None(), OneOf(), Many(), XOf()
Count-based extensions which make checking the length of something more readable. * Updated on 2010-01-16 following suggestion from @Sane regarding the use of Count() in None(). Switched to Any(). Thanks!
Source
public static class LinqExtensions
{
public static bool None<T>(this IEnumerable<T> source)
{
return source.Any() == false;
}
public static bool None<T>(this IEnumerable<T> source, Func<T, bool> query)
{
return source.Any(query) == false;
}
public static bool Many<T>(this IEnumerable<T> source)
{
return source.Count() > 1;
}
public static bool Many<T>(this IEnumerable<T> source, Func<T, bool> query)
{
return source.Count(query) > 1;
}
public static bool OneOf<T>(this IEnumerable<T> source)
{
return source.Count() == 1;
}
public static bool OneOf<T>(this IEnumerable<T> source, Func<T, bool> query)
{
return source.Count(query) == 1;
}
public static bool XOf<T>(this IEnumerable<T> source, int count)
{
return source.Count() == count;
}
public static bool XOf<T>(this IEnumerable<T> source, Func<T, bool> query, int count)
{
return source.Count(query) == count;
}
}
Example
List<string> myList = new List<string>() { "foo", "bar", "fong", "foo" };
//returns false
myList.None();
//returns false
myList.None(x=> x == "bar");
//returns true
myList.None(x=> x == "bang");
//returns true
myList.Many();
//returns true
myList.Many(x=> x == "foo");
//returns false
myList.Many(x=> x == "bar");
//returns false
myList.OneOf();
//returns false
myList.OneOf(x=> x == "foo");
//returns true
myList.OneOf(x=> x == "bar");
//returns true
myList.Xof(4);
//returns true
myList.XOf(x=> x == "foo", 2);
//returns false
myList.XOf(x=> x == "foo", 3);
Author: Dan Atkinson
Submitted on: 9 jan. 2010
Language: C#
Type: System.Collections.Generic.IEnumerable<T>
Views: 5964