rekenmodule

A rekenmodule is a software component that encapsulates calculation logic used by other parts of a system. It provides a well-defined API for performing mathematical, financial, or unit-conversion operations while keeping the rest of the software decoupled from implementation details.

A typical rekenmodule offers core functionality such as basic arithmetic, financial calculations (interest, depreciation, taxes), currency handling, unit conversions, and rounding and precision control. It also handles input validation and error reporting, and may support more advanced functions or domain-specific rules depending on the context. The module is designed to be reusable and testable, so other components can rely on its behavior without duplicating logic.

Design considerations include the choice of numeric types to ensure accuracy, especially for monetary calculations. Decimal or fixed-point representations are preferred over floating point to avoid rounding errors. Deterministic results, immutability, a clear and stable API, and thread-safety are common goals. Localization and currency awareness may be required for user-facing or internationalized applications. Comprehensive testing, explicit error handling, and well-documented contracts are important for long-term maintenance and interoperability.

Architecturally, a rekenmodule can be a library or a standalone service. It is often implemented with patterns that support extensibility, such as strategy or plugin architectures, to swap calculation rules or support domain-specific behavior. Versioning of its API or contracts helps maintain compatibility with dependent components.

Common use cases include accounting and invoicing software, payroll systems, e-commerce pricing engines, and engineering or scientific applications that require reliable, centralized calculation logic. Implementations commonly employ language-specific decimal types (for example, Java BigDecimal, Python Decimal, or C# decimal) and clear rounding modes.