//Check if the password is long enough
    func isPasswordLongEnough(_ password:String) -> Validation<[String], String> {
        if password.characters.count < 8 {
            return Validation.Failure(["Password must have more than 8 characters."])
        } else {
            return Validation.Success(password)
        }
    }

    //Check if the password contains a special character
    func isPasswordStrongEnough(_ password:String) -> Validation<[String], String> {
        if (password.range(of:"[\\W]", options: .regularExpression) != nil){
            return Validation.Success(password)
        } else {
            return Validation.Failure(["Password must contain a special character."])
        }
    }

    //Check if the user is different from password, by Jlopez
    func isDifferentUserPass(_ user:String, _ password:String) -> Validation<[String], String> {
        if (user == password){
            return Validation.Failure(["Username and password MUST be different."])
        } else {
            return Validation.Success(password)
        }
    }


    //Concating all validations in one that checks all rules
    func isPasswordValid(user: String, password:String) -> Validation<[String], String> {
        return isPasswordLongEnough(password)
            .sconcat(isPasswordStrongEnough(password))
            .sconcat(isDifferentUserPass(user, password))
    }


    //Examples with invalid password
    let result = isPasswordValid(user: "Richi", password: "Richi")
    /* ▿ Validation<Array<String>, String>
           ▿ Failure : 3 elements
                - 0 : "Password must have more than 8 characters."
                - 1 : "Password must contain a special character."
                - 2 : "Username and password MUST be different."
    */

    //Example with valid password
    let result = isPasswordValid(user:"Richi", password: "Ricardo$")
    /*
       ▿ Validation<Array<String>, String>
           - Success : "Ricardo$"
    */