Decimal is a Go library for arbitrary-precision fixed-point decimal numbers.
The library solves the problem of representing decimal values exactly in financial and monetary calculations, where binary floating-point types like float64 introduce rounding errors that accumulate over time. It uses a fixed-point approach where numbers are stored with a specified precision, ensuring that string representations match the actual values precisely. This makes it particularly suitable for money handling, where every fraction of a unit must be accounted for and rounding behavior is predictable.
Developers should choose this library when building financial systems, e-commerce platforms, or any application requiring exact decimal arithmetic without precision loss. The tool is well-suited for scenarios involving addition, subtraction, and multiplication where no precision is sacrificed, as well as division with explicitly specified precision. The README acknowledges that other libraries may be better suited for different use cases: those prioritizing performance with lower precision requirements might prefer alternatives, while applications needing mutable APIs similar to big.Int or specialized billing features may find other options more appropriate.
The project maintains a straightforward, stable implementation focused on core decimal operations. It provides serialization support for databases, JSON, and XML, making it practical for real-world applications. The library's zero-value is safely initialized to 0, reducing initialization boilerplate. Development appears measured and deliberate, with the maintainers explicitly acknowledging the existence of alternative libraries and encouraging users to evaluate options based on their specific needs rather than promoting this as a universal solution.
