try?.swift

//: Playground - noun: a place where people can play

import Foundation

enum PersonError: ErrorProtocol {
    case doesNotExistInDataSource
    case emailNotInPersonalData
}

struct Person {
    let name: String
    let age: Int
    private(set) var emailAddress: String?
    
    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }
    
    mutating func setEmailAddress(from dataSource: [String : AnyObject]) throws {
        guard let personData = dataSource[name] as? [String : AnyObject] else {
            throw PersonError.doesNotExistInDataSource
        }
        
        guard let emailAddress = personData["email"] as? String else {
            throw PersonError.emailNotInPersonalData
        }
        
        self.emailAddress = emailAddress
    }
}

let ted = Person(name: "Ted", age: 24)
let sarah = Person(name: "Sarah", age: 42)
let brad = Person(name: "Brad", age: 38)
let julie = Person(name: "Julie", age: 20)

let VIPs = [ted, sarah]
let others = [brad, julie]

let contactInfo = [
    "Ted": ["email": "ted@ted.me"],
    "Sarah": ["telephone": "05556789555"],
    "Brad": ["email": "brad@hotmail.com"]
]

var all = [Person]()

// VIPs must have an email address
for var importantPerson in VIPs {
    do {
        try importantPerson.setEmailAddress(from: contactInfo)
        all.append(importantPerson)
    } catch let personError as PersonError {
        switch personError {
        case .doesNotExistInDataSource:
            print("Error: Supplied data does not contain \(importantPerson.name)'s data")
        case .emailNotInPersonalData:
            print("Error: \(importantPerson.name)'s data does not contain an email address")
        }
    }
}

// For non-VIPs, the email address is optional
for var person in others {
    try? person.setEmailAddress(from: contactInfo)
    all.append(person)
}

print("=======")
for person in all {
    print(person)
}