CollectionExtensions

Extensions to collections or enumerables in the System.Collections Namespace.

Namespace SUELIB.CollectionExtensions

Dependencies

• System
• System.Collections.Concurrent
• System.Collections.Generic
• System.Linq

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AddDistinct<T>

Adds an item to an ICollection<T> if the item does not already exist in the collection.

Returns true it the object was added successfully.

Parameter	Description
T	The Type contained in the collection.
collection	The collection to be modified.
item	The Object to be added to the collection.

Method

public static bool AddDistinct<T>(this ICollection<T> collection, T item)
{
    bool added = false;
    if (!collection.Contains(item)) { collection.Add(item); added = true; }
    return added;
}

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AddRangeDistinct<T>

Adds an object only if the object does not already exist in the collection.

Returns an int representing the number of items successfully added to the collection.

Parameter	Description
T	The Type of object contained within the collection.
collection	The collection to be modified.
range	The range of Objects to be added to the collection.

Method

public static int AddRangeDistinct<T>(this ICollection<T> collection, ICollection<T> range) where T : class
{
    if (collection is null || range is null) { return 0; }
    int itemsAdded = 0;
    foreach (T item in range)
    {
        if (!collection.Contains(item)) { collection.Add(item); itemsAdded++; }
    }
    return itemsAdded;
}

---

AddRange<T>

Adds a group of objects the collection.

Returns an int representing the number of items successfully added to the collection.

Parameter	Description
T	The Type of object contained within the collection.
collection	The ConcurrentBag<T> to be modified.
range	The range of Objects to be added to the collection.

Method

public static int AddRange<T>(this ConcurrentBag<T> collection, IEnumerable<T> range) where T : class
{
    if (collection is null || range is null) { return 0; }
    int itemsAdded = 0;
    foreach (T item in range)
    {
        collection.Add(item);
        itemsAdded++;
    }
    return itemsAdded;
}

---

AddDistinct<T>

Adds an item to an ConcurrentBag<T> if the item does not already exist in the collection.

Returns true it the object was added successfully.

Parameter	Description
T	The Type of object contained within the collection.
collection	The ConcurrentBag<T> to be modified.
item	The Object to be added to the collection.

Method

public static bool AddDistinct<T>(this ConcurrentBag<T> collection, T item)
{
    bool added = false;
    if (!collection.Contains(item)) { collection.Add(item); added = true; }
    return added;
}

---

AddRangeDistinct<T>

Adds an object only if the object does not already exist in the ConcurrentBag<T> collection.

Returns an int representing the number of items successfully added to the collection.

Parameter	Description
T	The Type of object contained within the collection.
collection	The ConcurrentBag<T> to be modified.
range	The range of Objects to be added to the collection.

Method

public static int AddRangeDistinct<T>(this ConcurrentBag<T> collection, IEnumerable<T> range) where T : class
{
    if (collection is null || range is null) { return 0; }
    int itemsAdded = 0;
    foreach (T item in range)
    {
        if (!collection.Contains(item)) { collection.Add(item); itemsAdded++; }
    }
    return itemsAdded;
}

---

ICollection<T> Merge<T>

Merges up to two additional collections together with the current collection and returns a single collection with only one instance of each collection item from any of the collections. Whew!

Parameter	Description
T	The Type of object contained within the collection.
collection	The ICollection<T> to add the new collection to.
collectionA	An ICollection<T> to be added.
collectionB	An optional second ICollection<T> to be added.

#### Method

public static ICollection<T> Merge<T>(this ICollection<T> collection, ICollection<T> collectionA, ICollection<T> collectionB = null) where T : class
{
    if (collectionA is null && collectionB is null) { throw new ArgumentNullException("You must provide at least one collection for the merge command."); }
    ICollection<T> tempCol = new List<T>(collection);
    if (collectionA != null) { _ = tempCol.AddRangeDistinct(collectionA); }
    if (collectionB != null) { _ = tempCol.AddRangeDistinct(collectionB); }

    return tempCol;
}