# Changelog
All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
## [1.0.1] - 2025-07-22
### Changed
- Fix links with incorrect URLs
## [1.0.0] - 2025-07-21
### Added
- Initial project setup with comprehensive development tooling
- Complete test suite with 14 test cases covering edge cases and typical scenarios
- Full documentation with examples and use cases
- Performance optimization with O(log n) time complexity
- Type specifications for better development experience
- **Core Functionality**: `TrailingZeros.of/1` function for counting trailing zeros
- **Algorithm Implementation**: Efficient bit manipulation approach using `Bitwise` operations
- **Performance Optimization**: O(log n) time complexity with O(1) space complexity
- **Type Safety**: Full type specifications with `@spec` annotations
- **Comprehensive Testing**: 14 test cases covering:
- Edge cases (0, maximum 32-bit integer)
- Powers of 2 (2^0 through 2^30)
- Odd numbers and mixed patterns
- Large numbers and boundary conditions
- Alternating bit patterns and specific structures
### Changed
- Enhanced project configuration with modern Elixir development practices
- Improved code quality checks with comprehensive tooling
- Updated documentation structure for better maintainability
### Features
- **High Performance**: Optimized bitwise operations for maximum efficiency
- **Memory Efficient**: Tail-recursive implementation with constant space usage
- **Mathematical Accuracy**: Correct handling of all edge cases and mathematical properties
- **Developer Friendly**: Clear documentation with extensive examples
### Documentation
- **Module Documentation**: Comprehensive `@moduledoc` with algorithm explanation
- **Function Documentation**: Detailed `@doc` with parameters, returns, and examples
- **Performance Analysis**: Time and space complexity documentation
- **Use Cases**: Practical examples for power of 2 detection, binary analysis, and memory alignment
- **Mathematical Properties**: Theoretical background and relationships
### Development Tooling
- **Code Quality**: Credo static analysis with custom configuration
- **Type Checking**: Dialyzer integration for type safety
- **Documentation**: ExDoc setup for generated documentation
- **Spell Checking**: Spellweaver integration for documentation quality
- **Formatting**: Consistent code formatting with migration support
- **Dependency Management**: Comprehensive dependency audit and version locking
### Project Structure
- **License**: Apache 2.0 license with University of Kitakyushu copyright
- **README**: Comprehensive documentation with installation, usage, and development instructions
- **Package Configuration**: Proper Hex.pm metadata and GitHub integration
- **Version Management**: Semantic versioning with proper changelog structure
### Technical Implementation
- **Base Case**: Proper handling of input 0
- **Recursive Algorithm**: Efficient bitwise AND and right shift operations
- **Accumulator Pattern**: Tail-recursive implementation for optimal performance
- **Bitwise Operations**: Uses `Bitwise.band/2` and `Bitwise.bsr/2` for efficiency
- **Termination Guarantee**: Algorithm guaranteed to terminate as number decreases with each shift
### Mathematical Properties Supported
- For any number n, if `TrailingZeros.of(n) = k`, then n is divisible by 2^k
- Powers of 2 have trailing zero counts equal to their exponent
- Odd numbers always have 0 trailing zeros
- Maximum trailing zeros for 32-bit integer is 31 (for 0)
### Performance Characteristics
- **Time Complexity**: O(log n) - proportional to number of bits in input
- **Space Complexity**: O(1) - constant space usage with tail recursion
- **Bitwise Efficiency**: Optimized use of bitwise operations
- **Memory Usage**: Minimal memory footprint with no additional data structures
### Use Cases Demonstrated
- **Power of 2 Detection**: Numbers with n trailing zeros are divisible by 2^n
- **Binary Number Analysis**: Understanding structure of binary representations
- **Memory Alignment**: Important for data structure alignment requirements
- **Algorithm Optimization**: Useful in divide-and-conquer algorithms
---
## Version History Summary
### Major Versions
- **v1.0.0**: First stable release with complete functionality
### Development Phases
1. **Project Initialization**: Basic Elixir application structure
2. **Core Implementation**: Trailing zeros algorithm with bitwise operations
3. **Testing & Quality**: Comprehensive test suite and code quality tools
4. **Documentation**: Complete documentation with examples and use cases
5. **Release Preparation**: Package configuration and deployment readiness
### Key Milestones
- ✅ Core algorithm implementation
- ✅ Comprehensive test coverage
- ✅ Complete documentation
- ✅ Development tooling integration
- ✅ Performance optimization
- ✅ Type safety implementation
- ✅ Package configuration
- ✅ Release preparation
---
## Contributing to Changelog
When adding entries to this changelog, please follow these guidelines:
1. **Use the existing format** and structure
2. **Group changes** by type (Added, Changed, Fixed, etc.)
3. **Be descriptive** but concise
4. **Include version numbers** and dates for releases
5. **Follow semantic versioning** for version numbers
6. **Update both Unreleased and version-specific sections** as needed
## Links
- [GitHub Repository](https://github.com/zacky1972/trailing_zeros)
- [Hex Package](https://hex.pm/packages/trailing_zeros)
- [Documentation](https://hexdocs.pm/trailing_zeros)
- [Issues](https://github.com/zacky1972/trailing_zeros/issues)
