/// <summary>
/// Splits a source <see cref="IEnumerable{T}"/> into several <see cref="IList{T}"/>s
/// with a max size of batchSize.
/// <remarks>Note that batchSize must be one or larger.</remarks>
/// </summary>
/// <param name="source">A sequence of values to split into smaller batches.</param>
/// <param name="batchSize">The number of elements to place in each batch.</param>
/// <returns>The original collection, split into batches.</returns>
public static IEnumerable <IList <T> > Batch <T>(this IEnumerable <T> source, int batchSize)
{
ArgumentUtility.CheckForNull(source, nameof(source));
ArgumentUtility.CheckBoundsInclusive(batchSize, 1, int.MaxValue, nameof(batchSize));
var nextBatch = new List <T>(batchSize);
foreach (T item in source)
{
nextBatch.Add(item);
if (nextBatch.Count == batchSize)
{
yield return(nextBatch);
nextBatch = new List <T>(batchSize);
}
}
if (nextBatch.Count > 0)
{
yield return(nextBatch);
}
}