// These extensions allow a list of strings to be joined together
/// <summary>
/// Joins all strings together into a single string, separating each item with the separator.
/// <para>For example: </para> <c>alphabet.JoinStrings(", ") == "a, b, ... y, z"</c>
/// </summary>
/// <param name="source">The source of strings to join together</param>
/// <param name="separator">The text to insert between items</param>
public static string JoinStrings(this IEnumerable <string> source, string separator)
{
ArgumentValidator.CheckForNullReference(source, "source");
return(string.Join(separator, source as string[] ?? source.ToArray()));
}
/// <summary>Splits the enumeration into segments,
/// each segment containing the portion between predicate matches.
/// </summary>
/// <param name="source"></param>
/// <param name="splitPredicate">The condition that will create a new split.
/// The matching item will be the last element in the previous split.
/// This predicate incorporates the element's index.
/// </param>
public static IEnumerable <TSource[]> SplitAfter <TSource>(this IEnumerable <TSource> source, Func <TSource, int, bool> splitPredicate)
{
ArgumentValidator.CheckForNullReference(source, "source");
ArgumentValidator.CheckForNullReference(splitPredicate, "splitPredicate");
return(SplitIterator(source, null, splitPredicate, true));
}
/// <summary>Uses String.Format to format each item in the collection using the specified format.</summary>
/// <param name="source"></param>
/// <param name="format">
/// A composite format string; same as String.Format.
/// {0} refers to the source object, {1} refers to the index.
/// </param>
public static IEnumerable <string> FormatEach <T>(this IEnumerable <T> source, string format)
{
ArgumentValidator.CheckForNullReference(source, "source");
ArgumentValidator.CheckForNullReference(format, "format");
return(source.Select((arg, index) => string.Format(format, new object[] { arg, index })));
}
/// <summary>Splits the enumeration into segments,
/// each segment containing [count] items, and the last segment containing the remainder.
/// </summary>
/// <param name="source"></param>
/// <param name="count">The number of items to include in each segment.
/// The last segment might contain fewer items.</param>
public static IEnumerable <TSource[]> Split <TSource>(this IEnumerable <TSource> source, int count)
{
ArgumentValidator.CheckForNullReference(source, "source");
ArgumentValidator.CheckForZeroValue(count, "count");
return(SplitIterator(source, count));
}
/// <summary>Chooses one of the items at random.
///
/// Returns default if there are no items.
/// </summary>
public static T RandomOrDefault <T>(this IEnumerable <T> source)
{
ArgumentValidator.CheckForNullReference(source, "source");
return(RandomIterator(source));
}
/// <summary>Chooses one of the items at random.
///
/// Throws an exception if there are no items.
/// </summary>
public static T Random <T>(this IEnumerable <T> source)
{
ArgumentValidator.CheckForEmpty(source, "source");
return(RandomIterator(source));
}