Add LaTeX sargam letter properties for better visualization rendering

[jon-myers]

Summary

Implements LaTeX-compatible sargam letter properties to resolve rendering issues with Unicode diacritics in visualization libraries like matplotlib.

New Properties Added

• latex_sargam_letter - LaTeX-compatible base sargam letter (same as sargam_letter)
• latex_octaved_sargam_letter - LaTeX math mode with properly positioned diacritics
• _octave_latex_diacritic() - Helper method for LaTeX octave notation

Problem Solved

Unicode combining diacritics (e.g., Ṡ, Ṙ, Ġ) often render poorly in matplotlib:

• Dots above uppercase letters are barely visible or overlap
• Font-dependent rendering inconsistencies
• Horizontal positioning issues in some contexts

Solution Benefits

• Perfect rendering in matplotlib and other LaTeX-compatible libraries
• Consistent cross-platform appearance regardless of system font
• Backward compatibility - all existing properties remain unchanged
• Easy adoption - simply use latex_octaved_sargam_letter instead of octaved_sargam_letter

Usage Examples

pitch = Pitch({'swara': 'sa', 'oct': 1})

# Before (problematic in matplotlib):
pitch.octaved_sargam_letter  # Returns "Ṡ" - renders poorly

# After (clean LaTeX):
pitch.latex_octaved_sargam_letter  # Returns "$\dot{\mathrm{S}}$" - renders perfectly

Test Plan

• ✅ All existing tests continue to pass (backward compatibility verified)
• ✅ Added 8 comprehensive test functions covering:
  • All sargam letters (S, R, G, M, P, D, N) in raised/lowered forms
  • All octave levels (-3 to +3)
  • Edge cases with log_offset and custom fundamentals
  • Serialization/deserialization
  • Helper method functionality

🤖 Generated with Claude Code

[jon-myers]

@claude review

[claude]

Claude encountered an error —— View job

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Code Review for LaTeX Sargam Properties

Reviewing the implementation of LaTeX-compatible sargam letter properties...

Todo List:

• Read and analyze pitch.py changes
• Read and analyze test file changes
• Review code quality and implementation patterns
• Check test coverage and quality
• Verify backward compatibility
• Provide comprehensive review feedback

Review Analysis

Implementation Quality ✅

Positive aspects:

1. Clean, focused addition - Only adds what's needed without modifying existing code
2. Consistent naming - Follows established property naming conventions (latex_sargam_letter, latex_octaved_sargam_letter)
3. Proper separation of concerns - LaTeX logic isolated in dedicated helper method _octave_latex_diacritic()
4. Good documentation - Clear docstrings explaining the purpose of each property

Code quality observations:

• Implementation in pitch.py:294-360 is clean and well-structured
• Helper method correctly maps octaves to LaTeX math commands
• Logic appropriately handles edge cases (no octave marking returns plain letter)
• LaTeX math mode wrapping is correctly implemented with $...$ syntax

Test Coverage ✅

Excellent test coverage with 8 comprehensive test functions:

1. test_latex_sargam_letter_basic() - Validates basic functionality matches existing sargam_letter
2. test_latex_octaved_sargam_letter_no_octave() - Edge case for oct=0
3. test_latex_octaved_sargam_letter_positive_octaves() - All positive octave levels
4. test_latex_octaved_sargam_letter_negative_octaves() - All negative octave levels
5. test_latex_octaved_sargam_letter_all_sargam_all_octaves() - Comprehensive matrix testing
6. test_latex_properties_preserve_backward_compatibility() - Regression protection
7. test_latex_octave_diacritic_helper() - Helper method validation
8. test_latex_properties_edge_cases() - Complex scenarios with log_offset, different fundamentals

Test quality: Tests are thorough, well-documented, and cover both happy path and edge cases.

Backward Compatibility ✅

Perfect backward compatibility maintained:

• All existing properties unchanged
• No modifications to existing methods
• New properties are purely additive
• Serialization (to_json()/from_json()) unaffected

Technical Implementation Review

LaTeX Command Choices - Good selection:

• \dot{}, \ddot{}, \dddot{} for dots above (standard LaTeX)
• \underset{\bullet}{} etc. for dots below (appropriate for subscript positioning)
• \mathrm{} wrapper ensures consistent roman font

Logic Flow (pitch.py:350-360):

def latex_octaved_sargam_letter(self) -> str:
    base_letter = self.sargam_letter
    latex_diacritic = self._octave_latex_diacritic()
    
    if not latex_diacritic:
        return base_letter  # No octave marking
    elif latex_diacritic.startswith(r'\underset'):
        return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'
    else:
        return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'

Minor Observation: Lines 358-360 have identical logic - could be simplified to:

if not latex_diacritic:
    return base_letter
else:
    return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'

Problem Solving Assessment ✅

The PR addresses a real matplotlib rendering issue:

• Unicode combining diacritics (Ṡ, Ṙ, Ġ) render poorly in matplotlib
• LaTeX math mode provides consistent cross-platform rendering
• Solution is targeted and doesn't break existing workflows

Recommendation: APPROVE ✅

This is a well-implemented, thoroughly tested feature that solves a legitimate visualization problem without breaking existing functionality. The code follows project conventions and includes comprehensive test coverage.

