ICollectionExtensions

Extension methods for System.Collections.Generic.ICollection<T> that add readability-oriented collection queries.

Definition

Namespace: Paragon Assembly: Paragon.dll

public static class ICollectionExtensions

Remarks

This is a readability helper that avoids the double-negative pattern of !collection.Contains(item). It works with any ICollection<T> implementation including List<T>, HashSet<T>, arrays, and Dictionary<TKey, TValue>.Keys.

Methods

NotContains

Returns true if the collection does not contain the specified item. Syntactic inverse of ICollection<T>.Contains().

public static bool NotContains<T>(this ICollection<T> collection, T item)

Parameter	Type	Description
collection	ICollection<T>	The collection to search
item	T	The item to check for

Returns: true if the item is not in the collection; false if it is.

Examples

using System.Collections.Generic;
using Paragon;

var visited = new HashSet<int> { 1, 2, 3 };

// Instead of: if (!visited.Contains(4))
if (visited.NotContains(4))
{
    visited.Add(4);
}

See Also

• IEnumerableExtensions — LINQ-style utilities for IEnumerable<T>

• Extensions — extension system overview