/// <summary>
/// Internal method for the subtraction operation.
/// </summary>
/// <param name="bag">The bag to subtract from this bag.</param>
/// <returns>The result of the subtract operation.</returns>
private Bag <T> SubtractInternal(IBag <T> bag)
{
Guard.ArgumentNotNull(bag, "bag");
var resultBag = new Bag <T>(data);
using (var enumerator = bag.GetCountEnumerator())
{
while (enumerator.MoveNext())
{
var item = enumerator.Current;
int itemCount;
if (resultBag.data.TryGetValue(item.Key, out itemCount))
{
if (itemCount - item.Value <= 0)
{
resultBag.RemoveAll(item.Key);
}
else
{
resultBag.Remove(item.Key, item.Value);
}
}
}
}
return(resultBag);
}
/// <summary>
/// Internal method for the Intersection operation.
/// </summary>
/// <param name="bag">The bag to perform the intersection on.</param>
/// <returns>The result of the intersection.</returns>
private Bag <T> IntersectionInternal(IBag <T> bag)
{
Guard.ArgumentNotNull(bag, "bag");
var resultBag = new Bag <T>();
using (var enumerator = bag.GetCountEnumerator())
{
while (enumerator.MoveNext())
{
var item = enumerator.Current;
int itemCount;
if (data.TryGetValue(item.Key, out itemCount))
{
resultBag.Add(item.Key,
Math.Min(item.Value, itemCount)
);
}
}
}
return(resultBag);
}
/// <summary>
/// Internal method for the Union operation.
/// </summary>
/// <param name="bag">The bag to perform the union with.</param>
/// <returns>The result of the union operation.</returns>
private Bag <T> UnionInternal(IBag <T> bag)
{
Guard.ArgumentNotNull(bag, "bag");
var resultBag = new Bag <T>();
foreach (var item in data)
{
resultBag.Add(item.Key, item.Value);
}
using (var enumerator = bag.GetCountEnumerator())
{
while (enumerator.MoveNext())
{
var item = enumerator.Current;
resultBag.Add(item.Key, item.Value);
}
}
return(resultBag);
}
