Is there an equivalent of "None()" in LINQ?

Question

I've been running into situations where I feel I'm lacking a LINQ extension method which effectivelly checks if there is no match of the specified predicate in a collection. There is Any and All, but if I for instance use the following code:

if (Objects.All(u => u.Distance <= 0))

This returns true if all the objects in the collection are 0 or less yards away.

if (Objects.Any(u => u.Distance <= 0))

This returns true if there is at least one object in the collection which is 0 or less yards away from me.

So far so good, both those methods make sense and the syntax for them makes sense too. Now, if I want to check if there is no object with 0 or less distance, I'd have to invert the predicate inside the All method to >= 0 instead of <= 0 or call !All(), which in some cases results in very poorly readable code.

Is there no method which effectively does Collection.None(u => u.Distance <= 0) to check if there is no object in the collection which is 0 or less yards away? It's syntactic sugar more than an actual problem, but I just have the feeling it's missing.

Answer 1

None is the same as !Any, so you could define your own extension method as follows:

public static class EnumerableExtensions {     public static bool None<TSource>(this IEnumerable<TSource> source,                                      Func<TSource, bool> predicate)     {         return !source.Any(predicate);     } } 

Answer 2

You can write your own Extension Method:

public static bool None(this IEnumerable<T> collection, Func<T, bool> predicate) {   return collection.All(p=>predicate(p)==false); } 

Or on IQueryable<T> as well

public static bool None(this IQueryable<T> collection, Expression<Func<TSource, bool>> predicate) {   return collection.All(p=> predicate(p)==false); }