Here's a super handy extension on Swift's Optional type, which gives us a really nice API for easily unwrapping an optional, or throwing an error in case the value turned out to be nil:

extension Optional {
    func orThrow(_ errorExpression: @autoclosure () -> Error) throws -> Wrapped {
        switch self {
        case .some(let value):
            return value
        case .none:
            throw errorExpression()
        }
    }
}

let file = try loadFile(at: path).orThrow(MissingFileError())

Manning

Enter Manning’s September Showdown — a 30-day challenge that gives developers a chance to test their knowledge against their peers. A new trivia question, and a brand new prize to win, is published every day throughout September.

Check out today’s questionChecking out this sponsor helps support my work. More about ads on this site.