/// <summary>
/// Count how many occurences of the specified <see cref="string"/> exist within a given <see cref="char"/>[].
/// </summary>
/// <param name="self">The string to look through.</param>
/// <param name="value">The value to look for.</param>
/// <returns>The number of occurrences of the given value in the <see cref="string"/>.</returns>
public static int CountOccurrences(this char[] self, string value)
{
GenericExtensions.ThrowIfNull(self, nameof(self));
GenericExtensions.ThrowIfNull(value, nameof(value));
char[] checkChars = value.ToCharArray();
int length = self.Length;
int checkLength = checkChars.Length;
int count = 0;
int checkCount = 0;
for (int i = length - 1; i >= 0; i--)
{
if (checkCount == checkLength)
{
count++;
checkCount = 0;
}
if (self[i] == checkChars[checkCount])
{
checkCount++;
}
else
{
checkCount = 0;
}
}
return(count);
}
public static async Task <T> InvokeAndRetryAsync <T>(this Func <Task <T> > action, int attempts, TimeSpan retryInterval, IEnumerable <Exception> fatalExceptions = null)
{
GenericExtensions.ThrowIfNull(action, nameof(action));
if (attempts < 1)
{
throw new ArgumentOutOfRangeException(nameof(attempts), "Must make at least one attempt.");
}
int maxAttempts = attempts;
ICollection <Exception> exceptions = new List <Exception>();
while (attempts > 0)
{
try
{
if (attempts < maxAttempts)
{
await Task.Delay(retryInterval);
}
return(await action());
}
catch (Exception ex) when(!fatalExceptions?.Contains(ex) ?? true)
{
exceptions.Add(ex);
}
attempts--;
}
throw new AggregateException(exceptions);
}
public static T InvokeAndRetryIf <T, TExc>(this Func <T> action, int attempts, TimeSpan retryInterval) where TExc : Exception
{
GenericExtensions.ThrowIfNull(action, nameof(action));
if (attempts < 1)
{
throw new ArgumentOutOfRangeException(nameof(attempts), "Must make at least one attempt.");
}
Exception firstExc = null;
while (attempts-- > 0)
{
try
{
return(action());
}
catch (TExc ex)
{
firstExc ??= ex;
Thread.Sleep(retryInterval);
}
}
throw firstExc;
}
/// <summary>
/// Checks if a given <see cref="string"/> is a numeric value.
/// </summary>
/// <param name="value">The <see cref="string"/> to parse.</param>
/// <param name="style">The number style to use for parsing.</param>
/// <param name="culture">The culture info to use for parsing.</param>
/// <returns></returns>
/// <remarks>Uses <see cref="double.TryParse(string, NumberStyles, IFormatProvider, out double)"/>.</remarks>
public static bool IsNumeric(this string value, NumberStyles style = NumberStyles.Number, CultureInfo culture = null)
{
GenericExtensions.ThrowIfNull(value, nameof(value));
if (culture is null)
{
culture = CultureInfo.InvariantCulture;
}
return(!string.IsNullOrWhiteSpace(value) && double.TryParse(value, style, culture, out _));
}
public static IEnumerable <T> ReverseEnumerable <T>(this LinkedList <T> list)
{
GenericExtensions.ThrowIfNull(list, nameof(list));
LinkedListNode <T> node = list.Last;
while (node != null)
{
yield return(node.Value);
node = node.Previous;
}
}
/// <summary>
/// Count how many occurences of the specified <see cref="char"/> exist within a given <see cref="char"/>[].
/// </summary>
/// <param name="self">The string to look through.</param>
/// <param name="value">The value to look for.</param>
/// <returns>The number of occurrences of the given value in the <see cref="char"/>[].</returns>
public static int CountOccurrences(this char[] self, char value)
{
GenericExtensions.ThrowIfNull(self, nameof(self));
int length = self.Length;
int count = 0;
for (int i = length - 1; i >= 0; i--)
{
if (self[i] == value)
{
count++;
}
}
return(count);
}
/// <summary>
/// Count how many occurences of the specified <see cref="char"/>s exist within a given <see cref="string"/>.
/// </summary>
/// <param name="self">The string to look through.</param>
/// <param name="value">The value to look for.</param>
/// <returns>The number of occurrences of the given values in the <see cref="string"/>.</returns>
public static int CountOccurrences(this string self, params char[] values)
{
GenericExtensions.ThrowIfNull(self, nameof(self));
return(self.ToCharArray().CountOccurrences(values));
}