Suggested minor improvement: Consider simplifying the conditional logic in latex_octaved_sargam_letter as noted above, though this is not blocking.

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[claude]

Claude finished @jon-myers's task —— View job

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PR Review: LaTeX Sargam Letter Properties

Review Checklist

• Read and analyze the pitch.py implementation changes
• Review the test coverage in pitch_test.py
• Check code quality and best practices
• Identify potential bugs or issues
• Evaluate performance considerations
• Assess security concerns
• Provide comprehensive feedback

Code Quality Assessment: ✅ Excellent

🎯 Summary

This PR elegantly solves Unicode diacritic rendering issues in matplotlib by adding LaTeX-compatible sargam letter properties. The implementation is clean, well-tested, and maintains perfect backward compatibility.

✅ Strengths

Implementation Quality:

• Clean architecture: New properties follow existing patterns (latex_sargam_letter, latex_octaved_sargam_letter)
• Proper encapsulation: Helper method _octave_latex_diacritic() centralizes LaTeX mapping logic
• Consistent naming: Follows established snake_case conventions

Problem-Solution Fit:

• Addresses real issue: Unicode combining diacritics (Ṡ, Ṙ, Ġ) render poorly in matplotlib
• Elegant solution: LaTeX math mode ensures consistent cross-platform rendering
• Practical approach: Simple property swap (octaved_sargam_letter → latex_octaved_sargam_letter)

Backward Compatibility:

• Zero breaking changes: All existing properties/behavior preserved
• Additive-only: No modifications to existing logic
• Clean interface: New properties complement existing ones

🔍 Code Analysis

idtap/classes/pitch.py:294-361

def _octave_latex_diacritic(self) -> str:
    """Convert octave to LaTeX math notation for proper diacritic positioning."""
    mapping = {
        -3: r'\underset{\bullet\bullet\bullet}',  # Triple dot below  
        -2: r'\underset{\bullet\bullet}',         # Double dot below
        -1: r'\underset{\bullet}',                # Single dot below
        1: r'\dot',                               # Single dot above
        2: r'\ddot',                              # Double dot above  
        3: r'\dddot'                              # Triple dot above
    }
    return mapping.get(self.oct, '')

Analysis: Excellent mapping design with clear LaTeX commands for both above/below diacritics.

Lines 350-361

@property  
def latex_octaved_sargam_letter(self) -> str:
    """LaTeX math mode sargam letter with properly positioned diacritics."""
    base_letter = self.sargam_letter
    latex_diacritic = self._octave_latex_diacritic()
    
    if not latex_diacritic:
        return base_letter  # No octave marking
    elif latex_diacritic.startswith(r'\underset'):
        return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'
    else:
        return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'

Analysis: Proper LaTeX formatting with \mathrm{} for upright text and correct escaping.

🧪 Test Coverage Assessment: ✅ Outstanding

Comprehensive Test Suite (188+ new lines):

• 8 dedicated test functions covering all edge cases
• All sargam letters (S, R, G, M, P, D, N) in raised/lowered forms
• All octave levels (-3 to +3) with correct LaTeX output
• Edge cases: log_offset, custom fundamentals, serialization
• Backward compatibility verification

Example test verification:

def test_latex_octaved_sargam_letter_positive_octaves():
    p = Pitch({'swara': 'sa', 'oct': 1})
    assert p.latex_octaved_sargam_letter == r'$\dot{\mathrm{S}}$'

🚀 Performance: ✅ Excellent

• O(1) operations: Simple dictionary lookups and string formatting
• Lazy evaluation: Properties computed on-demand
• No memory overhead: No additional instance variables
• Minimal computational cost: String concatenation only

🔒 Security: ✅ Safe

• No user input processing: Internal property generation only
• Safe string operations: No eval/exec or dangerous operations
• Proper escaping: LaTeX strings correctly formatted
• No external dependencies: Uses standard Python string formatting

🐛 Potential Issues: ✅ None Found

• No logical errors or bugs identified
• Exception handling inherited from existing methods
• Edge cases properly covered in tests
• Type hints consistent and appropriate

📋 Minor Observations

1. Code duplication in latex_octaved_sargam_letter (lines 357-360):

   elif latex_diacritic.startswith(r'\underset'):
       return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'
   else:
       return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'

   Both branches return identical formatting. Could be simplified to:

   return f'${latex_diacritic}{{\\mathrm{{{base_letter}}}}}$'

2. Documentation could mention matplotlib explicitly in docstrings for better discoverability.

🎉 Recommendation: ✅ APPROVE

This is a high-quality implementation that:

• Solves a real-world rendering problem elegantly
• Maintains perfect backward compatibility
• Includes comprehensive test coverage
• Follows established code patterns
• Has zero security or performance concerns

The minor code duplication doesn't impact functionality and the PR provides significant value for matplotlib users dealing with Unicode diacritic rendering issues.

--- • Branch: issue-19-latex-sargam-properties