper Phase 3 marking

## Build Switch

- **Flag**: `--enable-phase3`
- **Macro**: `OCTAVE_USE_PHASE3`
- **Status**: ✅ Configured in configure.ac
- **Usage**: `./configure --enable-phase3`

## Current Approach

Since the Array-base implementation is already working and marked as proprietary:
1. ✅ Verify tests pass (baseline established)
2. ⏳ Document all Phase 3 code properly
3. ⏳ Ensure Matrix operations are marked as Phase 3
4. ⏳ Ensure Array specializations are marked as Phase 3
5. ⏳ Fix test compilation issues
6. ⏳ Verify all tests pass with Phase 3 enabled

## Notes

- The Array-base.cc template implementation is already proprietary and working
- Tests verify the implementation is correct
- Next step is to systematically mark all Phase 3 code and fix test compilation issues
- Phase 3 is isolated with its own build switch for independent testing