DoCatch-markup-guard.swift

//New Feature on Swift2 doCatch-guard-markup

//: # Swift2 Features - do-Catch

import Darwin

//: Do-Catch type errors
enum DoCatchError : ErrorType {
    case DifferentValuesError
}

//: Declare 3 constants
//: * cols
//: * rows
//: * total -> should be cols * rows

let cols = 10
let rows = 10
let total = 100

//: This function check if total is cols * rows, if don't launch a error.
func validateParameters() throws -> Bool{
//New Feature again - guard
    guard total == cols*rows else {
        throw DoCatchError.DifferentValuesError
    }
    return true
}

//: ## Do-catch Example
do {
//launch try for the exception
    try validateParameters()
    print("OK buddy")
}catch DoCatchError.DifferentValuesError {
    fatalError("\(cols) * \(rows) != \(total)")
}