money

Overview ¶

Package money provides precise decimal-based money handling for financial applications.

This package uses the shopspring/decimal library to avoid floating-point precision issues common in financial calculations. It supports the Mauritanian Ouguiya (MRU) currency and provides convenient methods for money operations.

Usage ¶

import (
	"github.com/CatoSystems/rim-pay/pkg/money"
	"github.com/shopspring/decimal"
)

// Create money amounts
amount1 := money.New(decimal.NewFromInt(10050), "MRU")  // 100.50 MRU
amount2 := money.FromFloat64(75.25, "MRU")              // 75.25 MRU

// Arithmetic operations
sum := amount1.Add(amount2)         // 175.75 MRU
diff := amount1.Subtract(amount2)   // 25.25 MRU

// Formatting and conversion
fmt.Println(amount1.String())       // "100.50 MRU"
fmt.Println(amount1.Cents())        // 10050 (amount in minor units)
fmt.Println(amount1.Amount())       // 100.50 (decimal amount)

Currency Support ¶

Currently supports:

• MRU: Mauritanian Ouguiya (current since January 1, 2018; 1 MRU = 100 cents)

Note: The old MRO currency was replaced by MRU on January 1, 2018, at a rate of 10 MRO = 1 MRU.

Precision ¶

All calculations use decimal arithmetic to maintain precision:

• No floating-point rounding errors
• Exact decimal representation
• Safe for financial calculations

Validation ¶

Money amounts are validated to ensure:

• Positive values only
• Valid currency codes
• Proper decimal precision (2 decimal places for MRU)

Thread Safety ¶

Money instances are immutable and thread-safe. All operations return new Money instances rather than modifying existing ones.