/// <summary>
/// Exercises the condition method.
/// </summary>
/// <param name="condition">The condition.</param>
/// <returns>IEnumerable<System.String>.</returns>
private IEnumerable <string> EmptyConditionalExecute(ContinueWhile condition)
{
for (var index = Start; condition(index, index.ToString());)
{
yield return(index.ToString());
}
}
protected IEnumerable <string> Shortcut(ContinueWhile condition)
{
if (Settings.Pairs == null || Settings.Pairs.Length == 0)
{
return((condition != null) ? EmptyConditionalExecute(condition) :
Range().Select(s => s.ToString()));
}
return(null);
}
/// <summary>
/// Instead of running through a fore-known range, this method passes the last index
/// and the last value generated so that it will continue to iterate until some formula
/// that may use the last value and/or the last fizz/buzz string generated.
/// </summary>
/// <param name="condition">The condition delegate that accepts last index and last value and
/// returns true if the function should continue, false if it should end now.</param>
/// <returns>IEnumerable System.String.</returns>
private IEnumerable <string> ConditionalExecute(ContinueWhile condition)
{
var index = Settings.Start;
var lastValue = string.Empty;
while (condition(index, lastValue))
{
var pairs = Settings.Pairs.Where(x => (index % x.Key) == 0).Select(kvp => kvp.Value).ToArray();
lastValue = pairs.Any() ? $"{string.Join("", pairs)}" : $"{index}";
index += Increment(index);
yield return(lastValue);
}
}
public IEnumerable <string> ExecuteWhile(ContinueWhile condition, IFizzBuzzSettings fizzBuzzSettings = null)
{
Settings = fizzBuzzSettings;
return(Shortcut() ?? Shortcut(condition) ?? ConditionalExecute(condition));
}
public FizzBuzzWhile(IFizzBuzzSettings settings, ContinueWhile condition) : base(settings)
{
_condition = condition;
}
public FizzBuzzWhile(ContinueWhile condition) : this(null, condition)
{
}
public FibonacciFizzBuzz(IFizzBuzzSettings settings, ContinueWhile condition) : base(settings, condition)
{
}