Money

A Library to represent Money for Swift 5.

Features:

• Strongly Typed
• Lightweight

Considerations:

• Some values lose precision when initialized from a float literal

Installation

• Swift Package Manager

Usage

You can create your own Currency by writing a struct or final class that conforms to the Currency protocol:

struct USD: Currency {
    static var code: String = "USD"
    static var minorUnits: Int? = 2
    var value: Decimal
    
    init(_ value: Decimal) {
        self.value = value
    }
}

You can also copy the currencies you need from the Currencies target. Creating your own currencies is a good idea if you only need some of them, however, if you need all the currencies from the ISO 4217 you can import the Currencies Library which contains a struct for every currency in the specification:

import Currencies

let price: USD = 200
let cost: MXN = "200"
let amount = EUR(200)

Comparing

You can only compare money of the same currency

USD(60) > USD(20) // true
TND(10) <= TND(20) // true

USD(10) == JPY(10) // Compilation error: Cannot convert value of type 'JPY' to expected argument type 'USD'

Arithmetic

Money types can be added, subtracted, multiplied and divided:

let subtotal = GBP(300) + GBP(40)
let price = EUR(200) - EUR(20)
let tax = CAD(100) / 10
let value = JPY(400) * 2

let prices: [USD] = ["12.39", "36.47", "27.19"]
let total = prices.sum()