Utilities for doing currency conversion with the Money library.

This functionality is discussed in Chapter 3 of Flight School Guide to Swift Numbers.

• Swift 4.0+

Add the CurrencyConverter package to your target dependencies in Package.swift:

import PackageDescription

let package = Package(
  name: "YourProject",
  dependencies: [
    .package(
        url: "https://github.com/Flight-School/CurrencyConverter",
        from: "1.0.0"
    ),
  ]
)

Then run the swift build command to build your project.

To use CurrencyConverter in your Xcode project using Carthage, specify it in Cartfile:

github "Flight-School/CurrencyConverter" ~> 1.0.0

Then run the carthage update command to build the framework, and drag the built CurrencyConverter.framework into your Xcode project.

A currency pair describes the relative value of one currency in terms of another. You can create a CurrencyPair object with a specified exchange rate to convert from a monetary amount in one currency to the other:

let EURtoUSD = CurrencyPair<EUR, USD>(rate: 1.17) // as of June 1st, 2018

let euros: Money<EUR> = 123.45
let dollars = EURtoUSD.convert(euros).rounded // "$144.44"

Note: This library doesn't include functionality for querying the current exchange rates of currencies. You can get this information from various third party web applications.

To only allow conversion in one direction, create a type that conforms to the UnidirectionalCurrencyConverter protocol. If you want to offer different rates depending on the direction of conversion (that is, a rate going from variable to fixed that isn't the inverse of going the other way) create a type that conforms to the BidirectionalCurrencyConverter protocol.

MIT

Mattt (@mattt)